Product Summary

The UC3843 is a current mode pwm controller. It provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits of the UC3843 include under voltage lock out featuring start-up current less than 1mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, the UC3843 also provides current limit control, and a totem pole output stage designed to source or sink high peakcurrent.

Parametrics

UC3843 absolute maximum ratings: (1)Vi Supply Voltage (low impedance source): 30 V; (2)IO Output Current: ±1 A; (3)EO Output Energy (capacitive load): 5 mJ; (4)Analog Inputs (pins 2, 3): -0.3 to 6.3 V; (5)Error Amplifier Output Sink Current: 10 mA; (6)Ptot Power Dissipation at Tamb ≤ 50 ℃ (minidip, DIP-14): 1 W; (7)Ptot Power Dissipation at Tamb ≤ 25 ℃ (SO14): 725 mW; (8)Tstg Storage Temperature Range: -65 to 150 ℃; (9)TL Lead Temperature (soldering 10s): 300 ℃.

Features

UC3843 features: (1)optimized for off-line and dc to dc converters; (2)lowstart-up current (< 1 ma); (3)automatic feed forward compensation; (4)pulse-by-pulsecurrent limiting; (5)enhanced load response characteristics; (6)under-voltage lockout with hysteresis; (7)double pulse suppression; (8)high current totem pole output; (9)internally trimmed bandgap reference; (10)500 khz operation; (11)low Ro erroramp.

Diagrams

UC3843 block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
UC3843
UC3843
Other

Data Sheet
Negotiable 
UC3843A
UC3843A
Other

Data Sheet
Negotiable 
UC3843AD
UC3843AD
Texas Instruments
Current Mode PWM Controllers Current Mode
Data Sheet
0-1: $0.85
1-25: $0.76
25-100: $0.67
100-250: $0.59
UC3843AD1
UC3843AD1
ON Semiconductor
Other Power Management 52kHz 1A Current PWM
Data Sheet
Negotiable 
UC3843AD1013TR
UC3843AD1013TR

IC REG CTRLR BST FLYBK ISO 8SOIC
Data Sheet
Negotiable 
UC3843AD1G
UC3843AD1G
ON Semiconductor
Other Power Management 52kHz 1A Current PWM w/96% Duty Cycle Max
Data Sheet
Negotiable 
UC3843AD1R2
UC3843AD1R2
ON Semiconductor
Other Power Management 52kHz 1A Current PWM
Data Sheet
Negotiable 
UC3843AD1R2G
UC3843AD1R2G
ON Semiconductor
Other Power Management 52kHz 1A Current PWM w/96% Duty Cycle Max
Data Sheet
Negotiable