Download +3.0V to+5.5V, 1µA, RS-232/RS-485/422 Multiprotocol Transceivers General Description Features

EVALUATION KIT AVAILABLE
LE
AVAILAB
+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
General Description
The MAX3160/MAX3161/MAX3162 are programmable
RS-232/RS-485/422 multiprotocol transceivers. The
MAX3160/MAX3161 are pin programmable as a 2TX/2RX
RS-232 interface or a single RS-485/422 transceiver. The
MAX3162 is configured as a 2TX/2RX RS-232 interface
and a single RS-485/422 transceiver simultaneously.
All devices incorporate a proprietary low-dropout transmitter output stage and an on-board dual charge pump
to allow RS-232 and RS-485/422 compliant performance from a +3V to +5.5V supply. The receivers
feature true fail-safe circuitry that guarantees a logichigh receiver output when the receiver inputs are open
or shorted. These devices also feature pin-selectable
transmitter slew rates for both RS-232 and RS-485/422
modes. Slew-rate limiting minimizes EMI and reduces
reflections caused by improperly terminated cables,
allowing error-free data transmission up to 250kbps.
Disabling slew-rate limiting allows these devices to
transmit at data rates up to 10Mbps in RS-485/422
mode and up to 1Mbps in RS-232 mode. The
MAX3160/MAX3161/MAX3162 feature a 1µA shutdown
mode, and short-circuit limiting and thermal shutdown
circuitry to protect against excessive power dissipation.
Features
♦ Single-Supply Operation from +3V to +5.5V
♦ Pin-Programmable as 2TX/2RX RS-232 or Single
RS-485/422 (MAX3160/MAX3161)
♦ 2TX/2RX RS-232 and Single RS-485/422
(MAX3162)
♦ Pin-Programmable RS-232/RS-485 Transmitter
Slew Rates Reduce EMI
♦ 10Mbps RS-485 and 1Mbps RS-232 Data Rates
♦ Pin-Programmable Half-Duplex or Full-Duplex
RS-485/422 Operation (MAX3160/MAX3161)
♦ RS-485/422 True Fail-Safe Receivers
♦ Transmitters and Receivers Protected Against
Wiring Faults
♦ 1µA Shutdown Supply Current
♦ 1/8-Unit Load Allows up to 256 Transceivers on
the Bus
The MAX3160/MAX3162 offer a flow-through pinout that
facilitates board layout. The MAX3160/MAX3161/
MAX3162 are available in tiny SSOP packages and
operate over the commercial and extended temperature ranges.
Typical Operating Circuit
________________________Applications
Functional Diagrams
Point-of-Sales Equipment
Peripherals
Industrial Controls
Networking
+3V TO +5.5V
1
RS-232 to RS-485
Interface Converters
RS485/RS232 11
PART
MAX3160CAP+
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
20 SSOP
MAX3160EAP+
-40°C to +85°C
20 SSOP
0°C to +70°C
24 SSOP
MAX3161EAG+
-40°C to +85°C
24 SSOP
MAX3162CAI+
0°C to +70°C
28 SSOP
MAX3162EAI+
-40°C to +85°C
28 SSOP
+Denotes a lead(Pb)-free/RoHS-compliant package.
Pin Configurations appear at end of data sheet.
Functional
Diagramsappear
continued
at end
of data
sheet.
Pin Configurations
at end
of data
sheet.
UCSP
is a Guide
trademark
of Maxim
Integrated
Selector
appears
at end
of dataProducts,
sheet. Inc.
DI/T1IN
Z(B)/T1OUT
16
RTS DE/T2IN
5
Y(A)/T2OUT
TX
Ordering Information
MAX3161CAG+
DB9
VCC
13
MAX3160
6
A/R2IN
MAX3100 11
15
RX RO/R2OUT
8
12
CTS R1OUT
10
13
B/R1IN
7
14
GND FAST HDPLX SHDN
SPI
μP
4
10
12
9
RJ45
SHDN
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
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19-1722; Rev 2; 12/09
+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
ABSOLUTE MAXIMUM RATINGS
Continuous Power Dissipation (TA = +70°C)
20-Pin SSOP (derate 11.9W/°C above +70°C) ..........952mW
24-Pin SSOP (derate 14.9W/°C above +70°C) ........1195mW
28-Pin SSOP (derate 15W/°C above +70°C) ...........1201mW
Operating Temperature Ranges
MAX316_CA_ ....................................................0°C to +70°C
MAX316_EA_ .................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
VCC to GND. .............................................................-0.3V to +6V
V+ to GND ................................................................-0.3V to +7V
V- to GND....................................................................0.3V to -7V
V+ - V- (Note 1)....................................................................+13V
Input Voltages
T1IN, T2IN, DI, DE485, RE485, TE232, RE232, SHDN,
FAST, HDPLX, RS485/RS232 to GND. ...............-0.3V to +6V
A, B, R1IN, R2IN to GND ...............................................±25V
Output Voltages
T1OUT, T2OUT, Y, Z to GND......................................±13.2V
R2OUT, R1OUT, RO to GND................-0.3V to (VCC + 0.3V)
Output Short-Circuit Duration
T1OUT, T2OUT, Y, Z ............................................Continuous
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +3V to +5.5V, C1–C4 = 0.1µF when tested at +3.3V ±10%; C1 = 0.047µF and C2, C3, C4 = 0.33µF when tested at +5V
±10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
DC CHARACTERISTICS
VCC Standby Current
VCC Shutdown Current
SYMBOL
ICC
ICC
CONDITIONS
MIN
TYP
MAX
MAX3160/MAX3161, no load,
RS485/ RS232 = GND
1.2
2.5
MAX3160/MAX3161, no load,
RS485/ RS232 = VCC
2.5
5.5
MAX3162 No Load
3.0
6
1
10
SHDN = GND, receiver inputs open or
grounded
UNITS
mA
µA
RS232)
TRANSMITTER AND LOGIC INPUTS (DI, T1IN, T2IN, DE485, R E4 8 5, TE232, R E 2 3 2, FAST, HDPLX, SHDN, RS485/R
Logic Input Low
Logic Input High
VIL
VIH
0.8
VCC = +3.3V
2.0
