UCC2808A-1Q1 Datasheet, PDF (1/11 Pages) Texas Instruments – LOW POWER CURRENT MODE PUSH-PULL PWM

UCC2808AĆ1Q1, UCC2808AĆ2Q1
LOW POWER CURRENT MODE PUSHĆPULL PWM
SGLS183 − AUGUST 2003
D Qualification in Accordance With
AEC-Q100^†
D Qualified for Automotive Applications
D Customer-Specific Configuration Control
Can Be Supported Along With
Major-Change Approval
D ESD Protection Exceeds 1500 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D Dual Output Drive Stages in Push-Pull
Configuration
D Current Sense Discharge Transistor to
Improve Dynamic Response
D 130-µA Typical Starting Current
D 1-mA Typical Run Current
D Operation to 1 MHz
D Internal Soft Start
† _{Contact factory for details. Q100 qualification data available on}
request.
D On-Chip Error Amplifier With 2-MHz Gain
Bandwidth Product
D On Chip VDD Clamping
D Output Drive Stages Capable of 500-mA
Peak-Source Current, 1-A Peak-Sink
Current
D PACKAGE
(TOP VIEW)
COMP ¹
FB 2
CS 3
RC ₄
8 VDD
7 OUTA
6 ^OUTB
5 ^GND
OUTA
VDD
COMP
FB
PW PACKAGE
(TOP VIEW)
1
8
2
7
3
6
4
5
OUTB
GND
RC
CS
description
The UCC2808A is a family of BiCMOS push-pull, high-speed, low-power, pulse-width modulators. The
UCC2808A contains all of the control and drive circuitry required for off-line or dc-to-dc fixed frequency
current-mode switching power supplies with minimal external parts count.
The UCC2808A dual output drive stages are arranged in a push-pull configuration. Both outputs switch at half
the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60 ns to
200 ns depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle
to less than 50%.
The UCC2808A family offers a variety of package options and choice of undervoltage lockout levels. The family
has UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown
in the ordering information table.
The UCC2808A is an enhanced version of the UCC2808 family. The significant difference is that the A versions
feature an internal discharge transistor from the CS pin to ground, which is activated each clock cycle during
the oscillator dead time. The feature discharges any filter capacitance on the CS pin during each cycle and helps
minimize filter capacitor values and current sense delay.
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  2003 Texas Instruments Incorporated
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