TK732xx
LOW DROPOUT REGULATOR
FEATURES
APPLICATIONS
■ Up to 5 A Output Current Capability With External
PNP Transistor
■ Battery Powered Systems
■ Cellular/Cordless Telephones
■ Radio Control Systems
■ Internal Short Circuit Protection
■ Excellent Load Regulation
■ Wireless Communications Systems
■ Portable Instrumentations
■ CMOS/TTL-Compatible On/Off Switch
■ Internal Reverse Bias Current Protection Switch
■ Internal Thermal Shutdown
■ Portable Computers
■ Personal Digital Assistants
■ Local Area Network (LAN) Receivers
■ Lithium Ion Battery Chargers
■ Power Recovery for Microprocessors
■ Broad Operating Voltage Range
■ High Impedance VSENSE Pin (Off Mode)
■ Continuous and Pulsed Current Modes
DESCRIPTION
The TK732xx is a controller IC for a low dropout voltage
regulator. The TK732xx and the external PNP power
transistor provide standard output voltages from 2 to 11 V
and output current from 100 mA to 5 A. By utilizing an
external PNP power transistor, low dropout voltage at high
current can be readily achieved. The internal electronic
switch can be controlled by TTL or CMOS logic levels. The
device is in the “on” state when the control pin is pulled to
a high logic level. A pin for a bypass capacitor, which
connects to the internal circuitry, is provided to lower the
overall output noise level.
TK732xx
CONTROL
NOISE
BASE
V
SENSE
BYPASS
01S
C
GND
PULSE
V
I
PK
IN
The current limit characteristics can be configured as
continuous(constantcurrent)orpulsed(cycling).Aninternal
thermal shutdown circuit limits the junction temperatures
to below 150 °C. In the “off” mode, the output of the
regulator becomes a high impedance. This prevents the
output capacitor from being rapidly discharged for backup
to the load.
BLOCK DIAGRAM
I
V
SENSE
V
PK
C
BASE
IN
PULSE
ORDERING INFORMATION
TK732
M L
ON/OFF
CIRCUIT
THERMAL
SENSOR
Grade
Voltage Code
Package Code
Tape/Reel Code
Temp. Code
CONTROL
PACKAGE CODE
M: SOT-23L-8
VOLTAGE CODE
TAPE/REEL CODE
L: Tape Left
20 = 2.0 V *
21 = 2.1 V *
22 = 2.2 V *
23 = 2.3 V *
24 = 2.4 V
25 = 2.5 V
26 = 2.6 V
27 = 2.7 V
28 = 2.8 V
29 = 2.9 V
30 = 3.0 V
31 = 3.1 V
32 = 3.2 V
44 = 4.4 V
BANDGAP
REFERENCE
33 = 3.3 V
34 = 3.4 V
35 = 3.5 V
36 = 3.6 V
37 = 3.7 V
38 = 3.8 V
39 = 3.9 V
40 = 4.0 V
41 = 4.1 V
42 = 4.2 V
43 = 4.3 V
45 = 4.5 V
46 = 4.6 V
47 = 4.7 V
48 = 4.8 V
49 = 4.9 V
50 = 5.0 V
55 = 5.5 V *
70 = 7.0 V *
80 = 8.0 V
11 = 11.0 V
GRADE
LEAKAGE
PROTECTION
TEMP. RANGE
C: -30 to 80 C **
None: Standard 2%
I : -40 to 85
C
H: High (Special) ***
* Unavailable with I Rank
** unless Otherwise Specified
*** TK73241MCLH, TK73242MCLH Available Only
GND
NOISE BYPASS
January 1999 TOKO, Inc.
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