AZ494B_05 Datasheet, PDF (1/12 Pages) BCD Semiconductor Manufacturing Limited – PULSE-WIDTH-MODULATION CONTROL CIRCUITS

Data Sheet
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
General Description
Features
AZ494B/D
The AZ494B/D is a voltage mode pulse width modula-
tion switching regulator control circuit designed prima-
rily for power supply control.
The AZ494B/D consists of a reference voltage circuit,
two error amplifiers, an on-chip adjustable oscillator, a
dead-time control (DTC) comparator, a pulse-steering
control flip-flop, and an output control circuit. The
AZ494B/D is capable for push-pull or single-ended
output operation, which can be selected through the
output control.
AZ494B has 4.95V and AZ494D has 5V reference
voltage respectively. The precision of voltage reference
(V_REF) is improved up to ± 1.5% through trimming
and this provides a better output voltage regulation.
The AZ494B/D is available in standard packages of
DIP-16 and SOIC-16.
· Stable 4.95V for AZ494B or 5V for AZ494D Ref-
erence Voltage Trimmed to ±1.5% Accuracy
· Uncommitted Output TR for 200mA Sink or
Source Current
· Single-End or Push-Pull Operation Selected by
Output Control
· Internal Circuitry Prohibits Double Pulse at Either
Output
· Complete PWM Control Circuit with Variable
Duty Cycle
· On-Chip Oscillator with Master or Slave Opera-
tion
Applications
· SMPS
· Back Light Inverter
· Charger
SOIC-16
DIP-16
Jun. 2005 Rev. 1. 1
Figure 1. Package Types of AZ494B/D
BCD Semiconductor Manufacturing Limited
1