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UC2856Q
SGLS265 – NOVEMBER 2004
IMPROVED CURRENT MODE PWM CONTROLLER
FEATURES
•
•
Pin-for-Pin Compatible With the UC2846
65-ns Typical Delay From Shutdown to
Outputs and 50-ns Typical Delay From
Sync to Outputs
Improved Current Sense Amplifier With
Reduced Noise Sensitivity
Differential Current Sense With 3-V
Common Mode Range
Trimmed Oscillator Discharge Current for
Accurate Deadband Control
Accurate 1-V Shutdown Threshold
High Current Dual Totem Pole
Outputs (1.5-A peak)
TTL Compatible Oscillator SYNC Pin
Thresholds
4-kV ESD Protection
CL SS
VREF
CS−
CS+
EA+
EA−
COMP
CT
1
2
3
4
5
6
7
8
DW PACKAGE
(TOP VIEW)
16
15
14
13
12
11
10
9
•
•
•
•
•
•
•
SHUTDOWN
VIN
BOUT
VC
GND
AOUT
SYNC
RT
P0008-01
DESCRIPTION
The UC2856 is a high performance version of the popular UC2846 series of current mode controllers, and is
intended for both design upgrades and new applications where speed and accuracy are important. All input to
output delays have been minimized, and the current sense output is slew rate limited to reduce noise sensitivity.
Fast 1.5-A peak output stages have been added to allow rapid switching of power FETs.
A low impedance TTL compatible sync output has been implemented with a 3-state function when used as a
sync input.
Internal chip grounding has been improved to minimize internal
noise
caused when driving large capacitive
loads. This, in conjunction with the improved differential current sense amplifier, results in enhanced noise
immunity.
Other features include a trimmed oscillator current (8%) for accurate frequency and dead time control; a 1 V, 5%
shutdown threshold; and 4 kV minimum ESD protection on all pins.
ORDERING INFORMATION
(1)
T
A
–40°C to 125°C
(1)
PACKAGE
SOP–DW
Tape and reel
ORDERABLE
PART NUMBER
UC2856QDWR
TOP-SIDE
MARKING
UC2856Q
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design
guidelines are available at www.ti.com/sc/package.
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 © 2004, Texas Instruments Incorporated
TI [ TEXAS INSTRUMENTS ]
