Overview
The UC1843J/883B is a Current Mode PWM Controller from Texas Instruments, part of the UCx84x family of control integrated circuits. This device is optimized for off-line and DC-to-DC converters, offering a range of features that simplify the implementation of fixed-frequency current-mode control schemes with a minimum number of external components.
Designed for high-performance applications, the UC1843J/883B is specified for operation over a wide temperature range of –55°C to 125°C, making it suitable for various industrial and military environments.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| VCC (Low impedance source) | - | - | 30 | V |
| VFB and VISENSE (Analog input voltage) | -0.3 | - | 6.3 | V |
| OUTPUT drive current | - | - | ±1 A | A |
| COMP Error amplifier output sink current | - | - | 10 mA | mA |
| TJ Junction temperature | - | - | 150 °C | °C |
| Tstg Storage temperature | -65 °C | - | 150 °C | °C |
| fOSC Oscillator frequency | 100 kHz | - | 500 kHz | kHz |
| TA Operating free-air temperature | -55 °C | - | 125 °C | °C |
| VREF Reference voltage | 4.95 V | 5 V | 5.05 V | V |
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 converters
Q & A
- What is the operating temperature range of the UC1843J/883B?
The UC1843J/883B operates over a temperature range of –55°C to 125°C.
- What is the maximum output drive current of the UC1843J/883B?
The maximum output drive current is ±1 A.
- What is the oscillator frequency range of the UC1843J/883B?
The oscillator frequency range is from 100 kHz to 500 kHz.
- What type of output stage does the UC1843J/883B have?
The UC1843J/883B has a high-current totem-pole output stage.
- Does the UC1843J/883B have undervoltage lockout (UVLO) with hysteresis?
Yes, it includes undervoltage lockout with hysteresis.
- What is the reference voltage of the UC1843J/883B?
The reference voltage is 5 V with a tolerance of 4.95 V to 5.05 V.
- What are the typical applications of the UC1843J/883B?
Typical applications include switching regulators, transformer-coupled DC-DC converters, off-line power supplies, and DC-DC converters.
- What is the start-up current of the UC1843J/883B?
The start-up current is less than 1 mA.
- Does the UC1843J/883B support pulse-by-pulse current limiting?
Yes, it supports pulse-by-pulse current limiting.
- What is the error amplifier output sink current of the UC1843J/883B?
The error amplifier output sink current is up to 10 mA.
