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3232
WS
WS3232
WS3232 High PF PSR Constant Current LED Driver
Features
General Description
�
±5% LED Current Accuracy
�
Primary-side Sensing and Regulation Without
WS3232 is a high PF primary-side feedback and
regulation controller for LED lighting, optimized for flyback
TL431 and Opto-coupler
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No Auxiliary Winding For Sensing And Supplying
�
High Power Factor Correction
�
QR mode
�
600V MOS integrated
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Ultra low operating current
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LED Open/Short Circuit Protection
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CS Resistor Short Circuit Protection
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VCC over voltage protection & under voltage
converter with the output power less than 30W.
Since adopting primary sense and feedback control
technology, the secondary sense and feedback circuit is
eliminated. And WS3232 does not need the auxiliary
winding for sensing the output current and supplying the
chip. The low component counts and small system size
are realized.
Since using the high accurate current sense method,
WS3232 realizes ±5% accuracy of LED current along with
lockout( UVLO)
�
excellent line and load regulation.
Over Temperature Protection
WS3232
offers
comprehensive
protection
including
Cycle-by-Cycle current limiting (OCP), LED open/short
circuit protection, CS resistor short circuit protection, VCC
Applications
�
GU10 LED driver
�
LED spot light
�
Other LED lighting
UVLO,OVP and Clamp, and over temperature protection.
WS3232 is available in DIP-8 package.
Typical Application Circuit
NP
NS
AC
1 VCC
GND 8
2 NC
GND 7
3
COMP
4 CS
D 6
D 5
W/T-D036-Rev.A/0 Dec.2013
[email protected] Microelectronics Co., Ltd., All right r eserved.
1213
3232
WS
WS3232
Pin Definition and Device Marking
WS3232 is available inDIP-8 package:
NC
2
c om p 3
CS
4
8 GND
WS3232D8P
1
AXB YM
VC C
WS3232D8P:
A: 产品编码
7 GND
X:内部代码
6
D
B:地域代码
5
D
YM:年代码,月代码
Pin Function Description
Pin
Pin
Name
Number
VCC
1
Power Supply
NC
2
NC
Comp
3
Loop Compensation
CS
4
Current Sense
D
5/6
Drain
GND
7/8
Ground
Pin Type
Function Description
Power supply.
Floating
Loop compensation pin. Connect a RC network across this pin and
ground to stabilize the control loop.
Current sense. This pin connects a current sense resistor to GND to
detect the primary current of transformer.
Drain of Power MOS
Ground.
Block Diagram
VCC
B G &Internal
Power Supply
OVP
OT P
D
Tons
G a te
CC&L ogic Control
15V
9 .0 V 1 3 .8 V
0 .8 V
OCP
L in e
Compensation
CS
sampling
UVL O
G m 0 .5 V
RE SE T
0
C S*3*Tons/T
Tons
C om p
Valley、Tons
Detect
G a te
GND
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3232
WS
WS3232
Ordering Information
Package
IC Marking Information
Purchasing Device Name
DIP-8,
WS3232D8P
WS3232D8P
Pb-free
Recommended Operating Condition
Symbol
Parameter
Value
Unit
VCC
VCC supply voltage
9~14
V
TA
Operating temperature
-20~85
℃
Pout
Output power
<18
W
Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
Icc_max
VCC pin maximum sink current
5
mA
D
Drain of power MOS
-0.3~600
V
CS
CS pin input voltage
-0.3~7
V
Comp
Comp pin input voltage
-0.3~7
V
TJ
Operating junction temperature
-40~150
℃
TSTG
Min./Max. Storage temperature
-55~150
℃
Note
Note: Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These
are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated in the
Recommended Operating Conditions section are not implied. Exposure to absolute maximum-rated conditions for
extended periods may affect device reliability.
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3232
WS
WS3232
Electrical Characteristics (TA=25℃,VCC=14V, if not otherwise noted)
symbol
parameter
Test condition
Min
Typ
Max
Unit
Supply Voltage (VCC)
I_VCC_ST
Start up current
VCC=UVLO_ON-1V
60
100
uA
I_OP
Operation Current
Fop=7Khz
300
400
uA
UVLO_ON
Turn on threshold Voltage
VCC rising
12.7
V
UVLO_OFF
Turn-off threshold Voltage
VCC falling
10
V
VCC_Clamp
VCC Clamp voltage
Icc=5mA
15
V
500
ns
Current Sense Section
TLEB
Leading edge Blanking Time
V TH_OC
OCP threshold
Tdelay
Switch off delay time
485
500
515
mV
200
ns
Frequency Section
Ton_max
Max Primary On Time
24
us
Toff_max
Max Primary Off Time
224
us
Power MOS Section
Rds_on
ON-resistor
V GS=10V,ID=1.0A
Vds_BD
Breakdown voltage
ID=250μA
5
600
Ω
V
Over Temperature Protection
Tsd
Thermal shutdown threshold
150
℃
Tsd_hys
Thermal shutdown hysteresis
25
℃
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3232
WS
WS3232
Function Description
WS3232 is a high PF offline QR PSR controller, optimized
=(Vcs*Tons/T)*0.5*(Nps/Rcs)
for
=0.083*(Nps/Rcs)
low power
primary-side
LED driver. WS3232 operates
sensing and
in
regulation. Consequently,
Once the parameters of the transformer and the current
opto-coupler and TL431 could be eliminated, thus reduce
sense resistor Rcs is determined, so is the output current.
the cost.
