Lighting Driver. HT7L4811 Datasheet

HT7L4811 Driver. Datasheet pdf. Equivalent

HT7L4811 Datasheet
Recommendation HT7L4811 Datasheet
Part HT7L4811
Description Non-isolation Buck LED Lighting Driver
Feature HT7L4811; HT7L4811 Non-isolation Buck LED Lighting Driver with Active PFC Features • Tiny package SOT23-6 • .
Manufacture Holtek Semiconductor
Datasheet
Download HT7L4811 Datasheet




Holtek Semiconductor HT7L4811
HT7L4811
Non-isolation Buck LED
Lighting Driver with Active PFC
Features
• Tiny package SOT23-6
• Non-isolation buck topology
• Low BOM Cost
• Wide AC input range – from 85VAC to 265VAC
• High Power Factor of >0.9 without additional
circuitry
• Accurate constant current (< ±3%)
• Low start-up current which reduces power
dissipation
• Full protection functions for enhanced safety
Gate driver output voltage clamp
VCC over voltage protection (VCC OVP)
VCC under-voltage lockout with hysteresis
(VCC UVLO)
Output LED string over current protection
Output LED string short protection
Output LED string open protection
On-chip over temperature protection (OTP)
Applications
• General illumination
• E26/27, T5/T8 LED Lamp
• Other LED Lighting Applications
General Description
The HT7L4811 is a non-isolation buck PWM controller
for LED lighting applications. The device has a fully
integrated PFC circuit which operates in a boundary
conduction mode (BCM) to achieve high power factor
values. With good control over external MOSFETs, the
device can easily meet exacting LED current and high
power factor requirements.
The HT7L4811 provides several protection functions,
which include VCC Under Voltage Lockout (UVLO),
Over Current Protection (OCP), Output LED
String Open Protection, Output LED String Short
Protection, VCC Over Voltage Protection (OVP) and
Leading-Edge Blanking (LEB) for current sensing.
Additionally and to ensure system reliability, the
device includes a fully integrated thermal protection
function. To protect the external power MOSFET
from being damaged by a supply over voltage, the
device DRV pin voltage is clamped to about 17V.
The high level of functional integration minimises the
external component count giving major advantages
in terms of cost and circuit board area. The device is
supplied in a SOT23-6 package.
Rev. 1.30
1 June 26, 2015



Holtek Semiconductor HT7L4811
Block Diagram
VCC
UVLO
ZCD
VCC OVP
ZCD OVP
Reference
& Bias
Min
Off Time
ZCD
Comparator
OTP
OCP
CS
0.2V
EA
Starter
PWM
Generator
COMP
Pin Assignment
SOT23-6
COMP CS ZCD
HT7L4811
DRV
Driver
Logic
Control
LEB
GND
L4811 Top View
VCC GND DRV
Pin Description
Pin No.
1
2
3
4
5
6
Symbol
VCC
GND
DRV
ZCD
CS
COMP
Description
Power supply pin
Ground pin
Gate drive output for driving external power MOSFETs
Zero-current detect pin
Current sense pin. A resistor is connected to sense the MOSFET current.
Loop compensation pin. A capacitor is placed between COMP and GND.
Rev. 1.30
2 June 26, 2015



Holtek Semiconductor HT7L4811
HT7L4811
Absolute Maximum Ratings
VCC supply voltage................................ -0.3V to 33V
Input voltage to CS pin.............................. -0.3V to 6V
Output voltage at COMP pin..................... -0.3V to 6V
Maximum current at ZCD pin................3mA (source),
3mA (sink)
Maximum operating junction temperature......... 150°C
Storage temperature range................... -55°C to 150°C
Note: These are stress ratings only. Stresses exceeding the range specified under ″Absolute Maximum Ratings″
may cause substantial damage to the device. Functional operation of this device at other conditions beyond
those listed in the specification is not implied and prolonged exposure to extreme conditions may affect
device reliability.
Recommended Operating Ranges
VCC supply voltage...................................17V to 25V
Operating junction temperature...........−40°C to 125°C
Electrical Characteristics
Symbol
Parameter
Power Supply (VCC Pin)
VCCON
UVLOON
VCCOFF
UVLOOFF
VCCHYS UVLO Hysteresis
VOVP
VCC OVP Trip Point
ISTART
Start-up Current
IQ Quiescent Current
ICC Operating Current
Error Amplifier
VFB Feedback Reference Voltage
Current Sense Comparator
tLEB Leading Edge Blanking Time
VCL Current Limit Threshold
VOCP
Over Current Trip Point
Over Current Release Point
Zero Current Detector
VZCDH
Upper Clamp Voltage
VZCDL
Lower Clamp Voltage
VZCDA
Positive-Going Edge
VZCDT
Negative-Going Edge
IOVP OVP Current on ZCD pin
tB_OVP
Blanking Time for OVP Detection
Starter
tSTART
Start Timer Period
tOFF Minimum Off Time
Over Temperature Protection
OTP
Over Temperature Trip Point
Test Condition
Before turn-on,
@ VCC = UVLOON - 1V
No switching
@ 70kHz, Co=1nF
Ta = 25°C
IZCD = 300μA
IZCD = -2.5mA
VCC=18V, Ta=25°C
Min Typ Max Unit
— 18
— 10
7—
26 29
—V
—V
—V
32 V
— 10 20 μA
— 0.6
1 mA
— 1.8 2.5 mA
194 200
206 mV
— 400
— 1.3
— 0.9
— 0.2
— ns
—V
—V
—V
—3
— -0.2
— 1.5
—1
270 300
—1
—V
—V
—V
—V
330 μA
μs
— 40
—4
μs
μs
— 150
— °C
Rev. 1.30
3 June 26, 2015







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