TPS6734I Datasheet, PDF (1/19 Pages) Texas Instruments – FIXED 12-V 120-mA BOOST-CONVERTER SUPPLY

TPS6734I
FIXED 12-V 120-mA BOOST-CONVERTER SUPPLY
D Pin-for-Pin Compatible With MAX734
D Programming Voltage for Flash Memory
D 2.7-V to 11-V Input Operating Range
D Output Current of 120 mA or Greater From
3.75-V or Higher Input
D 3-µA Maximum Supply Current in
Shutdown
D Only 5 External Components Required
D High Efficiency . . . 85% Typical (5-V Input,
120-mA Output)
D 8-Pin SOIC and DIP Packages
D – 40°C to 85°C Free-Air Operating
Temperature Range
SLVS127A – AUGUST 1995 – REVISED JANUARY 1999
D OR P PACKAGE
(TOP VIEW)
EN 1
REF 2
SS 3
COMP 4
8 V_CC
7 FB
6 OUT
5 GND
description
The TPS6734 is a fixed 12-V output boost converter capable of delivering 120 mA from inputs as low as
3.75 V. The device is pin-for-pin compatible with the MAX734 regulator and offers the following advantages:
lower supply current, wider operating input-voltage range, and higher output currents. As shown in Figure 1,
the only external components required are: an inductor, a Schottky rectifier, an output filter capacitor, an input
filter capacitor, and a small capacitor for loop compensation. The entire converter occupies less than 0.7 in² of
PCB space when implemented with surface-mount components. An enable input is provided to shut down the
converter and reduce the supply current to 3 µA when 12 V is not needed.
The TPS6734 is a 170-kHz current-mode PWM ( pulse-width modulation) controller with an n-channel MOSFET
power switch. Gate drive for the switch is derived from the 12-V output after start-up to minimize the die area
needed to realize the 0.7-Ω MOSFET and improve efficiency at input voltages below 5 V. Soft start is
accomplished with the addition of one small capacitor. A 1.22-V reference (pin 2) is brought out for external use.
High efficiency at low supply voltages and low supply current in shutdown make the TPS6734 particularly
attractive for flash memory programming supplies, PCMCIA cards, and operational amplifiers in
battery-powered equipment. The TPS6734 is available in 8-pin DIP and SOIC packages and operates over a
free-air temperature range of – 40°C to 85°C.
VI
3.75 V to 12 V
ENABLE
TPS6734
1 _EN
2 _REF
VCC ⁸
FB ⁷
3 _SS
OUT ⁶
4
5
COMP GND
0.001 µF
18 µH
1A, 20 V
+
33 µF
VO
12 V, 120 mA
Figure 1. Typical Operating Circuit
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.
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Copyright © 1999, Texas Instruments Incorporated
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