Overview
The Texas Instruments UC3845N is a high-performance, single-ended current mode PWM (Pulse Width Modulation) controller. This component is specifically designed for off-line and DC-to-DC converter applications, offering a range of features that enhance the performance and reliability of power supply systems. The UC3845N is part of the UCx84x series, known for its robust and versatile design, making it suitable for various power management needs.
Key Specifications
| Specification | Value |
|---|---|
| Brand | Texas Instruments |
| Maximum Switching Frequency | 500 kHz |
| Output Current | 1 A |
| Number of Outputs | 1 |
| Control Method | Current Mode |
| Fall Time | 50 ns |
| Rise Time | 50 ns |
| Mounting Type | Through Hole |
| Package Type | PDIP |
| Pin Count | 8 |
| Topology | Boost, Buck, Flyback, Forward |
| Dimensions | 9.81 x 6.35 x 4.57 mm |
| Maximum Duty Cycle | 50% |
| Maximum Operating Temperature | +70 °C |
| Minimum Operating Temperature | 0 °C |
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
The UC3845N is widely used in various power supply applications, including:
- Off-line power supplies
- DC-to-DC converters
- Switch-mode power supplies
- Flyback, buck, boost, and forward converters
- High-performance power management systems requiring precise current mode control
Q & A
- What is the maximum switching frequency of the UC3845N?
The maximum switching frequency of the UC3845N is 500 kHz.
- What is the output current capability of the UC3845N?
The UC3845N can drive up to 1 A of output current.
- What is the control method used by the UC3845N?
The UC3845N uses current mode control.
- What are the typical rise and fall times of the UC3845N?
The typical rise and fall times are both 50 ns.
- What is the package type and pin count of the UC3845N?
The UC3845N comes in a PDIP package with 8 pins.
- What are the supported topologies for the UC3845N?
The UC3845N supports boost, buck, flyback, and forward topologies.
- What is the maximum duty cycle of the UC3845N?
The maximum duty cycle is 50%.
- What are the operating temperature ranges for the UC3845N?
The operating temperature range is from 0 °C to +70 °C.
- Does the UC3845N have undervoltage lockout (UVLO) protection?
- What is the purpose of the internally trimmed bandgap reference in the UC3845N?
The internally trimmed bandgap reference provides a stable voltage reference for the controller.