And the output current can be set by adjusting the current
sense resistor Rcs.
Startup Current
Internal pre-charge design for quick start up
Startup current of WS3232 is designed to as low as 60uA.
The VCC capacitor will be charged through the start-up
After VCC exceeds UVLO_ON, Vcomp is pre-charged by
resistor when the system is powered on. Once the VCC
an internal current source. The PWM block will not start to
voltage reaches the start-up threshold, the WS3232 will
output PWM signals until Vcomp is over 0.45V. Such
start to switch. The WS3232 integrates a 15V zener for
design is meant to reduce the start up time. The voltage
VCC clamping. Due to the ultra-low operating current, the
pre-charged Vcomp in start-up procedure can be
auxiliary winding is not need to supply the IC.
programmed b y,
Vcomp=0.4V-300uA*Rcomp
Quasi-Resonant Operation
Where Rcomp is the series resistor of Comp pin.
Quasi-Resonant switching mode is applied in WS3232.
Operation switching frequency
When the voltage across drain and source of the primary
MOSFET is at voltage valley, the MOSFET would be
The frequency of WS3232 is decided by load condition
turned on, reducing the switching losses and improving
and QR mode. When the output power decreases, the
EMI performance.
switching frequency can become rather high. The
maximum switching frequency in WS3232 is internally
CC Operation
limited to 120Khz.
WS3232 is designed to produce good CC control
Current Sensing and Leading Edge Blanking
characteristic. In DCM mode, the output current Io can be
represented b y,
Cycle-by-Cycle current limiting is offered in WS3232. The
Io=0.5*Ips*Tons/T
switch current is detected by a sense resistor into the
Where Ips is the peak current of the secondary side; Tons
sense pin. An internal leading edge blanking circuit chops
is the turn on time of secondary side; T is the switching
off the sense voltage spike at initial MOSFET on state due
period.
to snubber diode reverse recovery so that the external RC
Ips=Ipp*Nps=(Vcs/Rcs)*Nps
filtering on sense input is no longer required. The current
Where Ipp is the primary peak current; Vcs is the voltage
limit comparator is disabled and thus cannot turn off the
on CS resistor; Rcs is primary current detection resistor;
external MOSFET during the blanking period.
Nps is the turns ratio of primary to secondary of the
flyback transformer. The relationship of Vcs, To ns and T is
controlled
to
be
constant
by
internal
circuit,
3*Vcs*Tons/T=0.5V. Thus, Io can be represented b y,
Io=0.5*(Vcs/Rcs)*Nps*Tons/T
Protection Controls
Excellent
system
stability
is
achieved
by
the
comprehensive protection of WS3232. Including
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3232
WS
WS3232
Cycle-by-Cycle current limiting (OCP), LED open/short
the system will recover to normal operation.
circuit protection, CS resistor short circuit protection, VCC
The thermal shutdown circuitry in the WS3232 senses the
UVLO,OVP and Clamp, over temperature protection, and
die temperature after start up, and the thermal protection
so on.
threshold is set to 150℃ with a 25℃ hysteresis. When the
When the LED is open circuit, it will trigger over-voltage
temperature on die of WS3232 rises and reaches the
protection logic and latch, the system stops switching
threshold, the power MOSFET will be shut down
immediately; When the LED short circuit is detected, the
immediately
system works at low frequency(Fop=5Khz), so the power
temperature on die falls 25℃ from thermal protection
loss is low. At some catastrophic fault condition, such as
trigger point.
and
maintained
switch
off
until
the
shorted CS resistor or flyback transformer saturation, the
internal fast fault detection circuit will trigger and latch, the
system stops switching immediately.
After the system enters into fault latch condition, the VCC
voltage will fall until it reaches UVLO threshold. Then the
system will re-start again. If the fault condition is removed,
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3232
WS
WS3232
Package Information
DIP-8 Package Outline Dimensions
D2
θ2
C1
C
C4
θ1
C2
C3
θ3
A2
A5
A1
D1
A3
D
A4
B
A
Winsemi
Symbol
Dimensions in Millimeters
Dimensions in Inches
Min
Max
Min
Max
A
9.00
9.50
0.354
0.374
B
6.10
6.60
0.240
0.260
C
3.0
3.4
0.118
0.134
A1
1.474
1.574
0.058
0.062
A2
0.41
0.53
0.016
0.021
A3
2.44
2.64
0.096
0.104
A4
0.51TYP
0.02TYP
A5
0.99TYP
0.04TYP
C1
6.6
C2
7.30
0.260
0.50TYP
0.287
0.02TYP
C3
3.00
3.40
0.118
0.134
C4
1.47
1.65
0.058
0.065
D
7.62
9.3
0.300
0.366
D1
0.24
0.32
0.009
0.013
D2
7.62TYP
0.3TYP
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