Overview
The UC2875N/81234, produced by Unitrode (now part of Texas Instruments), is a bipolar phase-shifted full-bridge controller integrated circuit. This component is designed to control a bridge power stage by phase-shifting the switching of one half-bridge with respect to the other, enabling constant frequency pulse-width modulation combined with resonant, zero-voltage switching for high efficiency performance at high frequencies.
The UC2875 family can be configured for either voltage or current mode operation and includes features such as separate over-current shutdown for fast fault protection and a programmable time delay for each output stage.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Temperature Range | -25°C to 85°C | °C |
| Supply Voltage Range | 9.5V to 20V | V |
| Startup Voltage | 10.75V | V |
| Package Type | 20-pin DIP (PDIP) | |
| Switching Frequency | Up to 1MHz | Hz |
| Output Type | Four 2A Totem Pole Outputs | |
| Undervoltage Lockout (UVLO) | 10.75V/9.25V with 1.5V hysteresis | V |
| Startup Current | 150µA | A |
| Supply Current (IIN) | 30 to 44mA | A |
| Voltage Reference Output | 4.92 to 5.08V | V |
| Error Amplifier Bandwidth | 7 to 11MHz | Hz |
Key Features
- Zero to 100% Duty Cycle Control
- Programmable Output Turn-On Delay
- Compatible with Voltage or Current Mode Topologies
- Practical Operation at Switching Frequencies up to 1MHz
- Four 2A Totem Pole Outputs
- 10MHz Error Amplifier
- Undervoltage Lockout (UVLO) with 1.5V hysteresis
- Low Startup Current of 150µA
- Outputs Active Low During UVLO
- Soft-Start Control
- Latched Over-Current Comparator With Full Cycle Restart
- Trimmed 5V Reference Output
Applications
The UC2875N/81234 is suitable for a variety of high-efficiency power conversion applications, including:
- Resonant and quasi-resonant converters
- High-frequency DC-DC converters
- Power supplies requiring high efficiency and reliability
- Industrial power systems
- Telecommunication power supplies
Q & A
- What is the primary function of the UC2875N/81234?
The UC2875N/81234 is a bipolar phase-shifted full-bridge controller integrated circuit 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 UC2875N/81234?
The operating temperature range is -25°C to 85°C.
- What is the supply voltage range for the UC2875N/81234?
The supply voltage range is 9.5V to 20V.
- What is the startup voltage for the UC2875N/81234?
The startup voltage is 10.75V.
- What type of package is the UC2875N/81234 available in?
The UC2875N/81234 is available in a 20-pin DIP (PDIP) package.
- What is the maximum switching frequency of the UC2875N/81234?
The maximum switching frequency is up to 1MHz.
- What protective features does the UC2875N/81234 have?
The UC2875N/81234 includes undervoltage lockout (UVLO), over-current protection with full-cycle restart, and soft-start control.
- How many output stages does the UC2875N/81234 have?
The UC2875N/81234 has four 2A totem pole outputs.
- What is the bandwidth of the error amplifier in the UC2875N/81234?
The error amplifier bandwidth is 7 to 11MHz.
- Can the UC2875N/81234 be synchronized with an external clock?