VCC = +5V
2.4
V
V
Logic Input Leakage Current
IINL
±0.01
Transmitter Logic Hysteresis
VHYS
0.5
±1
µA
V
RS-232 AND RS-485/422 RECEIVER OUTPUTS (R1OUT, R2OUT, RO)
Receiver Output Voltage Low
VOL
IOUT = 2.5mA
Receiver Output Voltage High
VOH
IOUT = -1.5mA
Receiver Output Short Circuit
Current
IOSR
0 < VO < VCC
Receiver Output Leakage
Current
IOZR
Receivers disabled
0.4
VCC - 0.6
V
V
±20
±60
mA
±0.05
±1
µA
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1–C4 = 0.1µF when tested at +3.3V ±10%; C1 = 0.047µF and C2, C3, C4 = 0.33µF when tested at +5V
±10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
RS-232 RECEIVER INPUTS (R1IN, R2IN)
CONDITIONS
MIN
Input Voltage Range
TYP
-25
Input Threshold Low
Input Threshold High
VCC = +3.3V
0.6
VCC = +5V
0.8
MAX
UNITS
25
V
V
VCC =+3.3V
2.0
VCC = +5V
2.4
Input Hysteresis
0.5
Input Resistance
3
V
V
5
7
kΩ
RS-485/422 RECEIVER INPUTS (NOTE 2)
Input Resistance
RIN
-7V < VCM < +12V
MAX3160
Input Current
IIN
MAX3161/MAX3162
Input Differential Threshold
Input Hysteresis
MAX3160
48
MAX3161/
MAX3162
96
kΩ
VCM = +12V
0.25
VCM = -7V
-0.15
VCM = +12V
0.125
VCM = -7V
VTH
-0.075
-50
-200
ΔVTH
mA
mV
30
mV
V
RS-232 TRANSMITTER OUTPUTS (T1OUT, T2OUT)
Both transmitter outputs loaded with 3kΩ
to GND
±5
±5.4
Output Resistance
VCC = V+ = V- = 0V, VT1OUT = VT2OUT = +2V
300
10M
Output Short-Circuit Current
T_OUT = GND
Output Leakage Current
VOUT = ±12V
TE232 = GND or SHDN =
GND
Output Voltage Swing
±30
Ω
±60
MAX3160/
MAX3161
±125
MAX3162
±25
mA
µA
RS-485/422 TRANSMITTER OUTPUTS (Y, Z)
Differential Output Voltage
VOD
R = 27Ω
(RS-485)
1.5
R = 50Ω
(RS-422)
2
Figure 1
Change in Magnitude of
Differential Output Voltage for
Complementary Output States
ΔVOD
R = 27Ω or 50Ω, Figure 1
Common Mode Output Voltage
VOC
Change in Magnitude of
Common Mode Output Voltage
for Complementary Output
States
Δ VOC
V
-0.2
0.2
V
R = 27Ω or 50Ω, Figure 1
3
V
R = 27Ω or 50Ω, Figure 1
0.2
V
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1–C4 = 0.1µF when tested at +3.3V ±10%; C1 = 0.047µF and C2, C3, C4 = 0.33µF when tested at +5V
±10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Output Short-Circuit Current
Output Leakage Current
SYMBOL
ISC
IO
CONDITIONS
VY or VZ = +12V to –7V
VY or VZ = +12V,
DE485 = GND or SHDN =
GND
MIN
TYP
MAX
±250
MAX3160/
MAX3161
±125
MAX3162
±25
UNITS
mA
µA
RS-232 TIMING CHARACTERISTICS (FAST = GND, 250kbps, ONE TRANSMITTER SWITCHING)
Maximum Data Rate
RL = 3kΩ, CL = 1000pF
Receiver Propagation Delay
R_IN to R_OUT, CL = 150pF
250
Receiver Output Enable Time
Receiver Output Disable Time
kbps
0.15
µs
200
ns
200
ns
Transmitter Skew
|tPHL - tPLH|
100
ns
Receiver Skew
|tPLH - tPHL|
50
ns
Transition-Region Slew Rate
VCC = +3.3V, TA = +25°C,
RL =3kΩ to 7kΩ, measured
from +3.0V or –3.0V to
+3.0V
CL = 150pF
to 1000pF
6
30
CL = 150pF
to 2500pF
4
30
V/µs
RS-232 TIMING CHARACTERISTICS (FAST = VCC, 1Mbps, ONE TRANSMITTER SWITCHING)
VCC = +3V to +4.5V, RL = 3kΩ, CL = 250pF
1
Maximum Data Rate
VCC = +4.5V to +5.5V, RL = 3kΩ,
CL = 1000pF
1
Receiver Propagation Delay
R_IN to R_OUT, CL = 150pF
Mbps
0.15
µs
Receiver Output Enable Time
200
ns
Receiver Output Disable Time
200
ns
Transmitter Skew
|tPHL - tPLH|
25
ns
Receiver Skew
|tPLH - tPHL|
50
ns
Transition-Region Slew Rate
VCC = +3.3V, TA = +25°C, RL =3kΩ to 7kΩ,
CL = 150pF to 1000pF, measured from
+3.0V or –3.0V to +3.0V
24
150
V/μs
RS-485/422 TIMING CHARACTERISTICS (FAST = GND) 250kbps
Driver Propagation Delay
tDPHL,
tDPLH
RDIFF = 54Ω, CL = 50pF, Figures 3, 5
200
400
800
ns
Driver Rise and Fall Time
tDPHL,
tDPLH
RDIFF = 54Ω, CL = 50pF, Figures 3, 5
200
400
800
ns
Driver Propagation Delay Skew
tDSKEW
RDIFF = 54Ω, CL = 50pF, Figure 3, 5
200
ns
Driver Output Enable Time
tDZH, tRZL
RDIFF = 54Ω, CL = 50pF, Figures 4, 6
400
800
ns
Driver Output Disable Time
tDLZ, tDHZ
RDIFF = 54Ω, CL = 50pF, Figure 4, 6
200
400
ns
Receiver Propagation Delay
tRPLH,
tRPHL
CL = 15pF, Figures 7, 9
80
150
ns
Receiver Propagation Delay
Skew
tRSKEW
CL = 50pF, Figures 7, 9
10
ns
25
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1–C4 = 0.1µF when tested at +3.3V ±10%; C1 = 0.047µF and C2, C3, C4 = 0.33µF when tested at +5V
±10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Receiver Output Enable Time
SYMBOL
tRZL, tRZH
CONDITIONS
CL = 50pF, Figures 2, 8
Receiver Output Disable Time
tRLZ, tRHZ
CL = 50pF, Figures 2, 8
MIN
TYP
100
MAX
UNITS
ns
100
ns
RS-485/RS-422 TIMING CHARACTERISTICS (FAST = VCC, 10Mbps)
Driver Propagation Delay
tDPHL,
tDPLH
RDIFF = 54Ω, CL = 50pF, Figures 3, 5
60
120
ns
Driver Rise And Fall Times
tDR, tDF
RDIFF = 54Ω, CL = 50pF, Figures 3, 5
10
25
ns
Driver Propagation Delay Skew
tDSKEW
RDIFF = 54Ω, CL = 50pF, Figures 3, 5
tDZL
tDLZ, tDHZ
tRPLH,
tRPHL
RDIFF = 54Ω, CL = 50pF, Figures 4, 6
Driver Output Enable Time
Driver Output Disable Time
Receiver Propagation Delay
Receiver Propagation Delay
Skew
Receiver Output Enable Time
Receiver Output Disable Time
10
ns
400
800
ns
RDIFF = 54Ω, CL = 50pF, Figures 4, 6
200
400
ns
CL = 15pF, Figures 7, 9
80
150
ns
10
ns
tRSKEW
CL = 50pF, Figures 7, 9
tRZL, tRZH
tRLZ, tRHZ
CL = 50pF, Figures 2, 8
CL = 15pF, Figures 2, 8
100
100
ns
ns
Note 2: Applies to A, B for MAX3162 and MAX3160/MAX3161 with HDPLX = GND, or Y, Z for MAX3160/MAX3161 with HDPLX = VCC.
Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all RS-232 transmitters (RS-232 mode) loaded with 3kΩ to ground, TA = +25°C,
unless otherwise noted.)
RS-232 TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (FAST = VCC)
2.5
0
-2.5
-5.0
7.5
5.0
2.5
0
-2.5
-5.0
-7.5
-7.5
-10.0
-10.0
0
1000
2000
3000
4000
LOAD CAPACITANCE (pF)
5000
16
14
SLEW RATE (V/μs)
5.0
18
MAX3160/2 TOC2
7.5
10.0
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3160/2 TOC1
TRANSMITTER OUTPUT VOLTAGE (V)
10.0
RS-232 TRANSMITTER SLEW RATE vs.
LOAD CAPACITANCE (FAST = GND)
MAX3160/2 TOC3
RS-232 TRANSMITTER OUTPUT VOLTAGE vs.
LOAD CAPACITANCE (FAST = GND)
12
10
8
6
4
2
0
0
500
1000
1500
LOAD CAPACITANCE (pF)
2000
0
1000
2000
3000
4000
LOAD CAPACITANCE (pF)
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5000
+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all RS-232 transmitters (RS-232 mode) loaded with 3kΩ to ground, TA = +25°C,
unless otherwise noted.)
MAX3160/MAX3161
OPERATING SUPPLY CURRENT vs.
RS-232 TRANSMITTER SLEW RATE
NO-LOAD SUPPLY CURRENT vs.
LOAD CAPACITANCE WHEN
vs. LOAD CAPACITANCE (FAST = VCC)
TEMPERATURE
TRANSMITTING DATA (RS-232 MODE)
70
60
50
40
30
20
1Mbps
40
250kbps
30
20
MAX3160/2 TOC6
2.5
SUPPLY CURRENT (mA)
50
SUPPLY CURRENT (mA)
80
3.0
MAX3160/2 TOC5
90
SLEW RATE (V/μs)
60
MAX3160/2 TOC4
100
20kbps
RS-485 MODE
2.0
1.5
RS-232 MODE
1.0
10
10
0
500
1000
1500
2000
1000
2000
3000
4000
-40
5000
-15
10
35
60
LOAD CAPACITANCE (pF)
TEMPERATURE (°C)
SHUTDOWN CURRENT vs. TEMPERATURE
RS-485/422 OUTPUT CURRENT vs.
DRIVER OUTPUT VOLTAGE
RS-485/422 OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
100
80
60
40
100
80
60
40
MAX3160/2 TOC9
160
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
120
120
85
180
MAX3160/2 TOC8
140
MAX3160/2 TOC7
140
140
120
100
80
60
40
20
20
20
0
0
-40
-15
10
35
60
0
0
85
2
4
6
8
10
12
-7
-5
-3
-1
1
3
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
RS-485/422 DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
RS-485/422 DRIVER DIFFERENTIAL OUTPUT
vs. TEMPERATURE
OUTPUT CURRENT vs. RECEIVER
OUTPUT LOW VOLTAGE
1
0.1
3.2
3.1
3.0
2.9
2.8
2.7
0.01
30
5
MAX3160/2 TOC12
3.3
OUTPUT VOLTAGE (V)
10
R = 50Ω
3.4
25
OUTPUT CURRENT (mA)
3.5
MAX3160/2 TOC10
100
MAX3160/2 TOC11
SHUTDOWN CURRENT (nA)
0
LOAD CAPACITANCE (pF)
160
OUTPUT CURRENT (mA)
0
0
0
20
15
10
5
2.6
2.5
0.001
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT VOLTAGE (V)
3.5
4.0
0
-40
-15
10
35
TEMPERATURE (°C)
60
85
0
0.5
1.0
1.5
2.0
2.5
OUTPUT LOW VOLTAGE (V)
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3.0
3.5
+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all RS-232 transmitters (RS-232 mode) loaded with 3kΩ to ground, TA = +25°C,
unless otherwise noted.)
