Overview
The UC3845AD8TR is a current-mode PWM controller from Texas Instruments, part of the UCx84xA family. This device is optimized for use in off-line and DC-DC converters, offering several improved features over its predecessors. It is characterized by a low start-up current of less than 0.5 mA, trimmed oscillator discharge current, and enhanced load response characteristics. The UC3845AD8TR is available in an 8-pin SOIC (D) package and operates over a temperature range of 0°C to 70°C.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Voltage Range | 3.5V to 40V | V |
| Start-Up Current | < 0.5 mA | mA |
| Oscillator Frequency | Up to 500 kHz | kHz |
| Maximum Duty Cycle | < 50% | % |
| Undervoltage Lockout (UVLO) | 8.4 V (on), 7.6 V (off) | V |
| Output Current Capability | Up to 1 A | A |
| Package Type | SOIC (D) 8-pin | - |
| Operating Temperature Range | 0°C to 70°C | °C |
Key Features
- 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
Applications
The UC3845AD8TR is suitable for a variety of power supply applications, including:
- Off-line power supplies
- DC-DC converters
- Switched-mode power supplies
- High-efficiency power conversion systems
Q & A
- What is the operating voltage range of the UC3845AD8TR?
The operating voltage range is from 3.5V to 40V.
- What is the start-up current of the UC3845AD8TR?
The start-up current is less than 0.5 mA.
- What is the maximum oscillator frequency of the UC3845AD8TR?
The maximum oscillator frequency is up to 500 kHz.
- What is the maximum duty cycle of the UC3845AD8TR?
The maximum duty cycle is less than 50%.
- What are the undervoltage lockout (UVLO) thresholds for the UC3845AD8TR?
The UVLO thresholds are 8.4 V (on) and 7.6 V (off).
- What is the output current capability of the UC3845AD8TR?
The output can source or sink up to 1 A of gate driver current.
- In what package is the UC3845AD8TR available?
The UC3845AD8TR is available in an 8-pin SOIC (D) package.
- What is the operating temperature range of the UC3845AD8TR?
The operating temperature range is from 0°C to 70°C.
- What are some key features of the UC3845AD8TR?
Key features include low start-up current, trimmed oscillator discharge current, automatic feedforward compensation, and pulse-by-pulse current limiting, among others.
- In which applications is the UC3845AD8TR commonly used?
The UC3845AD8TR is commonly used in off-line power supplies, DC-DC converters, and other switched-mode power supplies.
