Overview
The UC3842ADG4 is a high-performance, fixed-frequency, current-mode PWM controller manufactured by Texas Instruments. This device is part of the UCx84x series, which is optimized for off-line and DC-to-DC converter applications. It offers a cost-effective solution with a minimal number of external components required. The UC3842ADG4 is designed to operate within a temperature range of 0°C to 70°C, making it suitable for a variety of power supply and converter designs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC (Low impedance source) | - | - | 30 | V |
| IVCC (Self Limiting) | - | - | 30 mA | mA |
| VVFB and VISENSE (Analog input voltage) | -0.3 | - | 6.3 | V |
| IOUTPUT (Output drive current) | - | - | ±1 A | A |
| ICOMP (Error amplifier output sink current) | - | - | 10 mA | mA |
| TJ (Junction temperature) | - | - | 150 °C | °C |
| Tstg (Storage temperature) | -65 | - | 150 °C | °C |
| fOSC (Oscillator frequency) | 47 | 50 | 52 kHz | kHz |
| VREF (Reference output voltage) | 4.9 | 5.0 | 5.1 V | V |
| UVLO Enable threshold | 14.5 | 16 | 17.5 V | V |
| UVLO Off threshold | 8.5 | 10 | 11.5 V | V |
| Maximum duty cycle | 95% | 97% | 100% | % |
Key Features
- Optimized for off-line and DC-to-DC converters
- Low start-up current (< 1 mA)
- 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
- Error amplifier with low output resistance
Applications
- Switching regulators of any polarity
- Transformer-coupled DC-DC converters
- Off-line power supplies
- DC-DC converter applications
Q & A
- What is the operating temperature range of the UC3842ADG4?
The UC3842ADG4 operates within a temperature range of 0°C to 70°C.
- What is the maximum output current of the UC3842ADG4?
The output drive current can be up to ±1 A.
- What is the oscillator frequency range of the UC3842ADG4?
The oscillator frequency can be programmed up to 500 kHz, with a typical range of 47 kHz to 52 kHz.
- What is the reference output voltage of the UC3842ADG4?
The reference output voltage is typically 5 V, with a range of 4.9 V to 5.1 V.
- Does the UC3842ADG4 have undervoltage lockout (UVLO) protection?
Yes, the UC3842ADG4 features undervoltage lockout with hysteresis.
- What are the typical applications of the UC3842ADG4?
The UC3842ADG4 is typically used in switching regulators, transformer-coupled DC-DC converters, off-line power supplies, and DC-DC converter applications.
- What is the maximum duty cycle of the UC3842ADG4?
The maximum duty cycle can be up to 100%.
- Does the UC3842ADG4 have pulse-by-pulse current limiting?
Yes, the UC3842ADG4 features pulse-by-pulse current limiting.
- What is the start-up current of the UC3842ADG4?
The start-up current is less than 1 mA.
- What package options are available for the UC3842ADG4?
The UC3842ADG4 is available in various package options including SOIC, PDIP, and CFP.
