Complete PWM Power-Control Function

Totem-Pole Outputs for 200-mA Sink or

Source Current

Output Control Selects Parallel or

Push-Pull Operation

Internal Circuitry Prohibits Double Pulse at

Either Output

Variable Dead-Time Provides Control Over

Total Range

Internal Regulator Provides a Stable 5-V

Reference Supply, Trimmed to 1%

Tolerance

On-Board Output Current-Limiting

Protection

Undervoltage Lockout for Low-VCC

Conditions

Separate Power and Signal Grounds

description/ordering information

The TL598 incorporates all the functions required in the construction of pulse-width-modulated (PWM)

controlled systems on a single chip. Designed primarily for power-supply control, the TL598 provides the

systems engineer with the flexibility to tailor the power-supply control circuits to a specific application.

The TL598 contains two error amplifiers, an internal oscillator (externally adjustable), a dead-time control (DTC)

comparator, a pulse-steering flip-flop, a 5-V precision reference, undervoltage lockout control, and output

control circuits. Two totem-pole outputs provide exceptional rise- and fall-time performance for power FET

control. The outputs share a common source supply and common power ground terminals, which allow system

designers to eliminate errors caused by high current-induced voltage drops and common-mode noise.

The error amplifier has a common-mode voltage range of 0 V to VCC − 2 V. The DTC comparator has a fixed

offset that prevents overlap of the outputs during push-pull operation. A synchronous multiple supply operation

can be achieved by connecting RT to the reference output and providing a sawtooth input to CT.

The TL598 device provides an output control function to select either push-pull or parallel operation. Circuit

architecture prevents either output from being pulsed twice during push-pull operation. The output frequency

for push-pull applications is one-half the oscillator frequency
fO 

1

2 RT CT. For single-ended applications:

fO 

1

RT CT

.