TL594
PULSE WIDTH MODULATION CONTROL CIRCUIT
SLVS052F − APRIL 1988 − REVISED NOVEMBER 2003
D
Complete PWM Power-Control Circuitry
D
Uncommitted Outputs for 200-mA Sink or
D
D
D
D
D
D
Source Current
Output Control Selects Single-Ended 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%
Circuit Architecture Allows Easy
Synchronization
Undervoltage Lockout for Low-V
CC
Conditions
D, N, NS, OR PW PACKAGE
(TOP VIEW)
1IN+
1IN−
FEEDBACK
DTC
CT
RT
GND
C1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
2IN+
2IN−
REF
OUTPUT CTRL
VCC
C2
E2
E1
description/ordering information
The TL594 incorporates all the functions required in the construction of a pulse-width-modulation (PWM) control
circuit on a single chip. 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 TL594 contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC)
comparator, a pulse-steering control flip-flop, a 5-V regulator with a precision of 1%, an undervoltage lockout
control circuit, and output control circuitry.
The error amplifiers have a common-mode voltage range of −0.3 V to V
CC
− 2 V. The DTC comparator has a
fixed offset that provides approximately 5% dead time. The on-chip oscillator can be bypassed by terminating
RT to the reference output and providing a sawtooth input to CT, or it can be used to drive the common circuitry
in synchronous multiple-rail power supplies.
The uncommitted output transistors provide either common-emitter or emitter-follower output capability. Each
device provides for push-pull or single-ended output operation, with selection by means of the output-control
function. The architecture of these devices prohibits the possibility of either output being pulsed twice during
push-pull operation. The undervoltage lockout control circuit locks the outputs off until the internal circuitry is
operational.
The TL594C is characterized for operation from 0°C to 70°C. The TL594I is characterized for operation from
−40°C to 85°C.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright
2003, Texas Instruments Incorporated
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