EC4329 [E-CMOS]
Offiline Step-down Buck LED Driver IC with APFC;
| 型号： | EC4329 |
| 厂家： | 
E-CMOS Corporation |
| 描述： | Offiline Step-down Buck LED Driver IC with APFC 功率因数校正 |
| 文件： | 总7页 (文件大小：554K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Offiline Step-down Buck LED Driver IC with APFC
EC4329
General Description
Features
High Power Factor, ultra- low THD
The EC4329 is a high precision non-isolated buck driver
with APFC, specially designed for universal input offline
constant current LED lighting, and reach out low THD.
Operating in critical conduction mode, the power MOSFET
switching loss is reduced and the inductor is fully utilized.
Withthe fewest external components, and cutting- edge
circuit design, output ability can be precisely controlled in
the most competitive method of all kinds.
Valley Switch, High Efficiency, LOW EMI
Soft Start
Thermal Regulation Compensation
±3% Output Current Accuracy
Universal AC input
Auto Induction Compensate
Auto Output Voltage adaption
Full Protection Features: ( LED O/S CKT; OTP
OCP; OVP/UVP)
EC4329 adopts floating ground structure, inductor current
is hence sensed during the whole switching cycle, which
generates precise output current, line and load regulation
when being applied in system.
Auto Recovery to default
Fewest external components required on board
Applications
EC4329 also features full protection function to enhance
Reliability on board, including LED Open/ Short circuit
Protection, OVP/ UVP/ OTP( Self- reduce)/ OCP Current
Sensing Open protection, Soft start and so on.
LED High Brightness Lighting
Light Bulb, Light Tube
EC4329 performed in compact SOT23-6 package.
Typical Application
E-CMOS Corp. (www.ecmos.com.tw)
Page 1 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
Pin Configuration
EC4329 performed in SOT23-6 Package shown as below：
Pin Definition
Pin Name
Pin #
Feature Description
VCC
1
Chip Power supply pPin
Ground Pin of Chip
GND
COMP
GATE
CS
2
3
4
5
6
Loop Compensation node
Driving Pin to the external Power MOSFET( Gate )
Current Sensing Pin. Connect a resistor to GND
Feedback Voltage Input Pin
FB
Ordering Information
EC4329 NN XX X
R : Tape Reel
B2：SOT23-6L
Part No.
Package type
SOT23-6L
Marking
Remark
4329
LLLL
EC4329NNB3R
1. LLLL：LOT NO.
E-CMOS Corp. (www.ecmos.com.tw)
Page 2 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
Block Diagram
Absolute Maximun Rating（ Note 1）
Symbol
Parameter
Range
Unit
VCC
Input Voltage
-0.3~8.5
V
V
VCS
VFB
Current Sensing Pin input Voltage
Feedback Pin Input Voltage
Compensation Pin Voltage
Power Dissipation（Note 2）
Maximum Junction Temperature
Storage Temperature
-0.3~7
-0.3~7
-0.3~7
0.25
V
VCOMP
PDMAX
TJ
V
W
℃
℃
160
TSTG
-55~150
Note 1: Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. Under
“recommended operating conditions” the device operation is assured, but some particular parameter may not be achieved. The
electrical characteristics table defines the operation range of the device, the electrical characteristics is assured on DC and AC
voltage by test program. For the parameters without minimum and maximum value in the EC table, the typical value defines the
operation range, the accuracy is not guaranteed by spec
Note 2: The maximum power dissipation decrease if temperature rise, it is decided by TJMAX, θJA, and environment temperature (TA).
The maximum power dissipation is the lower one between
PDMAX = (TJMAX - TA)/ θJA and the number listed in the maximum table. Parameter shown in column is not including external
Power MOSFET.
Recommended Operating Condition
Parameter
Vcc Voltage
Operating Temperature
Range
7.5~8.5
-20~85
Unit
V
℃
VCC
TA
E-CMOS Corp. (www.ecmos.com.tw)
Page 3 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
Electrical Characteristics (Unless otherwise specified, VCC=8V and TA =25 ℃ )
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
Supply Voltage Section
8.5
Vcc_clamp VCC clamp Voltage
Icc_clamp VCC clamp Current
7.5
8.0
V
mA
V
5
VCC_ST
Start-up Voltage
VCC rising
7.07
7.57
1.32
8.07
Vuvlo_HYS UVLO Hysteresis Voltage
VCC falling
V
70
Ist
Start-up Current
VCC<VCC_ST-0.5V
100
600
uA
uA
Iop
Operating Current
400
Current Sensing Section
OCP Peak Voltage Limitation
Vocp
TLEB
Td
1
V
Leading Edge Blanking Time
for Current Sense
350
200
ns
ns
Switch off Delay Time
Compensation Section
Internal Driving Section
Feedback Section
VREF
VCL
Internal Reference Voltage
COMP Low Clamp Voltage
COMP High Clamp Voltage
194
200
1.5
4.0
206
mV
V
VCH
V
TOFF_MIN Minimum Off Time
TON_MAX Maximum On Time
TOFF_Max Maximum Off Time
3
us
us
us
20
100
FB Over Voltage Protection
VFB
1.6
0.2
V
V
FB Falling Edge Threshold
Voltage
VZCD
Over Temp. Protection Section
℃
℃
℃
Tcomp
TSD
Thermal regulation Temp.
