Revised Date : 2007/11/20
Page No. : 1/14
˙Complete PWM Power Control Circuitry
˙Uncommitted Outputs for 200-mA Sink or
˙Output Control Selects Single-Ended or
˙Internal Circuitry Prohibits Double Pulse at
˙Variable Dead Time Provides Control Over
˙Internal Regulator Provides a Stable 5-V
Reference Supply With 5% Tolerance
˙Circuit Architecture Allows Easy Synchronization
PLASTIC PACKAGE DIP-16
PLASTIC PACKAGE SO-16
The PL494 incorporates on a single monolithic chip all the
functions required in the construction of a pulse-width-
modulation control circuit.
Designed primarily for power supply control, this device
offers the systems engineer the flexibility to tailor the power
supply control circuitry to a specific application.
The PL494 contains two error amplifiers, an on-chip
adjustable oscillator, a dead-time control (DTC)
comparator , a pulse-steering control flip-flop, a 5-V, 5%-
precision regulator, and output-control circuits.
The error amplifiers exhibit a common-mode voltage range
from –0.3V to Vcc –2V.
The dead-time control comparator has a fixed offset that
provides approximately 5% dead time. The on-chip
oscillator may be bypassed by terminating RT to the
reference output and providing a sawtooth input to CT, or it
may drive the common circuits in synchronous multiple-rail
INPUT TO OUTPUT CTRL
Single-ended or parallel output
Normal push-pull operation
PAIHAUNG Product Specification