UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
SGLS164 – APRIL 2003
D 8-PIN PACKAGE
(TOP VIEW)
D
D
Extended Temperature Performance of
–40°C to 125°C
Optimized for Off-line and DC to DC
Converters
COMP
V
V
1
2
3
4
8
7
6
5
REF
CC
V
FB
D
D
D
D
D
D
D
D
D
D
D
Low Start Up Current (<0.5 mA)
Trimmed Oscillator Discharge Current
Automatic Feed Forward Compensation
Pulse-by-Pulse Current Limiting
Enhanced Load Response Characteristics
Under-Voltage Lockout With Hysteresis
Double Pulse Suppression
I
OUTPUT
GND
SENSE
R /C
T
T
D 14-PIN PACKAGE
(TOP VIEW)
COMP
NC
V
REF
1
2
3
4
5
6
7
14
13
12
11
10
9
NC
V
V
High Current Totem Pole Output
Internally Trimmed Bandgap Reference
500 kHz Operation
FB
NC
CC
V
C
I
OUTPUT
GND
SENSE
NC
Low R Error Amp
O
R /C
PWR GND
8
T
T
description
The UC2842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC2842/3/4/5
family. Providing the necessary features to control current mode switched mode power supplies, this family has the
following improved features. Start up current is guaranteed to be less than 0.5 mA. Oscillator discharge is trimmed
to 8.3 mA. During under voltage lockout, the output stage can sink at least 10 mA at less than 1.2 V for V
5 V.
over
CC
The difference between members of this family are shown in the table below.
PART NUMBER
UC2842A
UVLO ON
16 V
UVLO OFF
10 V
MAXIMUM DUTY CYCLE
<100%
<100%
<50%
UC2843A
8.5 V
7.9 V
UC2844A
16 V
10 V
UC2845A
8.5 V
7.9 V
<50%
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.
Copyright 2003, Texas Instruments Incorporated
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.
1
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