UCC3882 Datasheet, PDF (1/16 Pages) Texas Instruments – AVERAGE CURRENT MODE SYNCHRONOUS CONTROLLER WITH 5-BIT DAC

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UCC3882/-1
SLUS294A – MARCH 1999 – REVISED OCTOBER 2005
AVERAGE CURRENT MODE SYNCHRONOUS
CONTROLLER WITH 5-BIT DAC
FEATURES
• Combined DAC/Voltage Monitor and PWM
With Synchronous Rectification Functions
• 5-Bit Digital-to-Analog (DAC) Converter
• 1% DAC/Reference Combined Accuracy
• Compatible with 5 V and 12 V Systems and 12
V-Only Systems
• Low Offset Current Sense Amplifier
• Programmable Oscillator Frequency Practical
to 700 kHz
• Foldback Current Limiting
• Overvoltage and Undervoltage Fault Windows
• 2-Ω Totem Pole Outputs with Programmable
Dead Times to Eliminate Cross-Conduction
• Chip Disable Function
DESCRIPTION
The UCC3882 combines high precision reference and
voltage monitoring circuitry with average current
mode PWM synchronous rectification controller
circuitry to power high-end microprocessors with a
minimum of external components. The UCC3882
converts 5 V or 12 V to an adjustable output ranging
from 1.8VDC to 2.05VDC in 50 mV steps and
2.1VDC to 3.5VDC in 100 mV steps with 1% DC
system accuracy.
BLOCK DIAGRAM
CAM
4
CAO
6
OVP
OVP (+ 17.5%)
VSNS 1
VFB 15
COMP 16
ISOUT 6
IS− ⁸
IS+ ₇
D0 27
D1 26
D2 24
D3 23
D4 22
Current Sense
Amplifier
X16
Output Offset
5 V REF
D/C Converter
2 V − 3.5 V, 100 mV
or
1.3 V − 2.05 V, 50 mV
Voltage
Amplifier
Current
Amplifier
OV
UV
3V
OV (+ 9%)
UV (−9%)
SQ
R
1.37 V
Foldback
Current
Limit
VSNS
Turn
On
Delay
RT
Anti Cross
Condition
Turn
On
Delay
RT
OSC
4.3 V/4.2 V
VIN
UVLO
10.5 V/10 V
5V
REF
2 PWRGD
19 ^VDRVHI
18 GATEHI
12 PGND
10 VDRVLO
11 GATELO
17 EN
9 VIN
21 VREF
28 ^GND
20
COMMAND
14 13
CT RT
UDG−97047−1
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 the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1999–2005, Texas Instruments Incorporated