Overview
The UC2879N, produced by Texas Instruments, is an enhanced bipolar phase-shifted full-bridge controller designed for high-efficiency power conversion applications. This controller is capable of operating in both voltage mode and current mode topologies, making it versatile for various power stage configurations. It features phase-shifting of one half-bridge with respect to the other, allowing for constant frequency pulse width modulation combined with resonant, zero-voltage switching. This design enhances efficiency and reduces switching losses. The UC2879N is available in a 20-pin PDIP (N) package and operates over a temperature range of -40°C to 85°C.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | 20-DIP (0.300", 7.62mm) | |
| Pins | 20 | |
| Operating Temperature Range | -40°C to 85°C | °C |
| Supply Voltage (Vcc/Vdd) | 9.25 V ~ 20 V | V |
| Switching Frequency | Up to 300 kHz | kHz |
| Duty Cycle | 50% | % |
| Startup Current | 150 µA | µA |
| Output Current (source or sink, dc) | 20 mA | mA |
| Fault Protection | Current Limiting, Overcurrent Protection | |
| Control Features | Frequency Control, Soft Start, Sync |
Key Features
- Programmable Output Turn On Delay; Zero Delay Available
- Compatible with Voltage Mode or Current Mode Topologies
- Practical Operation at Switching Frequencies to 300 kHz
- 10-MHz Error Amplifier
- Pin Programmable Undervoltage Lockout (UVLO)
- Low Startup Current of 150 µA
- Soft Start Control
- Outputs Active Low During UVLO
- External Clock Synchronization Capability
- Up to three units can be locked together for synchronized operation
Applications
The UC2879N is suitable for a variety of high-efficiency power conversion applications, including:
- Resonant and zero-voltage switching power supplies
- Full-bridge power stages in DC-DC converters
- High-frequency switching power supplies requiring low switching losses
- Applications needing precise control over switching frequencies and dead-time
Q & A
- What is the primary function of the UC2879N?
The UC2879N is a phase-shifted full-bridge controller designed to control a bridge power stage by phase-shifting the switching of one half-bridge with respect to the other.
- What are the operating temperature ranges for the UC2879N?
The UC2879N operates over a temperature range of -40°C to 85°C.
- What are the key features of the UC2879N?
The key features include programmable output turn-on delay, compatibility with voltage and current mode topologies, a 10-MHz error amplifier, pin-programmable UVLO, low startup current, and soft start control.
- What is the maximum switching frequency of the UC2879N?
The UC2879N can operate at switching frequencies up to 300 kHz.
- Can the UC2879N be synchronized with an external clock?
Yes, the UC2879N can be configured to accept an external clock synchronization signal via the CLKSYNC pin.
- What type of fault protection does the UC2879N offer?
The UC2879N offers overcurrent protection and undervoltage lockout (UVLO) for fault protection.
- What is the typical startup current of the UC2879N?
The typical startup current of the UC2879N is 150 µA.
- Can multiple UC2879N units be synchronized together?
Yes, up to three UC2879N units can be locked together for synchronized operation, with the operational frequency determined by the fastest device.
- What is the duty cycle of the UC2879N?
The duty cycle of the UC2879N is 50%.
- What package types are available for the UC2879N?
The UC2879N is available in 20-pin PDIP (N), J, DW, and Q packages, as well as a 28-pin L package.
