ą TL497A 500ĆmA PEAK STEPĆUP, STEPĆDOWN, INVERTING SWITCHING VOLTAGE REGULATOR
SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005
D High Efficiency . . . 60% or Greater D Peak Switch Current . . . 500 mA D Input Current Limit Protection D TTL-Compatible Inhibit D Adjustable Output Voltage D Input Regulation . . . 0.2% Typ D Output Regulation . . . 0.4% Typ D Soft Start-Up Capability D Can be Used in Buck, Boost, and
Inverting Configurations
description/ordering information
D, N, OR PW PACKAGE (TOP .
SWITCHING VOLTAGE REGULATORS
ą TL497A 500ĆmA PEAK STEPĆUP, STEPĆDOWN, INVERTING SWITCHING VOLTAGE REGULATOR
SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005
D High Efficiency . . . 60% or Greater D Peak Switch Current . . . 500 mA D Input Current Limit Protection D TTL-Compatible Inhibit D Adjustable Output Voltage D Input Regulation . . . 0.2% Typ D Output Regulation . . . 0.4% Typ D Soft Start-Up Capability D Can be Used in Buck, Boost, and
Inverting Configurations
description/ordering information
D, N, OR PW PACKAGE (TOP VIEW)
COMP INPUT INHIBIT
FREQ CONTROL SUBSTRATE GND CATHODE ANODE
1 2 3 4 5 6 7
14 VCC 13 CUR LIM SENS 12 BASE DRIVE† 11 BASE†
10 COL OUT
9 NC
8 EMIT OUT
NC − No internal connection † BASE (11) and BASE DRIVE (12) are used for device testing
only. They normally are not used in circuit applications of the
device.
The TL497A incorporates all the active functions required in the construction of switching voltage regulators. It also can be used as the control element to drive external components for high-power-output applications. The TL497A was designed for ease of use in step-up, step-down, or voltage-inversion applications requiring high efficiency.
The TL497A is a fixed-on-time variable-frequency switching-voltage-regulator control circuit. The switch-on
time is programmed by a single external capacitor connected between FREQ CONTROL and GND. This
capacitor, CT, is charged by an internal constant-current generator to a predetermined threshold. The charging current and the thresho.