Overview
The UC3875NG4, produced by Texas Instruments, is a bipolar phase-shifted full-bridge controller designed for high-efficiency power stage control. This integrated circuit is part of the UC3875 family, which implements phase-shifting of the switching of one half-bridge with respect to the other, enabling constant frequency pulse-width modulation and resonant, zero-voltage switching. This configuration allows for high efficiency performance at high frequencies.
Key Specifications
| Parameter | Value |
|---|---|
| Package Type | PDIP (N) |
| Pins | 20 |
| Operating Temperature Range (°C) | 0 to 70 |
| Undervoltage Lockout (UVLO) | 10.75V/9.25V |
| Startup Current | 150µA |
| Output Type | Four 2A Totem Pole Outputs |
| Error Amplifier Bandwidth | Exceeds 7MHz |
| Reference Voltage | 5V |
| Switching Frequency | Up to 1MHz |
| Over-Current Protection | Latched Over-Current Comparator With Full Cycle Restart |
| Soft-Start Control | Available |
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 to 1MHz
- Four 2A Totem Pole Outputs
- 10MHz Error Amplifier
- Undervoltage Lockout (UVLO)
- Low Startup Current of 150µA
- Outputs Active Low During UVLO
- Soft-Start Control
- Latched Over-Current Comparator With Full Cycle Restart
- Trimmed Reference
Applications
The UC3875NG4 is suitable for various high-efficiency power conversion applications, including but not limited to:
- Resonant and zero-voltage switching power supplies
- High-frequency DC-DC converters
- Bridge power stages in voltage or current mode operation
- Applications requiring fast fault protection and over-current shutdown
Q & A
- What is the primary function of the UC3875NG4?
The UC3875NG4 is a bipolar phase-shifted full-bridge controller designed for controlling bridge power stages with high efficiency at high frequencies. - What is the operating temperature range of the UC3875NG4?
The operating temperature range is 0°C to 70°C. - What is the undervoltage lockout (UVLO) threshold for the UC3875NG4?
The UVLO threshold is 10.75V with a 1.5V hysteresis. - How many output stages does the UC3875NG4 have?
The device has four 2A totem pole outputs. - What is the maximum switching frequency supported by the UC3875NG4?
The device can operate at switching frequencies up to 1MHz. - Does the UC3875NG4 have over-current protection?
Yes, it has a latched over-current comparator with full cycle restart. - What is the startup current of the UC3875NG4?
The startup current is 150µA. - Is the UC3875NG4 compatible with both voltage and current mode topologies?
Yes, it is compatible with both voltage and current mode topologies. - Can the UC3875NG4 be synchronized with an external clock signal?
Yes, it can be configured to accept an external clock synchronization signal. - What is the bandwidth of the error amplifier in the UC3875NG4?
The error amplifier bandwidth exceeds 7MHz.
