Ⅰ. UC3842AN Description
Ⅱ. UC3842AN Pinout
Ⅲ. UC3842AN 3D Model
Ⅳ. UC3842AN Specifications
Ⅴ. UC3842AN Feature
Ⅵ. UC3842AN Applications
Ⅶ. UC3842AN VS UC3842N VS UC3842BN
Ⅷ. UC3842AN Packaging Information
Ⅸ. UC3842AN Datasheet
UC3842AN is a switching power supply IC chip. UC3842AN has functions such as PWM latch protection, push-pull amplification, power undervoltage protection, reference voltage generator, oscillator, error amplifier, and current comparator.
UC3842AN Current mode controller, PWM, 25V-12V power supply, 500 kHz, 5V/1A output, DIP-8.
1. UC3842AN Pinout
2. UC3842AN Pin Functions
Outputs the low impedance 1-MHz internal error amplifier that is also the input to the peak current limit or PWM comparator, with an open-loop gain (AVOL) of 80 dB. This pin is capable of sinking a maximum of 6 mA and is not internally current limited.
Input to the error amplifier that can be used to control the power converter voltage-feedback loop for stability.
This is the controller signal ground.
Input to the peak current limit, PWM comparator of the UCx84xA controllers. When used in conjunction with a current sense resistor, the error amplifier output voltage controls the power systems cycleby-cycle peak current limit. The maximum peak current sense signal is internally clamped to 1 V.
Output of 1-A totem pole gate driver. This pin can sink and source up to 1 A of gate driver current. A gate driver resistor must be used to limit the gate driver current.
Input to the internal oscillator that is programmed with an external timing resistor (RT) and timing capacitor (CT). TI recommends using capacitance values from 470 pF to 4.7 nF. TI also recommends that the timing resistor values chosen be from 5 kΩ to 100 kΩ.
Bias input to the gate driver. This pin must have a biasing capacitor that is at least 10 times greater than the gate capacitance of the main switching FET used in the design.
Reference voltage output of the PWM controller. This pin must supply no more than 10 mA under normal operation. This output is short-circuit protected at roughly 100 mA. This reference is also used for internal comparators and needs a high frequency bypass capacitor of 1 µF. The VCC capacitor also must be at least 10 times greater than the capacitor on the VREF pin.
2. UC3842AN Footprint
3. UC3842AN 3D Model
Current Mode PWM Controller
Number of PWM Outputs
Oscillator Accuracy (kHz)
Switching Frequency (kHz)
Maximum Duty Cycle (%)
Output Current (mA)
Rise Time (ns)
Fall Time (ns)
Output Voltage (V)
-0.1 to 11
Operating Supply Voltage (V)
Typical Operating Supply Voltage (V)
Maximum Operating Supply Voltage (V)
Maximum Supply Current (mA)
Maximum Power Dissipation (mW)
UVLO Turn-Off Threshold (V)
UVLO Turn-On Threshold (V)
Minimum Operating Temperature (°C)
Maximum Operating Temperature (°C)
5.08(Max) - 0.51(Min)
Standard Package Name
• Optimized for Off-Line and DC-DC Converters
• Low Start-Up Current (< 0.5 mA)
• Trimmed Oscillator Discharge Current
• Automatic Feedforward Compensation
• Pulse-by-Pulse Current Limiting
• Enhanced Load Response Characteristics
• Undervoltage Lockout With Hysteresis
• Double Pulse Suppression
• High-Current Totem Pole Output
• Internally-Trimmed Bandgap Reference
• Up to 500-kHz Operation
• Create a Custom Design Using the UCx84xA With the WEBENCH® Power Designer
• Switch Mode Power Supplies (SMPS)
• DC-DC Converters
• Power Modules
• Industrial PSU
• Battery Operated PSU
Switching Frequency (kHz)
Supply Voltage (DC)
Input voltage (DC)
Operating temperature (Max)
Operating temperature (Min)
10V ~ 30V
10V ~ 30V