Download QR/PSR CV/CC Controller BL8830A

BL8830A
QR/PSR CV/CC Controller
GENERAL DESCRIPTION
FEATURES
BL8830A is a high performance, highly integrated
QR (Quasi Resonant Mode) and Primary Side
Regulation (PSR) controller for offline small power
converter applications.
BL8830A has proprietary QR/PSR control for high
efficiency and low EMI. The IC can meet EPS Level
6 energy standard easily. The IC can support
“No-snubber & No-Y” design in 5W charger
applications. The IC also has built-in cable drop
compensation function, which can provide excellent
CV performance.
BL8830A integrates functions and protections of
Under Voltage Lockout (UVLO), VDD Over Voltage
Protection (VDD OVP), Output Over Voltage
Protection (Output OVP), Soft Start, Cycle-by-cycle
Current Limiting (OCP), Pin Floating Protection,
Gate Clamping, VDD Clamping.
BL8830A is available in SOT23-6 package.
◆ Easily Meet EPS Level 6
◆ Proprietary QR/PSR (Quasi-Resonant & Primary
Side Regulation) Control for High Efficiency and
Low EMI
◆ Support “No-Snubber & “No-Y” Design in 5W
(5V/1A) Charger Applications
◆ Less than 70mW Standby Power
◆ ±5% CC and CV Precision
◆ Proprietary Cable Drop Compensation
◆ Cycle-by-Cycle Current Limiting
◆ Built-in Leading Edge Blanking (LEB)
◆ Pin Floating Protection
◆ Built-in Soft Start
◆ Output Over Voltage Protection
◆ VDD OVP & Clamp
◆ VDD Under Voltage Lockout (UVLO)
APPLICATIONS
◆Battery chargers for cellular phones, cordless
phones, PDA, digital cameras, etc.
◆Replaces linear transformer and RCC SMPS
◆AC/DC LED lighting
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V1.0
BL8830A
QR/PSR CV/CC Controller
GENERAL INFORMATION
Pin Configuration
The pin map is shown as below for SOT23-6.
BL8830A is offered in SOT23-6 package.
GND
VD D
G A TE C O M P
CS
IN V
TERMINAL ASSIGNMENTS
Pin Num.
1
2
3
Pin Name
GND
GATE
CS
I/O
P
O
I
4
INV
O
5
6
COMP
VDD
I
P
Description
Ground
Totem-pole gate driver output to drive the external MOSFET.
Current sense pin.
System feedback pin. This control input regulates both the output
voltage in CV mode and output current in CC mode based on the
flyback voltage of the auxiliary winding.
Connect a capacitor between this pin and GND for CC regulation.
IC power supply pin.
OUTPUT POWER TABLE
Product
BL8830A
Universal Voltage
Adapter
18W
Package
Test Condition
SOT23-6
Indoor temperature 40℃
Absolute Maximum Ratings (Note 1)
Parameter
VDD DC Supply Voltage
VDD DC Clamp Current
GATE pin
COMP, CS voltage range
INV voltage range
Package Thermal Resistance (SOT-26)
Maximum Junction Temperature
Operating Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10sec.)
ESD Capability, HBM (Human Body Model)
ESD Capability, MM (Machine Model)
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Value
35
10
20
-0.3~7
-0.7~7
250
150
-40~85
-65~150
260
3
250
Unit
V
mA
V
V
V
℃/W
℃
℃
℃
℃
kV
V
V1.0
BL8830A
QR/PSR CV/CC Controller
Recommended Operation Conditions (Note 2)
Parameter
Supply Voltage, VDD
Operating Ambient Temperature
Maximum Switching Frequency
Value
10~30
-40~85
120k
Unit
V
℃
Hz
Note 1. 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.
Note 2. The device is not guaranteed to function outside its operating conditions.