8
6
4
RISING
0
FALLING
60
40
0.5
1.0
1.5
2.0
2.5
3.0
3.5
65
55
50
-40
-15
10
35
60
85
-40
-15
10
35
60
OUTPUT HIGH VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
RS-485/422 DRIVER PROPAGATION DELAY
vs. TEMPERATURE (SLOW)
RS-485/422 DRIVER PROPAGATION
(FAST, 10Mbps)
RS-485/422 DRIVER PROPAGATION
(SLOW, 250kbps)
MAX3160/2 TOC19
480
R = 50Ω
460
85
MAX3160/2 TOC21
MAX3160/2 TOC20
500
DI
5V/div
440
TIME (ns)
70
60
0
0
R = 50Ω
80
75
80
20
2
85
TIME (ns)
10
CL = 50pF
100
RS-485/422 DRIVER PROPAGATION DELAY
vs.TEMPERATURE (FAST)
MAX3160/2 TOC16
MAX3160/2 TOC13
OUTPUT CURRENT (mA)
12
120
PROPAGATION DELAY (ns)
14
RS-485/422 RECEIVER PROPAGATION DELAY
vs. TEMPERATURE
MAX3160/2 TOC18
OUTPUT CURRENT vs. RECEIVER
OUTPUT HIGH VOLTAGE
DI
5V/div
420
400
VY-VZ
2V/div
380
VY-VZ
2V/div
360
340
320
300
-40
-15
10
35
60
20ns/div
1.0μs/div
RS-485/422 RECEIVER PROPAGATION
(FAST, 5Mbps)
RS-485/422 DRIVER DISABLE/ENABLE
TO DRIVER OUTPUT
85
TEMPERATURE (°C)
I-V OUTPUT IMPEDANCE CURVE
IN RS-232 SHUTDOWN MODE
MAX3160/2 TOC24
MAX3160/2 TOC22
MAX3160-A
400
200
0
CURRENT (μA)
DE485
2V/div
VY-VZ
2V/div
R = 50Ω
CL = 82pF
-200
-400
CL = 50pF
RO
2V/div
-600
VY - VZ
2V/div
-800
-1000
-20
-15
-10
-5
0
5
10
15
20
40ns/div
100ns/div
VOLTS (V)
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Pin Description
PIN
MAX3160
MAX3161
MAX3162
NAME
FUNCTION
1
1
1
C1+
Positive Terminal of the Positive Flying Capacitor
2
2
2
VCC
Positive Supply Voltage
3
3
3
C1-
4
4
4
GND
—
5
5
T1OUT
5
—
—
Z(B)/T1OUT
—
—
6
Z
—
6
—
Z(B)
6
—
—
Y(A)/T2OUT
—
—
7
Y
—
7
—
Y(A)
Negative Terminal of the Positive Flying Capacitor
Ground
RS-232 Driver Output
Inverting RS-485/422 Driver Output in Full-Duplex Mode
(and Inverting RS-485/422 Receiver Input in Half-Duplex
Mode)/RS-232 Driver Output
Inverting RS-485/422 Driver Output
Inverting RS-485/422 Driver Output in Full-Duplex Mode
(and Inverting RS-485/422 Receiver Input in Half-Duplex
Mode)
Noninverting RS-485/422 Driver Output in Full-Duplex
Mode (and Noninverting RS-485/422 Receiver Input in
Half-Duplex Mode)/RS-232 Driver Output
Noninverting RS-485/422 Driver Output
Noninverting RS-485/422 Driver Output in Full-Duplex
Mode (and Noninverting RS-485/422 Receiver Input in
Half-Duplex Mode)
7
9
9
R1OUT
—
8
8
T2OUT
RS-232 Receiver Output
8
10
—
RO/R2OUT
RS-485/422 Receiver Output/RS-232 Receiver Output
9
11
13
SHDN
Active-Low Shutdown-Control Input. Drive low to shut
down transmitters and charge pump.
—
—
10
R2OUT
RS-232 Driver Output
RS-232 Driver Output
Select slew rate limiting for both RS-232 and RS485/422. Slew rate limits with a logic-level low.
10
12
14
FAST
—
—
11
RO
11
13
—
RS485/RS232
—
—
12
RE485
RS-485/422 Receiver Enable. Logic-level low enables
RS-485/422 receivers.
12
14
—
HDPLX
Software-Programmable Pin Functionality. Operates in
full-duplex mode when low; operates in half-duplex
mode when high.
RS-485/422 Receiver Output
Software-Programmable Pin Functionality. Operates as
RS-485/422 with a logic-level high; operates as RS-232
with a logic-level low.
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Pin Description (continued)
PIN
NAME
FUNCTION
MAX3160
MAX3161
MAX3162
13
—
—
A/R2IN
Noninverting RS-485/422 Receiver Input/RS-232
Receiver Input
14
—
—
B/R1IN
Inverting RS-485/422 Receiver Input/RS-232 Receiver
Input
—
—
15
RE232
RS-232 Receiver Enable. Logic-level low enables RS232 receivers.
—
15
17
A
15
19
—
DE485/T2IN
—
—
16
TE232
—
16
18
B
16
20
—
DI/T1IN
—
17
19
R2IN
17
21
25
V-
Noninverting RS-485/422 Receiver Input
RS-485/RS-422 Driver Enable/RS-232 Driver Input
RS-232 Transmitter Output Enable
Inverting RS-485/422 Receiver Input
RS-485/RS-422 Driver Input/RS-232 Driver Input
RS-232 Receiver Input
Negative Charge-Pump Rail
—
18
20
R1IN
18
22
26
C2-
Negative Terminal of the Negative Flying Capacitor
RS-232 Receiver Input
19
23
27
C2+
Positive Terminal of the Negative Flying Capacitor
20
24
28
V+
—
—
21
T2IN
—
—
22
DE485
—
—
23
DI
—
—
24
T1IN
Positive Charge-Pump Rail
RS-232 Driver Input
RS-485/RS-422 Driver Enable
RS-485/RS-422 Driver Input
RS-232 Driver Input
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Functional Diagrams
MAX3160
RS-485 MODE
RS-232 MODE
VCC
VCC
1
C1+
V+
1
20
C3
C1
2
3
VCC
C2+
CHARGE
PUMP
C1-
2
19
C2
C2-
3
18
CBYPASS
CBYPASS
4
GND
C1
V-
4
17
C1+
V+
VCC
C2+
C1-
5
6
LOGIC
OUTPUTS
7
8
9 SHDN
10 FAST
T1
T2
R1
R2
5
16
15
LOGIC
INPUTS
13
HDPLX 12
RS485/RS232 11
RS-485
OUTPUTS
VZ
6
RS-232
INPUTS
C3
18
17
9 SHDN
10 FAST
C4
16
LOGIC
INPUTS
Y
R0
LOGIC
OUTPUT 8
C2
19
D
15
DE
B
7
14
C2-
GND
C4
RS-232
OUTPUTS
CHARGE
PUMP
20
R
A
14
RS-485
INPUTS
13
12
RS485/RS232 11
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Functional Diagrams (continued)
MAX3161
RS-232 MODE
RS-485 MODE
VCC
VCC
1
C1+
V+
24
C3
C1
2
3
VCC
C2+
CHARGE
PUMP
C1-
1 C1+
V+
VCC
C2+
23
2
C2
C2-
3
22
CBYPASS
CBYPASS
4
GND
V-
4
21
24
C3
C1
CHARGE
PUMP
C1-
C2-
GND
V-
23
C2
22
21
C4
RS-232
OUTPUT
5
T1
6
19
7
RS-232
OUTPUT
8
9
LOGIC
OUTPUTS
10
11 SHDN
12 FAST
5
20
LOGIC
INPUTS
R1
R2
17
16
15
HDPLX 14
RS485/RS232 13
RS-232
INPUTS
20
LOGIC
INPUTS
Z
19
D
7
18
T2
6
RS-485
OUTPUTS
C4
Y
18
DE
8
17
B
9
R0
LOGIC
OUTPUT 10
11 SHDN
12 FAST
R
A
16
RS-485
INPUTS
15
14
RS485/RS232 13
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Multiprotocol Transceivers
