Data Sheet
CURRENT MODE PWM CONTROLLER
General Description
The AP3842C/3C/4C/5C are high performance fixed
frequency 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 with 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 AP3842C and AP3844C have UVLO thresholds
of 16V(on) and 10V(off); The corresponding thresh-
olds for AP3843C and AP3845C are 8.4 V(on) and
7.6V(off).
The AP3842C and AP3843C can operate approaching
100% duty cycle; AP3844C and AP3845C can operate
from zero to 50% duty cycle.
These ICs are available in SOIC-8 and DIP-8 pack-
ages.
AP384XC
Features
·
·
·
·
·
·
·
·
Low Start-up Current: 50
µ
A
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/
o
C
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
·
·
·
·
·
·
Off-line Converter
DC-DC Converter
Voltage Adapter
CRT Monitor Power Supply
Desktop Power Supply
DVD/STB Power Supply
SOIC-8
DIP-8
Figure 1. Package Types of AP3842C/3C/4C/5C
Sep. 2006 Rev. 1. 1
BCD Semiconductor Manufacturing Limited
1
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
