Download 1 Amp Plus to Minus Voltage Integrated Switching Regulator

TRUE RMS TO DC CONVERTER
Most current sensors produce outputs that are instantaneous representations
of the measured currents. For complex or ac waveshapes there may be a
requirement to convert the outputs to true rms values.
RMS converters available from Maxim are designed to accept complex
input waveforms containing ac and dc components. They can be operated from
either a single or dual supplies. The converters are designated MX536A/MX636.
Both devices draw less than 1 mA of quiescent supply current, making them ideal
for battery-powered applications. They exhibit >1MHz bandwidth and <.5% accuracy. (www.maxim-ic.com)
CREATE -12Vdc FROM +12Vdc
Texas Instrumentʼs PT78NR112 creates a negative output voltage from +12Vdc
input. These easy-to-use, 3-terminal, Integrated Switching Regulators have
maximum output power of 5 watts and a negative output voltage that is laser
trimmed. They also have excellent line and load regulation. They can be used
with current sensors that reguire ±12Vdc power supplies. (www.ti.com)
DEFINITIONS
Response Time
Response time is defined as the
delay between the instant the
sensed current reaches 90% of
its final value and the instant
the sensor output signal reaches
90% of final value as illustrated
in Figure 7. For open loop
sensors response time and di/dt
ratings depend primarily upon
the slew rate of the amplifier.
������� �������
���
����������
������
��
����
�������� ����
Figure 7
di/dt accurately followed
The linear rate of change in current that the sensor can accurately measure.
Linearity
Output deviation from a straight line response to the current being measured.
5
PT78NR100 Series
1 Amp Plus to Minus Voltage
Integrated Switching Regulator
SLTS058B
(Revised 8/31/2000)
•
•
•
•
•
•
Negative output from positive input
Wide Input Range
Self-Contained Inductor
Short Circuit Protection
Over-Temperature Protection
Fast Transient Response
Pin-Out Information
Standard Application
Vin
C1
1
PT78NR100
+
3
Function
1
+Vin
2
-Vout
3
GND
-Vout
2
C2
Pin
+
COM
COM
C1 = Required 100µF electrolytic (1)
C2 = Required 100µF electrolytic (1)
Specifications
Pkg Style 500
The PT78NR100 Series creates a
negative output voltage from a positive input voltage greater than 7V.
These easy-to-use, 3-terminal, Integrated Switching Regulators (ISRs)
have maximum output power of 5
watts and a negative output voltage
that is laser trimmed. They also have
excellent line and load regulation.
Ordering Information
PT78NR1 XX
Y
Output Voltage
Package Suffix
03 = -3.0 Volts
05 = -5.0 Volts
52 = -5.2 Volts
06 = -6.0 Volts
07 = -7.0 Volts
08 = -8.0 Volts
09 = -9.0 Volts
10 = -10.0 Volts
12 = -12.0 Volts
14 = -13.9 Volts
15 = -15.0 Volts
V = Vertical Mount
S = Surface Mount
H = Horizontal
Mount
PT78NR100 SERIES
Characteristics
(Ta= 25°C unless noted)
Symbols
Conditions
Output Current
Io
Over Vin range
Vo=-5V
Vo=-6V
Vo=-7, -8, -9V
Vo=-10V
Vo=-12V
Vo=-13.9, -15V
Min
Typ
Max
Units
0.05 (2)
0.05 (2)
0.05 (2)
0.05 (2)
0.05 (2)
0.05 (2)
—
—
—
—
—
—
1.00
0.8
0.55
0.5
0.40
0.30
A
Short Circuit Current
Isc
Vin=10V
—
4×Imax
—
Apk
Inrush Current
Iir
tir
Vin=10V
On start-up
—
—
4
0.5
—
—
A
mSec
Input Voltage Range
Vin
0.1 ≤ Io ≤ Imax
7
7
7
7
—
—
—
—
25
21
18
15
V
V
V
V
Output Voltage Tolerance
∆Vo
Over Vin range
Ta=-20°C to +70°C
—
±1.0
±3.0
%Vo
Line Regulation
Regline
Over Vin range
—
±0.5
±1.0
%Vo
Load Regulation
Regload
0.1 ≤ Io ≤ Imax
—
±0.5
±1.0
%Vo
Vo Ripple/Noise
Vn
Vin=10V, Io=Imax
—
±2
—
%Vo
Transient Response
(with 100µF output cap)
ttr
50% load change
Vo over/undershoot
—
—
100
5.0
250
—
µSec
%Vo
%
Vo=-5V
Vo=-6, -7, -8, -9V
Vo=-10, -12V
Vo=-13.9, -15V
Efficiency
η
Vin=10V, Io=0.5×Imax, Vo = -5V
—
75
—
Switching Frequency
ƒo
Over Vin and Io ranges
600
650
700
kHz
Absolute Maximum
Operating Temperaturte Range
Ta
Free Air Convection, (40-60LFM)
Over Vin Range
-40
—
+85 (3)
°C
Thermal Resistance
θja
Free Air Convection, (40-60LFM)
—
45
—
°C/W
Storage Temperature
Ts
—
-40
—
+125
°C
Mechanical Shock
—
Per Mil-STD-883D, Method 2002.3
—
500
—
G’s
Mechanical Vibration
—
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, soldered in a PC board
—
5
—
G’s
Weight
—
—
—
6.5
Grams
Notes: (1) The PT78NR100 Series requires a 100µF electrolytic or tantalum capacitor at both the input and output for proper operation in all applications. The input
capacitor, C1 must have a ripple current rating ≥600 mArms, and an ESR ≤0.2Ω.