Functional Diagrams (continued)
Test Circuits
MAX3162
Y
R
VOD
VCC
1
C1+
V+
28
R
C3
C1
2
3
VCC
C2+
CHARGE
PUMP
C1-
C2-
27
Z
C2
26
Figure 1. RS-485/422 Driver DC Test Load
CBYPASS
4
GND
V-
6
RS-485
OUTPUTS
7
25
C4
T1
RS-232
5
OUTPUT
VOC
24
Z
23
D
Y
DE485
LOGIC
INPUTS
22
RECEIVER
OUTPUT
1k
TEST POINT
VCC
S1
CL
1k
T2
RS-232
8
OUTPUT
211
S2
R1
9
LOGIC
OUTPUTS
10
20
RS-232
INPUTS
R2
19
B
11
RO
12
RE485
13 SHDN
18
RS-485
INPUTS
R
A
TE232
Figure 2. RS-485/422 Receiver Enable/Disable Timing Test Load
17
3V
16
DE485
14 FAST
CL
15
DI
Y
VOD RDIFF
Z
CL
Figure 3. RS-485/422 Driver Timing Test Circuit
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Test Circuits (continued)
3V
DI
1.5V
0
OUTPUT
UNDER TEST
500Ω
1.5V
tDPHL
tDPLH
1/2 VO
VCC
S1
Z
VO
Y
CL
S2
VDIFF
VO
0
-VO
1/2 VO
10%
VDIFF = Vy - Vz
90%
90%
TDR
10%
TDF
tDSKEW = | tDPLH - tDPHL |
Figure 4. RS-485/422 Driver Enable/Disable Timing Test Load
3V
DE485
0
1.5V
1.5V
tDZL
tDLZ
RO
Y, Z
2.3V OUTPUT NORMALLY LOW
VOL
tDZH
1V
A
-1V
B
VCC/2
VCC/2
OUTPUT
tRPHL
tRPLH
INPUT
tDHZ
Figure 6. RS-485/422 Driver Enable and Disable Times
1.5V
Figure 7. RS-485/422 Receiver Propagation Delays
1.5V
tRZL
B
tRLZ
1.5V OUTPUT NORMALLY LOW
VOL + 0.5V
OUTPUT NORMALLY HIGH
RO
VOL
VOH -0.5V
2.3V
0
VCC
RO
VOH
VOL +0.5V
OUTPUT NORMALLY HIGH
Y, Z
3V
RE485
0
Figure 5. RS-485/422 Driver Propagation Delays
VID
R
A
RO
CL
VOH - 0.5V
1.5V
0
tRZH
tRHZ
Figure 8. MAX3162 RS-485/422 Receiver Enable and Disable
Times
Figure 9. RS-485/422 Receiver Propagation Delays Test Circuit
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Detailed Description
The MAX3160/MAX3161/MAX3162 3V/5V, multiprotocol
transceivers can be pin configured in a number of RS232 and RS-485/422 interface combinations. These circuit configurations are ideal for the design of RS-232 to
RS-485 converters, multiprotocol buses, or any application that requires both RS-232 and RS-485 transceivers.
The slew rate of these devices is on-the-fly pin programmable, allowing reduced EMI data rates, or up to
10Mbps RS-485 communications. Power consumption
can be reduced to 1µA by using the shutdown function,
but the RS-232 receivers remain active allowing other
devices to query the interface controller. A flow-through
pinout and the space-saving SSOP packages (available in the commercial and extended temperature
ranges) facilitate board layout.
Device Selection
The MAX3160/MAX3161/MAX3162 contain RS-232
transceivers and an RS-485/422 transceiver. The primary difference between the devices is the multiplexing
of the I/O pins.
The MAX3160 has common transmitter outputs and
receiver inputs for its RS-232 and RS-485/422 transceivers, and common digital I/O pins. The MAX3160 is
optimized for multiprotocol operation on a single interface bus and comes in a 20-pin SSOP.
The MAX3161 has separate transmitter outputs and
receiver inputs for its RS-232 and RS-485/422 transceivers, and common digital I/O pins. The MAX3161 is
optimized for multiplexing a single UART across two
interface buses and comes in a 24-pin SSOP.
The MAX3162 has separate transmitter outputs and
receiver inputs for its RS-232 and RS-485/422 transceivers, and separate digital I/O pins. The MAX3162 is
optimized for protocol translation between two interface
buses and comes in a 28-pin SSOP.
See Tables 1–12, Functional Diagrams, and the following descriptions for details on each device.
MAX3160
The MAX3160 is a 2TX/2RX RS-232 transceiver in RS232 mode, capable of RS-232-compliant communication. Assertion of RS-485/RS232 converts the device to
a single RS-485 transceiver by multiplexing the RS-232
I/O pins to an RS-485 driver and receiver pair. The
logic inputs now control the driver input and the driver
enable. One logic output carries the RS-485 receiver
output, and the other is three-stated. The receiver input
impedance is dependent on the device mode and is
1/4-unit load for RS-485 operation and 5kΩ for RS-232
operation.
MAX3161
The MAX3161 is a 2TX/2RX RS-232 transceiver in RS232 mode or a single RS-485/422 transceiver in RS-485
mode. When in RS-485 mode, the unused RS-232
transmitter and receiver output pins are disabled. When
in RS-232 mode, the RS-485 transmitter outputs are
disabled and the RS-232 receiver inputs are 5kΩ to
GND. The RS-485 receiver inputs are always 1/8-unit
load. Logic lines are shared between the two protocols
and are used for signal inputs and as an RS-485 driver
enable.
MAX3162
The MAX3162 is a 2TX/2RX RS-232 transceiver and a
single RS-485/422 transceiver simultaneously. All drivers, receivers, and transmitters can be enabled or disabled by pin configuration. All outputs are high-Z when
not activated. RS-232 receiver inputs are 5kΩ when
enabled, and RS-485 receiver inputs are 1/8-unit load.
FAST Mode operation
The FAST control pin is used to select the slew-rate limiting of the RS-232 transmitters and the RS-485/422 drivers. With FAST unasserted, the RS-232 transmitters
and the RS-485/422 driver are slew-rate limited to
reduce EMI. RS-232 data rates up to 1Mbps and RS485/422 data rates up to 10Mbps are possible when
FAST is asserted. FAST can be changed during operation without interrupting data communications.