OTP Shut Down Temp.
150
160
30
TSD_HYS Shut Down Hysteresis Temp.
E-CMOS Corp. (www.ecmos.com.tw)
Page 4 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
Application Info.
Output Current control
The EC4329 utilizes floating ground structure. The inductor
current is sensed during the whole switching cycle, hence it
achieves high precision output current and perfect line and
load regulation. The current in LED can be calculated by
equation of:
EC4329 is a high precision Active PFC driver which
specifically designed for non-isolated buck offline constant
current LED lighting. Even when switching in critical
conduction condition, EC4329 achieves high power factor,
high efficiency and ultra- low THD.
Start- up
Where 200mV is the internal reference voltage, and Rcs is
the value of current- sensing resistor.
With ultra- low start- up power( Typ.@70uA, Max. @
100uA）， when it is applied at Vac = 85V to start- up，the
start- up Resistance can be calculated in below ：
Feedback Voltage measurement (OVP)
Voltage on FB pin determines operating state on board ，
when it reaches over 1.6V(Typ.) , EC4318 would sense
and turn into Over- Voltage Protection mode， and system
is thus jump to power- saving “ hiccup mode” ， OVP
voltage is generated by：
Chip Power supply and consumption
After EC4318 being started-up，the rectifier D6 is crucial
to adopt fast recovery Diode. The formula of Current- limit
resistance R4 would be：
Please refer to typical application schematic to find R2 &
R3, in which R3=10K,（15K Max., and 8.2K Min.），in
above formula, the Constant 1.6 can be put 1.3 when
designing systems, Set Vovp= 90V, we can come out
R2=552K from above equation, herewith, we adopt 560K
resistor instead. As VFB is between 1.3-1.9, when
choosing the withstand voltage of C4, It is recommended to
set @ 1.9，hence, Vovp =1.9*（10+560）/10 =108V，
moreover, the Withstand Voltage of C4 must be over
Vovp，herein We choose C4 @ 200V. After EC4329 falls
in “hiccup mode”, the output voltage is automatically
sensed constantly in working cycles. When output voltage
is beneath Vovp, system would recover to normal function
state.
In which “D” stands for duty Cycle，and 400uA is normal
operating current of EC4329 ， VLED is output loading
voltage. Power consumption of this certain Resistor can be
calculated at：
For instance：when Solution requires：
Vac in= 180~260V，Vout= 36~80V，Iout= 240mA Then,
in low range of Vac in=180V; Vout =36V => R4 could be
generated in the following calculation:
D=36/180/1.414=0.141, R4=(1-0.141)*(36-9)/400uA=58K;
In high range of Vac in= 260V，Vout= 80V，then
D=80/260/1.414=0.218，and the power consumption
of resistance is：
P=（80-9）*（80-9）/58 * (1-0.218)=68 mW。
E-CMOS Corp. (www.ecmos.com.tw)
Page 5 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
LED Open/ Short Protection
The Area of Power Loop
When the LED is open circuit, the output voltage will
gradually rise up. The output voltage is sensed by the FB
pin when power MOSFET is turned off. When FB voltage
reaches the OVP threshold, it will trigger fault logic and the
system stops switching. When the LED is shorted circuit,
the system will work under 10kHz switching frequency.
Meanwhile, the output voltage is low and the VCC pin
cannot be charged up by the output voltage, so the VCC pin
voltage will gradually decrease and finally reaches the
UVLO threshold.
The area of main current loop should be as small as
possible to reduce EMI radiation.
FB Pin
The feedback resistor divider should be as close as
possible to the FB pin, and the trace must keeps away from
dynamic node of the inductor (DRAIN Pin trace), otherwise
the FB pin OVP function might have risk to be mis-
triggered by noise in system.
DRAIN Pin
Thermal Regulation (Over Temp. Protection)
The EC4329 integrates thermal regulation function. When
the system is over 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 regulation temperature is set to 150℃ internally.
To increase the copper area of DRAIN pin for better
thermal dissipation. However, over- enlarged copper pad
might also compromise EMI performance. Please leverage.
Filtering input Capacitor
With purposes to gain higher power factor, this Cap. Is
suggested to set @ 10-100nF
PCB Layouts
The following guidelines is recommended in EC4329 PCB
layout:
Bypass Capacitor:
The bypass capacitor on VCC pin should be as close as
possible to the VCC and GND pins.
Ground Path:
The power ground path for current sense resistor should
be short and wide, and it should be as close as possible to
the IC ground pins, otherwise the LED output current
accuracy may be affected. The IC signal ground for COMP
and FB components should be connected to the IC GND
pins with short traces, and should be away from the power
ground path.
E-CMOS Corp. (www.ecmos.com.tw)
Page 6 of 7
4I04N-Rev.F001
Offiline Step- down Buck LED Driver IC with APFC
EC4329
Package Information
E-CMOS Corp. (www.ecmos.com.tw)
Page 7 of 7
4I04N-Rev.F001
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