(2) The ISR will operate down to no load with reduced specifications.
(3) See Thermal Derating chart.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
Typical Characteristics
PT78NR100 Series
1 Amp Plus to Minus Voltage
Integrated Switching Regulator
PT78NR105 -5.0 VDC
PT78NR109 -9.0 VDC
(See Note A)
Efficiency vs Output Current
100
90
90
90
Vin
7.0V
12.0V
15.0V
20.0V
25.0V
70
60
80
Efficiency - %
100
80
Vin
7.0V
70
12.0V
15.0V
18.0V
60
21.0V
50
(See Note A)
Efficiency vs Output Current
100
Efficiency - %
Efficiency - %
Efficiency vs Output Current
PT78NR112 -12.0 VDC
(See Note A)
VIN
80
7.0V
9.0V
12.0V
15.0V
18.0V
70
60
50
50
40
0
0.2
0.4
0.6
0.8
40
1
40
0
0.1
0.2
0.3
0.4
0.5
0
Ripple vs Output Current
160
200
VIN
21.0V
120
18.0V
15.0V
12.0V
80
7.0V
Ripple - mV
Ripple-(mV)
Vin
25.0V
20.0V
15.0V
12.0V
7.0V
80
0.4
250
Vin
120
0.3
Ripple vs Output Current
200
160
0.2
Iout-(Amps)
Ripple vs Output Current
200
Ripple-(mV)
0.1
Iout-(Amps)
Iout-(Amps)
18.0V
15.0V
12.0V
9.0V
7.0V
150
100
40
50
40
0
0
0.2
0.4
0.6
0.8
1
0
0
0
0.1
0.2
0.4
0
0.5
0.1
Thermal Derating (Ta)
(See Note B)
1
60°C
Thermal Derating (Ta)
(See Note B)
0.4
0.6
70°C
0.9
0.2
0.3
0.4
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Thermal Derating (Ta)
0.3
70°C
(See Note B)
70°C
0.35
0.5
0.8
85°C
0.6
0.5
0.4
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
0.3
0.7
0.4
85°C
0.3
0.2
0.3
0.25
85°C
0.2
0.15
0.1
0.2
0.1
0.1
0.05
0
0
7
10
13
16
19
22
25
0
7
11
15
Vin-(Volts)
19
7
10
13
Vin-(Volts)
Power Dissipation vs Output Current
Power Dissipation vs Output Current
2
1.6
1.8
1.4
16
19
Vin-(Volts)
Power Dissipation vs Output Current
1.6
1.4
1.6
1.2
Vin
20.0V
15.0V
1
12.0V
0.8
7.0V
1
21.0V
18.0V
1.2
0.8
15.0V
12.0V
0.6
7.0V
0.6
Pd - Watts
25.0V
1.2
Vin
PD-(Watts)
PD-(Watts)
1.4
VIN
18.0V
15.0V
12.0V
9.0V
7.0V
1
0.8
0.6
0.4
0.4
0.4
0.2
0.2
0.2
0
0
0
0.2
0.4
0.6
0.8
1
0
0.1
0.2
0.3
0.4
0.5
0
0
Iout-(Amps)
Iout-(Amps)
0.1
0.2
0.3
0.4
Iout-(Amps)
Note A: All data listed in the above graphs, except for derating data, has been developed from actual products tested at 25°C. This data is considered typical data for the ISR.
Note B: Thermal derating graphs are developed in free air convection cooling of 40-60 LFM. (See Thermal Application Notes.)
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
Customers are responsible for their applications using TI components.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright  2000, Texas Instruments Incorporated