PULSE-WIDTH-MODULATION CONTROL CIRCUIT
DESCRIPTION
The UTC TL594 is a PWM (Pulse Width Modulation) control
circuit, incorporating two error amplifiers, an on-chip adjustable
oscillator, a DTC (Deadtime Control) comparator, a pulse-steering
control flip-flop, a regulator rated 5V with 1% accuracy, an UVLO
(Undervoltage Lockout) control circuit and an output control circuit.
The two error amplifiers have a common-mode voltage varies from
-0.3 V to VCC-2 V. The DTC comparator with a fixed-offset offers
dead time nearly 5%. The UVLO circuit forbids the output until the
internal circuitry is operational. The internal oscillator is used to drive
the common circuits in synchronous multiple-rail power supplies,
when be bypassed by terminating RT to the reference output and
providing an external input of sawtooth to CT.
The uncommitted output transistors have the capabilities of
either common-emitter or emitter-follower output. The output control
can select the push-pull or single-ended output operation for each
device. This chip is not allowed to appear the double pulse status for
either output during push-pull output operation due to its structure.
The UTC TL594 is generally used for the power supply control
circuits, which apply to a large area |
