AZ3842 Datasheet, PDF (1/13 Pages) Advanced Analog Technology, Inc. – CURRENT MODE PWM CONTROLLER

Advanced Analog Circuits
CURRENT MODE PWM CONTROLLER
General Description
Features
Data Sheet
AZ3842/3/4/5
The AZ3842/3/4/5 are high performance fixed fre-
quency current-mode PWM controller series.
These integrated circuits are optimized for off-line and
DC-DC converter applications with minimum external
components. They feature under-voltage lockout
(UVLO) circuit for low start-up current, trimmed
oscillator for precise duty cycle control, current sense
comparator providing maximum current limiting and a
totem pole output stage for increasing output current.
In addition, these ICs also feature accurate protection
against over-temperature, over-current and maximal
output power.
The AZ3842 and AZ3844 have UVLO thresholds of
15.5V(on) and 10V(off); The corresponding thresholds
for AZ3843 and AZ3845 are 8.4 V(on) and 7.8V(off).
· Robust V_REF Line/Load Regulation
Low Line Regulation : 4mV
Low Load Regulation : 4mV
· High Stability of Reference Voltage over a Full
Temperature Range: 0.2mV/ ^oC
· Operating Frequency up to 500KHz
· High PWM Frequency Stability over a Full Tem-
perature Range: 2.5%
· High PWM Frequency Stability under a Full Sup-
ply Voltage Range: 0.2%
· Accurate Over-temperature Protection with Hys-
teresis
· UVLO with Hysteresis
Applications
The AZ3842 and AZ3843 can operate approaching ^{· Off-line Converter}
100% duty cycle; AZ3844 and AZ3845 can operate ^{· DC-DC Converter}
from zero to 50% duty cycle.
· Voltage Adapter
· CRT Monitor Power Supply
These ICs are available in 3 packages: SOIC-8, DIP-8 _{· Desktop Power Supply}
and SOIC-14.
· DVD/STB Power Supply
March 2003
SOIC-8
DIP-8
SOIC-14
Figure 1. Package Types of AZ3842/3/4/5
1
Rev: 1.0