20160401090541 4514

WS9822B Product Description
Non-isolated Buck High Precision Three-stage Dimming LED Driver
Features
Description

Three-stage switcher dimming: 100%-40%-15%
The WS9822B is a three-stage dimming constant current

Compatible PCB with WS3442
LED driver with high precision and is applied to non-isolated

Internal 500V Power MOSFET
buck LED power system. The WS9822B integrates a switch

Critical Conduction Mode Operation
dimming circuit and can change the output current through

±3% LED Current Accuracy
switch shifting.

without Auxiliary Winding for power supplying

Efficiency up to 93%
suitable for universal input offline LED lighting to dim with

LED Open and Short Circuit Protection
three-stage by switcher.

Thermal Regulation Function to avoid lights flicking
The device operates in critical conduction mode and is
under high temperature.
The WS9822B utilizes proprietary current control method.
It can achieve precise LED output current and excellent line
regulation.
The operating current of the IC is as low as 120uA. So it
doesn’t need the auxiliary winding for supplying the chip,
which brings more simplified designs and lower cost.
The WS9822B adopts intelligent temperature control and
thoroughly solves the problem of LED flickering under high
Typical Applictions
temperature.

T5/T8 LED Strings

Ceiling Lamps

Bulbs
protection, LED short circuit protection, and VCC under

Other LED Lightings
voltage protection.
The WS9822B offers multiple protection functions to
improve the system reliability, including LED open circuit
Typical Application Circuit
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
[email protected] Microelectronics Co., Ltd., All right
reserved.
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
0121
WS9822B Product Description
Pin Definition and Device Marking
WS9822B is available in DIP-7 and SOP-7 packages:
WS9822BD7P:Product Code
A:Product Code
X:Internal Code
BCY:Internal QC Code
YMX:D/C
WS9822BS7P:Product Code
A:Product Code
X:Internal Code
BCY:Internal QC Code
YMX:D/C
Package Pin Definition
Pin name
Pin No.
1
GND
2
ROVP
3
NC
4
VCC
Power Supply Pin
5/6
Drain
Internal HV Power MOSFET Drain.
7
CS
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
Desciption
Ground
Over Voltage Protection Setting Pin. Connect a resistor to GND.
No connection, must be floated.
Current Sense Pin. Connect a sensing resistor between this pin and GND pin.
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
2/11
WS9822B Product Description
Internal Block Diagram
Ordering Information
Package
Marking
Part Number
7-Pin DIP-7, Pb-free
WS9822BD7P
WS9822BD7P
7-Pin SOP-7, Pb-free
WS9822BS7P
WS9822BS7P
Recommended Operation Conditions
Part Number
Maximum output
Package
Input voltage
DIP7
175VAC-264VAC
28W
SOP7
175VAC-264VAC
24W
power
WS9822B
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
3/11
WS9822B Product Description
Absolute Maximum Ratings
Symbol
Parameter
Limit
Unit
VD
Internal HV MOSFET drain voltage
-0.3~500
V
ICC_MAX
Maximum sink current
20
mA
-0.3~7
V
LED open circuit protection voltage
VROVP
regulation
VCS
Current sense pin input voltage
-0.3~7
V
PDMAX
Power dissipation (note 2)
0.9
W
TJ
Maximum operating junction temperature
165
℃
TSTG
Minimum/Maximum Storage temperature
-55~165
℃
Note 1:Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device.
Note 2: The value of power dissipation is closely related to the heat emission conditions. The values in the table above are
measured on the test board without heat sink and case, and Ta<40℃.
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
4/11
WS9822B Product Description
Electrical Characteristics
Conditions: TA=25℃,VCC=14V(Unless otherwise specified)
Symbol
Parameter
Test condition
Min
Typ
Max
Unit
Power Supply Section
VCC_CLAMP
VCC Clamp Voltage
ICC_CLAMP
VCC Clamp Current
UVLO_OFF
Chip Startup Voltage
Under voltage
UVLO_ON _HYS
Protection Hysteresis
IST
Startup Current
IOP