BLOCK DIAGRAM
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V1.0
BL8830A
QR/PSR CV/CC Controller
ELECTRICAL CHARACTERISTICS
(TA=25℃, VDD=16V, if not otherwise noted)
Symbol
Parameter
Supply Voltage (VDD)
I_Startup
VDD Startup Current
I_VDD_Op
Operation Current
Test Conditions
Typ
Max
Unit
2
20
uA
0.65
1
mA
13.0
14.0
15.0
V
8.0
30
32
9.0
32
34
10.0
34
36
V
V
V
1.98
2.0
2.02
V
VDD=UVLO(ON)-1V,
Measure current into
VDD
VINV=1V,CL=0.5nF,
VDD=20V
VDD Under Voltage Lockout Exit
(Startup)
UVLO(OFF)
VDD Under Voltage Lockout Enter
VDD_OVP
VDD Over Voltage Protection trigger
VDD_Clamp
VDD Zener Clamp Voltage
Feedback Input Section(INV Pin)
Internal Error Amplifier(EA) reference
VINV_EA_Re
input
Output over voltage protection
VINV_OVP
threshold
VINV_Short
Output Short Circuit Threshold
FClamp_Short Output Short Circuit Frequency Clamp
Demagnetization comparator
VINV_DEM
threshold
Tmin_OFF
Minimum OFF time
Tmax_OFF
Maximum OFF time
ICable_max
Max Cable compensation current
Current Sense Input Section (CS Pin)
T_blanking
CS Input Leading Edge Blanking Time
Over Current Detection and Control
TD_OC
Delay
Constant Current Section (COMP Pin)
V_comp_ref
Internal CC reference
Gate Drive Output
VOL
Output Low Level
VOH
Output High Level
VG_Clamp
Output Clamp Voltage Level
T_r
Output Rising Time
T_f
Output Falling Time
UVLO(ON)
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Min
4/7
I(VDD)=7mA
CL=1nF at GATE
490
Io=20mA (sink)
Io=20mA (source)
VDD=24V
CL=0.5nF
CL=0.5nF
2.4
V
0.65
50
V
kHz
75
mV
2
2.8
40
us
ms
uA
500
ns
100
ns
500
7.5
16
700
35
510
mV
1
V
V
V
ns
ns
V1.0
BL8830A
QR/PSR CV/CC Controller
OPERATION DESCRIPTION
BL8830A is a high performance, multimode
controlled, highly integrated QR (Quasi Resonant)
Primary Side Regulation (PSR) controller. The
built-in high precision CV/CC control with high
level protection features make it very suitable for
offline small power converter applications.
◆ Startup Current and Startup Control
Startup current of BL8830A is designed to be very
low (typically 2uA) so that VDD could be charged
up above UVLO(ON) threshold level and device
starts up quickly. A large value startup resistor can
therefore be used to minimize the power loss yet
reliable startup in application.
◆ Operating Current
The operating current in BL8830A is as small as
0.65mA (typical). The small operating current
results in higher efficiency and reduces the VDD
hold-up capacitance requirement.
◆ QR/PSR Control
BL8830A uses a proprietary QR/PSR control for
high efficiency and low EMI. The IC works in
Quasi-Resonant (QR) mode in Constant Current
(CC) and Constant Voltage (CV) mode. In this way,
the efficiency is boosted and the EMI is reduced
greatly. The IC can easily meet EPS level 6
standard.
◆ Support “No-Snubber & No-Y” Design
with 600V Power MOSFET
BL8830A can support “No-snubber & No-Y”
design with normal 600V power MOSFET in 5W
(5V/1A) charger applications, which can reduce
the system cost greatly.
◆ Constant Current (CC) Regulation
I CC (mA) 
N 500(mV )

2 RCS ()
In the equation above,
N---- The turn ratio of primary side winding to
secondary side winding.
Rcs---- The sensing resistor connected between
the Source to GND.
◆ Precision CV/CC Performance
In BL8830A, the parameters are trimmed to tight
range, which makes the system CC/CV to have
less than 5% variation.
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◆ Soft Start
BL8830A features an internal soft start that slowly
increases the threshold of cycle-by-cycle current
limiting comparator during startup sequence. It
reduces the stress on the secondary diode during
startup. Every startup process is followed by a soft
start activation.