Half-Duplex RS-485/422 Operation
Asserting HDPLX places the MAX3160/MAX3161 in
half-duplex mode. The RS-485 receiver inputs are internally connected to the driver outputs. The RS-485 driver outputs can be disabled by pulling DE485 low.
HDPLX has no affect on RS-232 operation.
Low-Power Shutdown
The MAX3160/MAX3161/MAX3162 have an active-low
shutdown control input, SHDN. When driven low, the
charge pump and transmitters are shut down and supply current is reduced to 1µA. The RS-232 receiver outputs remain active if in RS-232 mode. The chargepump capacitors must be recharged when coming out
of shutdown before resuming operation in either RS-232
or RS-485/422 mode (Figure 10).
Dual Charge-Pump Voltage Converter
The MAX3160/MAX3161/MAX3162s’ internal power
supply consists of a regulated dual charge pump that
provides output voltages of +5.5V (doubling charge
pump) and -5.5V (inverting charge pump) for input voltages (VCC) over the 3.0V to 5.5V range. The charge
pumps operate in a discontinuous mode: if the magnitude of either output voltage is less than 5.5V, the
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charge pumps are enabled; if the magnitude of both
output voltages exceeds 5.5V, the charge pumps are
disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies (see Functional
Diagrams).
RS-485/422 Transceivers
The MAX3160/MAX3161/MAX3162 RS-485/422 transceivers feature fail-safe circuitry that guarantees a
logic-high receiver output when the receiver inputs are
open or shorted, or when they are connected to a terminated transmission line with all drivers disabled (see
Fail-Safe). The MAX3160/MAX3161/MAX3162 also feature pin-selectable reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly
terminated cables, allowing error-free data transmission
up to 250kbps (see RS-485/422 Reduced EMI and
Reflections). The transmitters may operate at speeds
up to 10Mbps with the slew-rate limiting disabled.
Drivers are short-circuit current limited and thermally
limited to protect them against excessive power dissipation. Half-duplex communication is enabled by driving HDPLX high.
Fail-Safe
The MAX3160/MAX3161/MAX3162 guarantee a logichigh RS-485 receiver output when the receiver inputs
are shorted or open, or when they are connected to a
terminated transmission line with all drivers disabled.
This is done by having the receiver threshold between
-50mV and -200mV. If the differential receiver input voltage (A-B) is greater than or equal to -50mV, RO is logic
high. If A-B is less than or equal to -200mV, RO is logic
low. In the case of a terminated bus with all transmitters
disabled, the receiver’s differential input voltage is
pulled to GND by the termination. This results in a logic
high with a 50mV minimum noise margin. Unlike other
fail-safe devices, the -50mV to -200mV threshold complies with the ±200mV EIA/TIA-485 standard.
RS-232 Transceivers
The MAX3160/MAX3161/MAX3162 RS-232 transmitters
are inverting-level translators that convert CMOS-logic
levels to ±5.0V EIA/TIA-232-compliant levels. The transmitters are guaranteed at a 250kbps data rate in slewrate limited mode (FAST = GND) with worst-case loads
of 3kΩ in parallel with 1000pF. Data rates up to
1Mbps can be achieved by asserting FAST.
When powered down or in shutdown, the MAX3160/
MAX3161/MAX3162 outputs are high impedance and
can be driven to ±12V. The transmitter inputs do not
have pullup resistors. Connect unused inputs to ground
or VCC.
The receivers convert RS-232 signals to CMOS-logic output levels. All receivers have inverting outputs that
remain active in shutdown. The MAX3160/MAX3161/
MAX3162 permit their receiver inputs to be driven to Dia
±25V. Floating receiver input signals are pulled to
ground through internal 5kΩ resistors, forcing the outputs to a logic high. The MAX3162 has transmitter and
receiver enable pins that allow its outputs to be threestated.
Applications Information
Capacitor Selection
The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors
can be used. Ceramic chip capacitors with an X7R
dielectric provide the best combination of performance,
cost, and size. The charge pump requires 0.1µF
capacitors for 3.3V operation. For other supply voltages, see Table 13 for required capacitor values. Do
not use values smaller than those listed in Table 13.
Increasing the capacitor values reduces ripple on the
transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be changed without
changing C1’s value. However, do not increase C1
without also increasing the values of C2, C3, C4,
and CBYPASS to maintain the proper ratios to the
other capacitors.
When using the minimum required capacitor values,
make sure the capacitance value does not degrade
excessively with temperature or voltage. This is typical
of Y5V and Z5U dielectric ceramic capacitors. If in
doubt, use capacitors with a larger nominal value. The
capacitor’s equivalent series resistance (ESR), which
usually rises at low temperatures, influences the
amount of ripple on V+ and V-.
Power-Supply Decoupling
In applications that are sensitive to power-supply noise,
decouple VCC to ground with a capacitor of the same
value as reservoir capacitors C2, C3, and C4. Connect
the bypass capacitor as close to the IC as possible.
RS-232 Transmitter Outputs
when Exiting Shutdown
Figure 10 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 levels (one transmitter input is high, the other is low). Each
transmitter is loaded with 3kΩ in parallel with 1000pF.
The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that
the transmitters are enabled only when V- exceeds
approximately -3V.
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Truth Tables
RS-232 Receivers
RS-232 Transmitters
Table 4. MAX3160
Table 1. MAX3160
INPUTS
INPUTS
SHDN
RS485
RS232
DI/T1IN,
DE485/T2IN
OUTPUTS
OUTPUTS
SHDN
Z(B)/T1OUT,
Y(A)/T2OUT
RS-485/
RS-232
B/R1IN,
A/R2IN
R1OUT,
RO/R2OUT
X
0
0
1
X
0
1
0
X
0
Inputs Open
0
X
X
1/8 Unit Load
1
0
0
1
1
0
1
0
1
1
X
RS-485 Mode
X
1
X
1
R1OUT
High-Z,
RO/R2OUT in
RS-485 mode
Table 5. MAX3161
Table 2. MAX3161
INPUTS
INPUTS
OUTPUTS
OUTPUTS
SHDN
RS-485/
RS-232
R1IN, R2IN
R1OUT,
RO/R2OUT
1
SHDN
RS-485/
RS-232
DI/T1IN,
DE485/T2IN
T1OUT,
T2OUT
X
0
0
0
X
X
High-Z
X
0
1
0
1
0
0
1
X
0
Inputs Open
1
1
0
1
0
1
1
X
High-Z
X
1
X
R1OUT
High-Z,
RO/R2OUT in
RS-485 mode
Table 6. MAX3162
Table 3. MAX3162
INPUTS
SHDN
TE232
T1IN,T2IN
0
X
1
1
X
0
1
1
X
X
0
1
OUTPUTS
T1OUT,
T2OUT
High-Z
High-Z
1
0
High Data Rates
The MAX3160/MAX3161/MAX3162 maintain the RS-232
±5.0V required minimum transmitter output voltage even
at high data rates. Figure 11 shows a transmitter loopback test circuit. Figure 12 shows a loopback test result
at 250kbps, and Figure 13 shows the same test at
1000kbps. Figure 12 demonstrates a single slew-rate
limited transmitter driven at 250kbps (FAST = GND) into
an RS-232 load in parallel with 1000pF. Figure 13 shows
INPUTS
OUTPUTS
SHDN
RE232
R1IN, R2IN
R1OUT,
R2OUT
X
1
X
High-Z
X
0
0
1
X
0
1
0
X
0
Inputs open
1
a single transmitter driven at 1Mbps (FAST asserted),
loaded with an RS-232 receiver in parallel with 1000pF.
