集成运放TL494(图

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1IN
1IN−
FEEDBACK
DTC
*
RT
GND
C1
2IN
2IN−
REF
OUTPUT *RL
VCC
C2
E2
E1
D, DB, N, NS, OR PW PACKAGE
(TOP VIEW)
D*CRIPTION
TL494
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074E–JANUARY 1983–REVISED FEBRUARY 2005
· Complete PWM Power-Control Circuitry
· Uncommitted Outputs for 200-mA Sink or
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 With 5% Tolerance
· Circuit Architecture Allows Easy
Synchronization
The TL494 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 flexibility to tailor the
power-supply control circuitry to a specific application.
The TL494 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 –0.3 V to VCC – 2 V. The dead-time control
comparator has a fixed offset that provides approximay 5% dead time. The on-chip oscillator can be b**ed
by terminating RT to the reference output and providing a sawtooth input to *, or it can drive the common
circuits in synchronous multiple-rail power supplies.
The uncommitted output transistors provide either common-emitter or emitter-follower output capability. The
TL494 provides for push-pull or single-ended output operation, which can be selected through the output-control
function. The architecture of this device prohibits the possibility of either output being pulsed twice during
push-pull operation.
The TL494C is characterized for operation from 0°C to 70°C. The TL494I is characterized for operation from
–40°C to 85°C.
*AILABLE OPTIONS
PACKAGED DEVIC*(1)
T SHRINK SMALL THIN SHRINK A SMALL OUTLINE PLASTIC DIP SMALL OUTLINE OUTLINE SMALL OUTLINE (D) (N) (NS) (DB) (PW)
0°C to 70°C TL494CD TL494CN TL494CNS TL494CDB TL494CPW
–40°C to 85°C TL494ID TL494IN — — —
(1) The D, DB, NS, and PW packages are available taped and reeled. Add检修方法。