Product Summary

The UC3842 is a Current-mode PWM controller. The UC3842 is available in an 8-Pin mini-DIP the necessary features to implement off-line, fixed-frequency current-mode control schemes with a minimal external parts count. This technique results in improved line regulation, enhanced load response characteristics, and a simpler, easier to design control loop. Topological advantages include inherent pulse-by-pulse current limiting. Protection circuitry includes built-in undervoltage lock-out and current limiting. Other features of UC3842 include fully-latched operation, a 1% trimmed bandgap reference, and start-up current less than 1mA. The UC3842 features a totem-pole output designed to source and sink high peak current from a capacitive load, such as the gate of a power MOSFET. Consistent with N-channel power devices, the output is low in the OFF-state.

Parametrics

UC3842 absolute maximum ratings: (1)Supply voltage (ICC<30mA), VCC: Self-Limiting; (2)Supply voltage(low impedance source), VCC: 30V; (3)Output current 2, 3, IOUT: ±1A; (4)Output energy (capacitive load): 5mJ; (5)Analog inputs (Pin 2, Pin 3): -0.3 to 6.3V; (6)Error amp output sink current: 10mA; (7)Power dissipation at TA370℃, PD: 1W; (8)Storage temperature range, TSTG: -65 to +150℃; (9)Lead temperature(soldering, 10sec max), TSOLD: 300℃.

Features

UC3842 features: (1)Low start-up current (31mA); (2)Automatic feed-forward compensation; (3)Pulse-by-pulse current limiting; (4)Enhanced load response characteristics; (5)Undervoltage lock-out with hysteresis; (6)Double pulse suppression; (7)High current totem-pole output; (8)Internally-trimmed bandgap reference; (9)400kHz operation, guaranteed min.

Diagrams

UC3842 pin connection

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
UC3842AD
UC3842AD

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
UC3842AD1
UC3842AD1

STMicroelectronics

Switching Converters, Regulators & Controllers 0.5mA Current Mode

Data Sheet

Negotiable 
UC3842AD8G4
UC3842AD8G4

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1: $0.85
1-25: $0.76
25-100: $0.67
100-250: $0.59
UC3842AD8TR
UC3842AD8TR

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1730: $0.33
1730-2000: $0.31
2000-2500: $0.31
2500-5000: $0.30
UC3842AD8TRG4
UC3842AD8TRG4

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1730: $0.33
1730-2000: $0.31
2000-2500: $0.31
2500-5000: $0.30
UC3842ADG4
UC3842ADG4

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
UC3842ADM
UC3842ADM


IC REG CTRLR BST FLYBK ISO 8SOIC

Data Sheet

0-1: $1.40
1-10: $1.26
10-100: $1.01
100-250: $0.90
250-500: $0.79
500-1000: $0.65
1000-2500: $0.61
2500-5000: $0.59
5000-10000: $0.56
UC3842ADR2
UC3842ADR2

ON Semiconductor

Other Power Management 52kHz 1A Current PWM

Data Sheet

Negotiable