Product Summary

The UC2844B is a high performance fixed frequency current mode controller. The device is specifically designed for Off-Line and dc-dc converter applications offering the designer a cost-effective solution with minimal external components. The UC2844B features an oscillator, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. The UC2844B also included are protective features consisting of input and reference under voltage lockouts each with hysteresis, cycle-by-cycle current limiting, a latch for single pulse metering, and a flip-flop which blanks the output off every other oscillator cycle, allowing output deadtimes to be programmed from 50% to 70%.

Parametrics

UC2844B absolute maximum ratings: (1)Total Power Supply and Zener Current, (ICC + IZ): 30 mA; (2)Output Current, Source or Sink, IO: 1.0 A; (3)Output Energy (Capacitive Load per Cycle), W: 5.0 μJ; (4)Current Sense and Voltage Feedback Inputs, Vin: -0.3 to +5.5 V; (5)Error Amp Output Sink Current, IO: 10 mA; (6)Power Dissipation and Thermal Characteristics, D Suffix, Plastic Package, SOIC-14 Case 751A, Maximum Power Dissipation @ TA = 25℃, Thermal Resistance, Junction-to-Air, PD: 862mW, RθJA: 145℃/W; D1 Suffix, Plastic Package, SOIC-8 Case 751; (7)Maximum Power Dissipation @ TA = 25℃, Thermal Resistance, Junction-to-Air, PD: 702mW, RθJA: 178℃/W; N Suffix, Plastic Package, Case 626, Maximum Power Dissipation @ TA = 25℃, Thermal Resistance, Junction-to-Air, PD: 1.25W, RθJA: 100℃/W; (8)Operating Junction Temperature, TJ: +150℃; (9)Operating Ambient Temperature, TA: -25 to +85℃; (10)Storage Temperature Range, Tstg: -65 to +150℃.

Features

UC2844B features: (1)Pb-Free Packages are Available; (2)Trimmed Oscillator for Precise Frequency Control; (3)Oscillator Frequency Guaranteed at 250 kHz; (4)Current Mode Operation to 500 kHz Output Switching Frequency; (5)Output Deadtime Adjustable from 50% to 70%; (6)Automatic Feed Forward Compensation; (7)Latching PWM for Cycle-By-Cycle Current Limiting; (8)Internally Trimmed Reference with Undervoltage Lockout; (9)High Current Totem Pole Output; (10)Undervoltage Lockout with Hysteresis; (11)Low Startup and Operating Current.

Diagrams

UC2844B block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
UC2844BD1
UC2844BD1

STMicroelectronics

Current Mode PWM Controllers 0.5mA Current Mode

Data Sheet

0-1: $0.43
1-10: $0.39
10-100: $0.32
100-250: $0.30
UC2844BD1013TR
UC2844BD1013TR

STMicroelectronics

Current Mode PWM Controllers 0.5mA Current Mode

Data Sheet

0-1950: $0.24
1950-2500: $0.24
UC2844BN
UC2844BN

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

0-1450: $0.26
1450-2000: $0.24
2000-5000: $0.23
UC2844BNG
UC2844BNG

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/48% Duty Cycle Max

Data Sheet

0-1: $0.38
1-25: $0.34
25-100: $0.25
100-500: $0.22
UC2844BDR2G
UC2844BDR2G

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/48% Duty Cycle Max

Data Sheet

0-1: $0.36
1-25: $0.32
25-100: $0.24
100-500: $0.21
UC2844BDR2
UC2844BDR2

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC2844BD1R2G
UC2844BD1R2G

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/48% Duty Cycle Max

Data Sheet

0-1: $0.36
1-25: $0.32
25-100: $0.24
100-500: $0.21
UC2844BD1R2
UC2844BD1R2

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable