HT7A4016 Datasheet, PDF (1/12 Pages) Holtek Semiconductor Inc – Low Power, Wide Temperature Range General Purpose Current Mode PWM Controller

HT7A4016
Low Power, Wide Temperature Range General
Purpose Current Mode PWM Controller
Feature
• High Performance, Low Cost Current Mode PWM
Controller especially designed for Energy Star 2.0
• Very Low Startup Current (<20μA) and Operating
Current
• High-Voltage CMOS Process with Excellent ESD
protection (>3KV)
• ±5% Trimmed Oscillator for Precise Frequency
Control
• LEB (Leading-Edge Blanking) on CS Pin
• Internal Slope Compensation
• Programmable Switching Frequency
• Internally Trimmed Reference with UVLO (Under
Voltage Lockout)
• Cycle-by-Cycle Current Limiting
Applications
• Switching AC-DC Adaptors
• DC-DC Switching Buck/Boost Converters
• LED Backlights for LCD/LED TVs
General Description
The HT7A4016 is a controller IC that includes the
necessary features to implement off-line or DC-DC
current mode control schemes with a minimal external
parts count. Internal circuits include a specially
designed Mixed-Mode/Analog Interface for multi-
function and multi-topology control schemes (DC-DC
Buck/Boost, Off-line AC-DC), a trimmed oscillator
for precise duty-cycle control under voltage lockout
with a start-up current of less than 0.5mA, a wide
temperature range, precise voltage reference, internal
Slope Compensation and Leading-Edge Blanking.
The HT7A4016 features basic system protection
functions such as Cycle-by-Cycle Current Limiting
and Under Voltage Lock-Out (UVLO).
A Multi-Function Pin can be used as a dimming
function for LED driving, and as a primary feedback
control for Primary-Side Feedback AC-DC
applications.
Application Circuits
VIN=24V
0.1uF
VCC
2.2K
Vref
GD
RT
COMP/FB
GND
CS
MF
470uF/50V
10 1N4148
20
10K
33pF
470K
1nF
46uH
HFB20HJ20C
IRF540
0.22
820
0.22
220pF _40K
470uF
/63V
Vo=55V/75W
0.1uF/100V
2K
Rev. 1.00
1
November 07, 2011