Operating Current
IVCC=1mA
16
5
V
20
mA
VCC Rising
15.8
V
VCC Falling
3.5
V
VCC=UVLO_off-0.5V
65
130
195
uA
120
uA
400
mV
114
mV
350
ns
200
ns
Current Detection Section
VCS_TH
Threshold Voltage for Peak
Current Limitation
Threshold Value for
VCS_DIM
Dimming Test
Leading Edge Blanking Time
TLEB
for Current Sense
TDELAY
Switch Off Delay Time
Switching Frequency Section
TOFF_MIN
Minimum OFF Time
3
us
TOFF_MAX
Maximum OFF Time
240
us
TON_MAX
Maximum On Time
40
us
VROVP
ROVP PIN Voltage
0.5
V
Shutdown Reset Time
5
S
DIM Dimming Section
TRESET
MOSFET Section
Power MOSFET Drain
IDSS
Leakage Current
BVDSS
RDS_ON
VGS=0V,VDS=500V
Drain-Source Breakdown
10
500
Voltage
Static Drain-source
V
4.8
On-state resistance
uA
6
Ω
Thermal section
Thermal Regulation
TREG
WINSEMI
150
Temperature
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
℃
WINSEMI
MICROELECTRONICS
5/11
WS9822B Product Description
Function Description
winding is not needed to supply the IC.
VCC Capacitor Selection
The WS9822B is a three-stage dimming constant
current LED driver with high precision and is applied to
The Vcc capacitor is used to bypass noise to IC, so that
non-isolated buck LED power system. The WS9822B
to assure its stable operation, and should be as close as
integrates a switcher dimming circuit and can change the
possible to the chip.
output current through shifting external switcher ON/OFF to
A 4.7uF/25V electrolytic capacitor can be used to Vcc Pin.
perform the dimming function.
If selecting MLCC, the material of X7R will be used to satisfy
The WS9822B is compatible the PCB board with
the stability of the capacity under high temperature. Due to
mainstream non-dimming products in the markets, such as
external damage resulted from small volume and brittle texture
WS3442, thus it can achieve the seamless upgrades from
of MLCC, it is easy to cause Vcc currents leakage, which will
non-dimming to ON/OFF dimming.
make the WS9822B unable to start. Strict control measures
are taken in the layout and productive process.
Switcher Dimming Control
In order to avoid the return flickering and the disorder time,
The switcher is opened first and closed again when the
the Vcc capacitor should be in parallel with discharge resistor,
dimming is required, and the output current changes in
which value should be chosen from 150KΩ to 240KΩ.
accordance with the presetted current. The switching time
Constant Current Control
should be more than 500mS. The dimming current cyclically
varies in the sequence of 100% to 40% to15%. The reset
Utilizing
proprietary
current
control
method,
the
time is 5S. So it is a normal dimming if the time interval of the
WS9822B can achieve precise LED output current with a few
switch from turn-off to turn-on is less than 5s; otherwise it will
external components. Cycle by Cycle current sense is adopted
be considered as a reset signal. The output current reaches
in WS9822B, the CS pin is connected to the current sense
up to 100% after the switch is on again whatever the output
comparator, and the voltage on CS pin is compared with the
stage of the preceding current is.
internal 400mV reference voltage. The MOSFET will be
switched off when the voltage on CS pin reaches the threshold.
Start Up
The CS comparator includes a 350ns leading edge blanking
The VCC capacitor will be charged through the start-up
time.
The peak inductor current is calculated by the equation
resistor when the system is powered on. When the VCC pin
(2):
voltage reaches the turn on threshold, the internal circuits
I PK 
start operating. The WS9822B integrates the 16V ZENER for
clamping the VCC.
The typical value of the start-up current is 130uA (the
The current in LED can be calculated by the equation(3)
:
264VAC, the start-up resistor can be calculated by the
equation(1):
Rst 
I st _ max
(2)
Where, RCS is the current sense resistor value.
maximum value is 195 uA). For the application of 176VAC—
Vin _ min  1.414
0.4
(mA)
Rcs
176V  1.414