These transceivers maintain the RS-232 ±5.0V minimum
transmitter output voltage at data rates up to 1Mbps.
256 Transceivers on the Bus
The standard RS-485 receiver input impedance is 12kΩ
(one-unit load), and the standard driver can drive up to
32-unit loads. The MAX3160 has a 1/4-unit load receiver input impedance (48kΩ), allowing up to 128 trans-
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Truth Tables (continued)
RS-485/422 Drivers
Table 7. MAX3160
INPUTS
OUTPUTS
SHDN
RS232
RS485/R
DE485/T2IN
DI/T1IN
Z(B)/T1OUT
Y(A)/T2OUT
0
1
X
X
1/8 Unit Load
1/8 Unit Load
1
1
0
X
1/8 Unit Load
1/8 Unit Load
1
1
1
0
1
0
1
1
1
1
0
1
X
0
X
X
RS-232 Mode
Table 8. MAX3161
INPUTS
OUTPUTS
SHDN
RS232
RS485/R
DE485/T2IN
DI/T1IN
Z(B)
Y(A)
0
X
X
X
1/8 Unit Load
1/8 Unit Load
X
0
X
X
1/8 Unit Load
1/8 Unit Load
X
X
0
X
1/8 Unit Load
1/8 Unit Load
1
1
1
0
1
0
1
1
1
1
0
1
Table 9. MAX3162
INPUTS
OUTPUTS
SHDN
DE485
DI
Z
Y
0
X
X
High-Z
High-Z
X
0
X
High-Z
High-Z
1
1
0
1
0
1
1
1
0
1
RS-485/422 Receivers
Table 10. MAX3160
INPUTS
RS485/RS232
SHDN
HDPLX
1
0
1
1
OUTPUT
A - B*
Y - Z*
RO/R2OUT
X
X
X
High-Z Up to VCC
0
≥-50mV
X
1
0
1
1
0
≤-200mV
X
1
1
0
Floating
X
1
1
1
1
X
≥-50mV
1
1
1
1
X
≤-200mV
0
1
1
1
X
Floating
1
0
X
X
X
X
RS-232 Mode
*Y and Z correspond to pins Y(A)/T2OUT and Z(B)/T1OUT. A and B correspond to pins A/R2IN and B/R1IN.
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Truth Tables (continued)
Table 11. MAX3161
INPUTS
OUTPUT
RS485/RS232
SHDN
HDPLX
A-B
Y(A) - Z(B)
RO/R2OUT
1
0
X
X
X
High-Z up to VCC
1
1
0
-50mV
X
1
1
1
0
-200mV
X
0
1
1
0
Floating
X
1
1
1
1
X
-50mV
1
1
1
1
X
-200mV
0
1
1
1
X
Floating
1
0
X
X
X
X
RS-232 Mode
Table 12. MAX3162
INPUTS
OUTPUT
SHDN
RE485
A-B
RO
Table 13. Required Minimum Capacitance
Values
0
X
X
High-Z
SUPPLY VOLTAGE
(V)
X
1
X
High-Z
+3.0 TO +3.6
0.1
0.1
1
0
-50mV
1
+4.5 TO +5.5
0.047
0.33
+3.0 TO +5.5
0.1
0.47
1
0
-200mV
0
1
0
Inputs Open
1
ceivers to be connected in parallel on one communication line. The MAX3161/MAX3162 have a 1/8-unit load
receiver input impedance (96kΩ), allowing up to 256
transceivers to be connected in parallel on one communication line. Any combination of these devices
and/or other RS-485 transceivers with a total of 32-unit
loads or fewer can be connected to the line.
The MAX3160/MAX3161/MAX3162 RS-485 driver outputs are 1/8-unit load when disabled This impedance
may be reduced if the D1 pin is toggled at a high frequency. With no power applied (VCC = GND), the RS485 transmitter output impedances typically go to 1/2unit load on the MAX3161/MAX3162, and to one-unit
load on the MAX3160.
Driver Output Protection
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus contention. The first, a foldback current limit on the output
stage, provides immediate protection against short circuits over the whole common-mode voltage range (see
C1 (µF)
C2, C3, C4, CBYPASS
(µF)
Typical Operating Characteristics). The second, a thermal shutdown circuit, forces the driver outputs into a
high-impedance state if the die temperature becomes
excessive.
Protection Against Wiring Faults
EIA/TIA-485 standards require a common input voltage
range of -7V to +12V to prevent damage to the device.
The MAX3160/MAX3161/MAX3162 inputs are protected
to RS-232 levels of ±25V for the receiver inputs and
±13.2V for the transmitter/driver outputs. This provides
additional protection for the RS-485 transceivers
against ground differential or faults due to miswiring.
RS-485/422 Reduced EMI and Reflections
The MAX3160/MAX3161/MAX3162 can be configured
for slew-rate limiting by pulling FAST low. This minimizes
EMI and reduces reflections caused by improperly terminated cables. Operation in slew-rate limited mode
reduces the amplitudes of high-frequency harmonics.
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
MAX 3160-2 FIG10
MAX 3160-2 FIG12
SHDN
5V/division
TIN
T1OUT
2V/div
TOUT
GND
5V/div
T2OUT
2V/div
ROUT
40μs/div
1μs/div
Figure 10. MAX3160 RS-232 Transmitter Outputs When Exiting
Shutdown
Figure 12. RS-232 Loopback Test Result at 250kbps, FAST =
Low
MAX 3160-2 FIG13
VCC
CBYPASS
TIN
VCC
C1+
TOUT
V+
C1
C3
C1C2+
C2
C2-
5V/div
MAX3160
MAX3161
MAX3162
VC4
ROUT
T_ OUT
T_ IN
200ns/div
Figure 13. RS-232 Loopback Test Result at 1000kbps, FAST =
High
R_ IN
R_ OUT
1000pF
5k
VCC
SHDN
GND
Figure 11. Loopback Test Circuit
RS-485/422 Line Length vs. Data Length
The RS-485/422 standard covers line lengths up to
4000 feet. For line lengths greater than 4000 feet, use
the repeater application shown in Figure 14.
