UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
D Extended Temperature Performance of
–40°C to 125°C
D Optimized for Off-line and DC to DC
Converters
D Low Start Up Current (<0.5 mA)
D Trimmed Oscillator Discharge Current
D Automatic Feed Forward Compensation
D Pulse-by-Pulse Current Limiting
D Enhanced Load Response Characteristics
D Under-Voltage Lockout With Hysteresis
D Double Pulse Suppression
D High Current Totem Pole Output
D Internally Trimmed Bandgap Reference
D 500 kHz Operation
D Low RO Error Amp
description
SGLS164 – APRIL 2003
D 8-PIN PACKAGE
(TOP VIEW)
COMP
VFB
ISENSE
RT/CT
1
2
3
4
8 VREF
7 VCC
6 OUTPUT
5 GND
D 14-PIN PACKAGE
(TOP VIEW)
COMP
NC
VFB
NC
ISENSE
NC
RT/CT
1
2
3
4
5
6
7
14 VREF
13 NC
12 VCC
11 VC
10 OUTPUT
9 GND
8 PWR GND
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 VCC over
5 V.
The difference between members of this family are shown in the table below.
PART NUMBER
UC2842A
UC2843A
UC2844A
UC2845A
UVLO ON
16 V
8.5 V
16 V
8.5 V
UVLO OFF
10 V
7.9 V
10 V
7.9 V
MAXIMUM DUTY CYCLE
<100%
<100%
<50%
<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.
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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