 1.27M (1)
195uA
I LED 
I PK
(mA)
2
(3)
Where, IPK is the peak current of the inductor.
The start-up resistor can be chosen from 720K Ω to
1.2MΩ. Two resistors in 1206 size SMD or 1/4W metal film
resistors can be used in series.
The diode will bear the reverse voltage equal to the
Due to the ultra-low operating current, the auxiliary
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
Freewheeling Diode
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
input voltage when the MOSFET is on. A 600V diode was
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
6/11
WS9822B Product Description
suggested to use. Besides, the operating frequency of
t off 
freewheeling diode is from 20K to 120 KHz, such ultra fast
recovery diodes as ES and ER whose Trr is less than 50ns
L
Input voltage should be considered in to the capacitor
(5)
The inductance can be calculated by the equation(6):
are good choice.
Input Buck Electrolytic Capacitor
L  I PK
V LED
V LED  (V IN  V LED )
f  I PK  V IN
(6)
Where, f is the maximum system switching frequency,
which is proportional to the input voltage. So the minimum
pressure, and the common value is 400V.
In general, the capacitor design can be calculated by the
switching frequency is set at lowest input voltage, and the
maximum switching frequency is set at highest input voltage.
following empirical equations:
90Vac~264Vac: 1W output uses1uF intput electrolytic
The minimum and maximum off time of WS9822B is set
at 3us and 240us respectively. Referring to the equation of Toff
capacitor;
176Vac~264Vac:
1W
output
uses
0.5uF
intput
calculation, if the inductance is too small, the Toff may be
smaller than the minimum off time, the system will operate in
electrolytic capacitor.
discontinuous conduction mode and the output current will be
Output Capacitor
smaller than the designed value. If the inductance is too large,
Electrolytic capacitor is recommended to be used. Its
the Toff may be larger than the maximum off time, the system
stable capacitance can improve the efficiency of power
will operate in continuous conduction mode and the output
supply, the LED ripple current and luminous efficiency.
current will be higher than the designed value. So it is
Vovp voltage should be considered in output capacitor
important to choose a proper inductance.
In addition, the OVP voltage changes with the Inductance
pressure.
value. Due to open magnetic flux of DR core, the Inductance
Inductor Selection
value changes easily under the influence of temperature and
The WS9822B works under inductor current critical
external environment. Therefore, please don’t use them along
conduction mode. When the power MOFET is switched on,
with the product in order to prevent from false triggering of
the current in the inductor rises up from zero. The on time of
OVP.
the MOSFET can be calculated by the equation (4):
t on 
Over Voltage Protection
L  I PK
V IN  V LED
(4)
The over voltage protection of the WS9822B can be
programmed by the ROVP pin resistor. The voltage of ROVP
Where,
pin is 0.5V.
L is the inductance value,
When the LED is open circuit, the period of the output
IPK is the peak current of the inductor,
VIN is the DC bus voltage after the rectifier bridge,
voltage increases gradually, the demagnetization time gets
shorter. The demagnetization time at OVP---- Tovp can be
VLED is the voltage on the LED.
After the power MOSFET is switched off and the current
in the inductor decreases. When the inductor current reaches
zero, the power MOSFET is turned on again by IC internal
calculated by the open circuit protection voltage by the
equation (7):
TOVP 
logic. The off time of the MOSFET is given by the equation
L  VCS
RCS  VOVP
(7)
Where,
(5):
Vcs is the CS pin turn off threshold (400mV);
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
7/11
WS9822B Product Description
Vovp is the open circuit protection voltage.
At some abnormal fault condition, such as CS resistor
And then the Rovp resistor value can be calculated by the
equation (8):
shorted or inductor saturation, the internal fast fault detection
circuit
ROVP  5  TOVP  10 6
( K )
will
be
triggered,
the
system
stops
switching
immediately.
(8)
After the system enters into faulty condition, the VCC