RS-232/RS-485 Protocol Translator
Figure 15 shows the MAX3162 configured as an RS232/RS-485 protocol translator. The direction of translation is controlled through the RTS signal (R1IN). The
single-ended RS-232 receiver input signal is translated
to a differential RS-485 transmitter output. Similarly, a
differential RS-485 receiver input signal is translated to
a single-ended RS-232 transmitter output. RS-232 data
received on R2IN is transmitted as an RS-485 signal on
Z and Y. RS-485 signals received on A and B are transmitted as an RS-232 signal on T1OUT.
Multiprotocol Bus
The Typical Operating Circuit shows a standard application for the MAX3160. The MAX3160’s output pins
are multiplexed between RS-232 and RS-485 protocols
by a microprocessor (µP). The µP also directs the shutdown functions, enable lines, and the duplex of the
MAX3160. Data is transmitted to the MAX3100 UART
through an SPI™ port. The UART asynchronously
SPI is a trademark of Motorola, Inc.
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
3.3V
MAX3160
MAX3161
MAX3162
A
CBYPASS
100nF
120Ω
RO
R
RE485
2
DATA IN
B
27
C2
100nF
DE485
Z
DI
D
Y
26
120Ω
13
DATA OUT
5
RCV
10
23
NOTE: RE485 ON MAX3162 ONLY
19
TX
20
RTS
15
Figure 14. RS-485 Line Repeater
16
14
transfers data through the MAX3160 to the pin-selected
RS-232 or RS-485 protocol; see Table 14 for commonly
used cable connections.
28
C2+
VCC
C1+
C2- MAX3162
C1-
1
3
SHDN
T1OUT
T1IN
24
R2IN
11
RO
9
R1OUT
12
RE485
22
DE485
R1IN
A
RE232
B
TE232
Z
FAST
Y
R2OUT
DI
V+
C3
100nF
GND
V-
17
18
6
7
25
4
Multiprotocol Bus Multiplexer
The Typical Application Circuit shows the MAX3161 configured as a multiprotocol bus multiplexer. The MAX3161
separates the RS-232 and RS-485 lines, but shares the
logic pins between modes. This application allows the
µP to monitor a point-to-point RS-232 bus, and a multidrop RS-485 interface. The MAX3100 UART asynchronously transfers data through the MAX3161 to the
pin-selected RS-232 or RS-485 protocol.
C1
100nF
Figure 15. Protocol Translator
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C4
100nF
+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Table 14. Cable Connections Commonly Used for EIA/TIA-232 and
V.24 Asynchronous Interfaces
EIA/TIA-232
STANDARD
CONNECTOR
PIN
MAX3160
MAX3161
MAX3162
EQUIVALENT
MAX3160
MAX3161
MAX3162
PIN NUMBER
FUNCTION
(as seen by DTE)
DCD
1
RD
2
R2IN
13
17
19
Received Data
Data Carrier Detect
TD
3
T1OUT
5
5
5
Transmitted Data
GND
4
4
4
DTR
4
SG
5
Data Terminal Ready
DSR
6
RTS
7
T2OUT
6
8
8
Request to Send (= DTE
ready)
CTS
8
R1IN
14
18
20
Clear to Send (= DCE ready)
RI
9
Signal Ground
Data Set Ready
Ring Indicator
Typical Application Circuit
+
2
VCC
TX
13
MAX3100
UART
RTS
CTS
R1OUT
RX
11
10
DB9
T1OUT
5
DI/T1IN
20
RO/R2OUT
10
DE/T2IN
12
14
HDPLX
R2IN
17
T2OUT
8
R1IN
MAX3161
19
9
18
1
SPI
GND
4
μP
RS-232
FAST
12
SHDN
Y(A)
7
Z(B)
6
RS-485
RJ45
RS-485/RS-232
SHDN
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Pin Configurations
TOP VIEW
+
+
+
C1+ 1
20 V+
C1+ 1
24 V+
C1+ 1
28 V+
VCC 2
19 C2+
VCC 2
23 C2+
VCC 2
27 C2+
C1- 3
18 C2-
C1- 3
22 C2-
C1- 3
26 C2-
21 V-
GND 4
25 V-
GND 4
Z(B)/T1OUT 5
GND 4
17 V-
MAX3160
Y(A)/T2OUT 6
16 DI/T1IN
15 DE485/T2IN
T1OUT 5
MAX3161
20 DI/T1IN
Z(B) 6
19 DE485/T2IN
24 T1IN
T1OUT 5
Z 6
MAX3162
23 DI
R1OUT 7
14 B/R1IN
Y(A) 7
18 R1IN
Y 7
RO/R2OUT 8
13 A/R2IN
T2OUT 8
17 R2IN
T2OUT 8
21 T2IN
SHDN 9
12 HDPLX
R1OUT 9
16 B
R1OUT 9
20 R1IN
FAST 10
11 RS-485/RS-232
RO/R2OUT 10
15 A
R2OUT 10
19 R2IN
20-PIN SSOP
SHDN 11
14 HDPLX
FAST 12
13 RS-485/RS-232
24-PIN SSOP
22 DE485
RO 11
18 B
RE485 12
17 A
SHDN 13
16 TE232
FAST 14
15 RE232
28-PIN SSOP
Selector Guide
PART
DUAL-MODE
FLOWTHROUGH
PIN-OUT
RS-485
INPUT UNIT
LOADS
MAX3160
No
Yes
1/4
MAX3161
No
No
1/8
MAX3162
Yes
Yes
1/8
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
20 SSOP
A20+1
21-0056
24 SSOP
A24+3
21-0056
28 SSOP
A28+3
21-0056
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+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
Revision History
REVISION
NUMBER
2
REVISION
DATE
12/09
DESCRIPTION
PAGES
CHANGED
Corrected the “Continuous Power Dissipation” specifications under the Absolute
Maximum Ratings.
2
Changed pin labels in the Functional Diagrams.
11
Deleted “TRANSISTOR COUNT: 1580” and added “PROCESS: BiCMOS” to the Chip
Information.
22
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
© Maxim Integrated
23
The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
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