UCC28C40_14 Datasheet, PDF (1/34 Pages) Texas Instruments – BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLER

UCC28C40, UCC28C41, UCC28C42, UCC28C43, UCC28C44, UCC28C45
UCC38C40, UCC38C41, UCC38C42, UCC38C43, UCC38C44, UCC38C45
SLUS458E -- AUGUST 2001 -- REVISED OCTOBER 2010
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLER
FEATURES
D Enhanced Replacement for UC3842A Family
With Pin-to-Pin Compatibility
D 1-MHz Operation
D 50-μA Standby Current, 100-μA Maximum
D Low Operating Current of 2.3 mA at 52 kHz
D Fast 35-ns Cycle-by-Cycle Overcurrent
Limiting
D ±1-A Peak Output Current
D Rail-to-Rail Output Swings with 25-ns Rise
and 20-ns Fall Times
D ±1% Initial Trimmed 2.5-V Error Amplifier
Reference
D Trimmed Oscillator Discharge Current
D New Under Voltage Lockout Versions
D MSOP-8 Package Minimizes Board Space
APPLICATIONS
D Switch-Mode Power Supplies
D dc-to-dc Converters
D Board Mount Power Modules
FUNCTIONAL BLOCK DIAGRAM
DESCRIPTION
UCC38C4x family is a high-performance current-
mode PWM controller. It is an enhanced BiCMOS
version with pin-for-pin compatibility to the
industry standard UC384xA family and UC384x
family of PWM controllers. In addition, lower
startup voltage versions of 7 V are offered as
UCC38C40 and UCC38C41.
Providing necessary features to control fixed
frequency, peak current-mode power supplies,
this family offers the following performance
advantages. The device offers high-frequency
operation up to 1 MHz with low start-up and
operating currents, thus minimizing start-up loss
and low operating power consumption for
improved efficiency. The device also features a
very fast current-sense-to-output delay time of
35 ns and a ±1 A peak output current capability
with improved rise and fall times for driving large
external MOSFETs directly.
The UCC38C4x family is offered in 8-pin
packages, MSOP (DGK), SOIC (D) and PDIP (P).
VREF 8
5.0 V
VREF
VREF
GOOD LOGIC
UVLO
+
7 VDD
5 GND
RT/CT 4
OSC
2.5 V
FB 2
ERROR AMP
+
COMP 1
2R
R
1V
(NOTE)
T
SQ
RQ
CS 3
Note: Toggle flip--flop used only in UCC38C41, UCC38C44, and UCC38C45.
6 OUT
UDG--99139
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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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