In normal application, the value of Tovp cannot be lower
than 4us, or in other words, the value of Rovp cannot be
lower than 20K, with its recommended range from 20K to
voltage will decrease until it reaches the UVLO threshold, then
the system will restart again. If the fault condition is removed,
the system will recover to normal operation.
50K. The resistance of Rovp with 1% accuracy should be
used to assure the accuracy of OVP.
PCB Layout
Line Voltage Compensation
The following rules should be followed in WS9822B PCB
The WS9822B integrates line voltage compensation
function, which makes LED current remain unchanged in the
range of full voltage, thus has good line regulation and
current accuracy.
layout:
VCC Capacitor: The VCC capacitor should be as close
as possible to the VCC Pin and GND pin.
Ground Path: The power ground path for current sense
resistor should be as short as possible, and the power ground
Thermal Regulation
The WS9822B integrates thermal regulation function.
When the system is under higher temperature, the output
current is gradually reduced; the output power and thermal
dissipation are also reduced. The system temperature is
regulated and the system reliability is improved. The thermal
path should be separated from small signal ground path
before connecting to the negative node of the bulk capacitor.
The Area of Power Loop: The area of main current loop
should be as small as possible to reduce EMI radiation, and it
should be away from diodes and other heating components.
DRAIN PIN: The copper area of DRAIN pin can be
regulation temperature is set at 150℃ internally.
increased for better thermal dissipation. And it should be away
Protection Function
from CS / VCC and ROVP Pin.
The WS9822B offers full protection functions to improve
the system reliability, including LED open/short protection,
ROVP PIN: The ROVP resistor should be as close as
possible to the ROVP Pin to prevent from the interference.
CS resistor short protection, VCC under voltage protection,
The material of PCB: Avoid choosing the material that is
thermal regulation. When the LED is open circuit, the system
easy to absorb the moisture, just like paper copper-clad
will trigger the over voltage protection and stop switching.
laminates.
When the LED short circuit is detected, the system works at
lowest frequency. So the system power consumption is very
low.
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
8/11
WS9822B Product Description
DIP7 Package Dimension
Winsemi
Dimensions in Millimeters
Symbol
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
WINSEMI
Dimensions in Inches
7.62TYP
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
0.3TYP
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
9/11
WS9822B Product Description
SOP7 Package Dimension
Winsemi
Dimensions in Millimeters
Symbol
Dimensions in Inches
Min
Max
Min
Max
A
4.70
5.10
0.185
0.201
B
3.70
4.10
0.146
0.161
C
1.30
1.50
0.051
0.059
A1
0.35
0.48
0.014
0.019
A2
1.27TYP
0.05TYP
A3
0.345TYP
0.014TYP
B1
5.80
B2
6.20
0.228
5.00TYP
0.244
0.197TYP
C1
0.55
0.70
0.022
0.028
C2
0.55
0.70
0.022
0.028
C3
0.05
0.225
0.002
0.009
C4
0.203TYP
0.008TYP
D
1.05TYP
0.041TYP
D1
WINSEMI
0.40
MICROELECTRONICS
www.winsemi.com
WINSEMI
0.80
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
0.016
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
0.031
WINSEMI
MICROELECTRONICS
10/11
WS9822B Product Description
NOTE:
1.We strongly recommend customers check carefully on the trademark when buying our product, if there is any
question, please don't be hesitate to contact us.
2.Please do not exceed the absolute maximum ratings of the device when circuit designing.
3.Winsemi Microelectronics Co., Ltd reserved the right to make changes in this specification sheet and is
subject to change without prior notice.
CONTACT:
Winsemi Microelectronics Co., Ltd.
ADD:Room 1002, East, Phase 2, HighTech Plaza,Tian-An Cyber Park,Chegongmiao, FuTian, Shenzhen, P.R.
China
Post Code : 518040
Tel : +86-755-8250 6288
FAX : +86-755-8250 6299
Web Site : www.winsemi.com
WINSEMI
MICROELECTRONICS
www.winsemi.com
WINSEMI
MICROELECTRONICS
Tel : +86-755-8250 6288
WINSEMI
MICROELECTRONICS
Fax : +86-755-8250 6299
WINSEMI
MICROELECTRONICS
WINSEMI
MICROELECTRONICS
11/11