HT7L4811 Datasheet, PDF (1/12 Pages) Holtek Semiconductor Inc – Non-isolation Buck LED Lighting Driver with Active PFC

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 shortprotection
♦♦ 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