Product Summary

The UC1842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC3842/3/4/5 family. Providing the nec-essary features to control current mode switched mode powersupplies, this family has the following improved features. Start up cur-rent is guaranteed to be less than 0.5mA. Oscillator discharge istrimmed to 8.3mA. During under voltage lockout, the output stagecan sink at least 10mA at less than 1.2V for VCC over 5V

Parametrics

The absolute maximum ratings of UC3844A are
(1)Supply Voltage (Low Impedance Source): 30V;
(2)Supply Voltage (ICC mA): Self Limiting;
(3)Output Current: ±1A;
(4)Output Energy (Capacitive Load): 5μJ;
(5)Analog Inputs (Pins 2, 3): -03V to +63V;
(6)Error Amp Output Sink Current: 10mA;
(7)Power Dissipation at TA≤ 25°C (DIL-8): 1W;
(8)Storage Temperature Range: -65°C to +150°C;
(9)Lead Temperature (Soldering, 10 Seconds): 300°C

Features

The features of UC3844A can be summarized as
(1)Optimized for Off-line and DC to DC Converters;
(2)Low Start Up Current (<0.5mA);
(3)Trimmed Oscillator Discharge Current;
(4)Automatic Feed Forward Compensation;
(5)Pulse-by-Pulse Current Limiting;
(6)Enhanced Load Response Characteristics;
(7)Under-Voltage Lockout With Hysteresis;
(8)Double Pulse Suppression;
(9)High Current Totem Pole Output;
(10)Internally Trimmed Bandgap Reference;
(11)500kHz Operation; (12)Low RO Error Amp

Diagrams

<DIV><IMG alt="UC3844A Pin Configuration" src="http://www.seekic.com/uploadfile/ic-mfg/2012711202546644.jpg" border=0></DIV>

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
UC3844AD
UC3844AD
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
UC3844AD1
UC3844AD1
STMicroelectronics
Switching Converters, Regulators & Controllers RO 511-UC3844BD 9/04
Data Sheet
Negotiable 
UC3844AD8
UC3844AD8
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
UC3844AD8G4
UC3844AD8G4
Texas Instruments
Current Mode PWM Controllers Current-Mode PWM Controller
Data Sheet
0-1: $0.85
1-25: $0.68
25-100: $0.62
100-250: $0.55
UC3844AD8TR
UC3844AD8TR
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
UC3844AD8TRG4
UC3844AD8TRG4
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
UC3844ADG4
UC3844ADG4
Texas Instruments
Current Mode PWM Controllers Current Mode
Data Sheet
0-1: $0.85
1-25: $0.68
25-100: $0.62
100-250: $0.55
UC3844ADM
UC3844ADM

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