IC PWM CNTLLR 8DIP

UC3843AN

Manufacturer Part NumberUC3843AN
DescriptionIC PWM CNTLLR 8DIP
ManufacturerFairchild Semiconductor
UC3843AN datasheet
 

Specifications of UC3843AN

Pwm TypeControllerNumber Of Outputs1
Frequency - Max500kHzDuty Cycle100%
Voltage - Supply8.2 V ~ 30 VBuckNo
BoostNoFlybackNo
InvertingNoDoublerNo
DividerNoCukNo
IsolatedNoOperating Temperature0°C ~ 70°C
Package / Case8-DIP (0.300", 7.62mm)Frequency-max500kHz
Duty Cycle (max)100 %Output Current1000 mA
Mounting StyleThrough HoleSwitching Frequency500 KHz
Operating Supply Voltage30 VSupply Current17 mA
Maximum Operating Temperature+ 70 CFall Time40 ns
Minimum Operating Temperature0 CRise Time40 ns
Synchronous PinNoLead Free Status / RoHS StatusLead free / RoHS Compliant
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UC3842A/UC3843A
SMPS Controller
Features
• Low Start Current 0.2mA (typ)
• Operating Range Up To 500KHz
• Cycle by Cycle Current Limiting
• Under Voltage Lock Out With Hysteresis
• Short Shutdown Delay Time: typ.100ns
• High Current Totem-pole Output
• Output Swing Limiting: 22V
Internal Block Diagram
V
8
REF
Internal
Bias
1/2V
V
2
FB
COMP
1
C.S
3
R
/C
4
T
T
©2000 Fairchild Semiconductor International
Description
The UC3842A/UC3843A are fixed PWM controller for Off-
Line and DC to DC converter applications. The internal cir-
cuits include UVLO, low start up current circuit, tempera-
ture compensated reference, high gain error amplifier,
current sensing comparator, and high current totem-pole out-
put for driving a POWER MOSFET. Also UC3842A/
UC3843A provide low start up current below 0.3mA and
short shutdown delay time typ. 100ns. The UC3842A has
UVLO threshold of 16V(on) and 10V(off). The UC3843A is
8.4V(on) and 7.6V(off). The UC3842A and UC3843A can
operate within 100% duty cycle.
8-DIP
8-SOP
5V
SET/
V
RESET
REF
UVLO
Good LOGIC
REF
C.S
PWM
Error Amp
Comp.
LATCH
+
1/3
-
R
1V
S
OSCILLATOR
www.fairchildsemi.com
1
1
7
V
CC
29V
5
GND
PWR
7
V
C
22V
6
OUTPUT
PWR
5
GND
T
Rev. 5.0

UC3843AN Summary of contents

  • Page 1

    ... ©2000 Fairchild Semiconductor International Description The UC3842A/UC3843A are fixed PWM controller for Off- Line and converter applications. The internal cir- cuits include UVLO, low start up current circuit, tempera- ture compensated reference, high gain error amplifier, current sensing comparator, and high current totem-pole out- put for driving a POWER MOSFET ...

  • Page 2

    UC3842A/UC3843A Absolute Maximum Ratings Parameter Supply Voltage Output Current Analog Inputs (pin 2, 3) Error Amp. Output Sink Current Power Dissipation Electrical Characteristics (V = 15V 10K , C = 3.3nF Parameter REFERENCE SECTION ...

  • Page 3

    Electrical Characteristics (Continued 15V 10K , C = 3.3nF Parameter ERROR AMPLIFIER SECTION Input Voltage Input Bias Current Open Loop Gain Unity Gain Bandwidth PSRR Output Sink Current Output Source Current Output ...

  • Page 4

    UC3842A/UC3843A Mechanical Dimensions Package 6.40 0.20 0.252 0.008 #1 #4 7.62 0.300 4 8-DIP #8 #5 5.08 MAX 0.200 3.40 0.20 0.134 0.008 3.30 0.30 0.130 0.012 0.33 MIN 0.013 ...

  • Page 5

    Mechanical Dimensions Package #1 #4 0.156 0.50 0.20 0.020 0.008 (Continued) 8-SOP 1.55 0.20 0.061 0.008 #8 #5 6.00 0.30 1.80 MAX 0.236 0.012 0.071 3.95 0.20 0.008 5.72 0.225 UC3842A/UC3843A 0.1~0.25 MIN 0.004~0.001 5 ...

  • Page 6

    ... UC3842A/UC3843A Ordering Information Product Number UC3842AN UC3842AD UC3843AN UC3843AD 6 Package Operating Temperature 8 DIP 8 SOP DIP 8 SOP ...

  • Page 7

    UC3842A/UC3843A 7 ...

  • Page 8

    ... UC3842A/UC3843A LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR INTERNATIONAL. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, ...