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Current Mode PWM Controller

398

ic

The UC3844/UC3845 series are high-performance current mode controllers designed for off-line and DC-to-DC converters, featuring fixed frequency operation, current sensing, and adjustable output deadtime.

In stock

Specifications

8
Operating Voltage
15 V (typical) @ VCC = 12 V to 25 V, RT = 10 kΩ, CT = 3.3 nF, TA = Tlow to Thigh, unless otherwise noted.
Supply Current
ICC (Startup: -) @ VCC = 6.5 V for UCX845A, VCC 14 V for UCX844 mA
Interface
GPIO, PWM, ADC
Resolution
Not applicable
Range
Output voltage: -12 V to 13.5 V (with UVLO activated: -0.1 V to 1.1 V) V
Accuracy
Line regulation: -2 mV to +20 mV, Load regulation: -3 mV to +25 mV mV
Temperature Range
-25°C to 150°C (storage: -65°C to 150°C)
Package
8-pin dual-in-line plastic package, 14-pin plastic surface mount (SOIC-14)

Pinout

11
PinNameFunctionsNotes
1Compensation
GPIO
Error Amplifier output
2Voltage Feedback
GPIO
Inverting input of the Error Amplifier
3Current Sense
PWM
Input for current sensing and PWM termination
4RT/CT
GPIO
Programs oscillator frequency and maximum output duty cycle
5GND (8-pin package only)
GND
Control circuitry and power ground
6Output
PWM
Drives the gate of a power MOSFET, up to 1.0 A sourced/sunk
7VCC
POWER
Positive supply for the control IC
8Vref (8-pin package only)
ADC
Reference output, charges CT through RT
5 (14-pin package only)Power Ground
GND
Separate power ground return for the totem pole output stage
9GND (14-pin package only)
GND
Control circuitry ground return, connected back to power source ground
2, 4, 6, 13NC
No connection for the 14-pin package

Interactive pinout

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