◆ Proprietary
Cable
Voltage
Drop
Compensation in CV Mode
When it comes to cellular phone charger
applications, the battery is located at the end of
cable, which causes typically several percentage
of voltage drop on the actual battery voltage.
BL8830A has a proprietary built-in cable voltage
drop compensation block which can provide a
constant output voltage at the end of the cable
over the entire load range in CV mode.
◆ Leading Edge Blanking (LEB)
Each time the power MOSFET is switched on, a
turn-on spike occurs across the sensing resistor.
To avoid premature termination of the switching
pulse, an internal leading edge blanking circuit
is built in. During this blanking period (500ns,
typical), the cycle-by-cycle current limiting
comparator is disabled and cannot switch off the
gate driver. Thus, external RC filter with a small
time constant is enough for current sensing.
◆ Minimum and Maximum OFF Time
In BL8830A, a minimum OFF time (typically 2us)
is implemented to suppress ringing when GATE is
off. The minimum OFF time is necessary in
applications where the transformer has a large
leakage inductance, particularly at low output
voltages or startup. The maximum OFF time in
BL8830A is typically 2.8ms, which provides a
large range for frequency reduction. In this way, a
low standby power of 70mW can be achieved.
◆ Output OVP(Over Voltage Protection) and
Output UVP (Under Voltage Protection)
In BL8830A, the output OVP is integrated by
plateau sampling the auxiliary winding in flyback
phase. The threshold voltage for output OVP is
2.4V, as shown in Fig.1 Output OVP is
auto-recovery mode protection (mentioned
below).
In BL8830A, when sensed INV voltage is below
0.65V, the IC will enter into Under Voltage
Protection (UVP) mode, in which the switching
frequency is clamped, as shown in Fig.1
V1.0
BL8830A
QR/PSR CV/CC Controller
◆ VDD OVP(Over Voltage Protection)
VDD OVP (Over Voltage Protection) is
implemented in BL8830A and it is a protection of
auto-recovery mode.
◆ Auto Recovery Mode Protection
Once a fault condition is detected, switching will
stop. This will cause VDD to fall because no power
is delivered form the auxiliary winding. When VDD
falls to UVLO(off) (typical 9.0V), the protection is
reset and the operating current reduces to the
startup current, which causes VDD to rise.
However, if the fault still exists, the system will
experience the above mentioned process. If the
fault has gone, the system resumes normal
operation. In this manner, the auto restart can
alternatively enable and disable the switching until
the fault condition is disappeared.
Fig.1
◆ Frequency Clamping @ Output Short
Circuit
In BL8830A, when INV voltage is below 0.65V, the
IC will enter into Under Voltage Protection (UVP)
mode, the switching frequency is fixed to 50KHz
(typical). This protection is useful for LED short
circuit protection. When output is short, the
frequency clamping can lower power MOSFET
Vds spike and the system reliability can be
improved.
In BL8830A, when output short circuit occurs, the
IC will fix the switching frequency to 50KHz. In this
way, the power MOSFET Vds spike voltage is
suppressed greatly.
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◆ Pin Floating Protection
In BL8830A, if pin floating situation occurs, the IC
is designed to have no damage to system.
◆ Soft Gate Drive
BL8830A has a soft totem-pole gate driver with
optimized EMI performance. An internal 16V
clamp is added for MOSFET gate protection at
higher than expected VDD input.
V1.0
BL8830A
QR/PSR CV/CC Controller
PACKAGE MECHANICAL DATA
SOT23-6L
Symbol
A
A1
A2
b
c
D
E
E1
e
e1
L
L1

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Dimensions in Millimeters
Min
Max
1.050
1.250
0.000
0.100
1.050
1.150
0.300
0.400
0.100
0.200
2.820
3.020
1.500
1.700
2.650
2.950
0.950TYP
1.800
2.000
0.300
0.600
0.300
0.600
0°
8°
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Dimensions in Inches
Min
Max
0.041
0.049
0.000
0.004
0.041
0.045
0.012
0.016
0.004
0.008
0.111
0.119
0.059
0.067
0.104
0.116
0.037TYP
0.071
0.079
0.012
0.024
0.012
0.024
0°
8°
V1.0