Overview
The UC2846NG4 is a current-mode PWM (Pulse Width Modulation) controller produced by Texas Instruments. It is part of the UCx846/7 family of control devices, designed to implement fixed-frequency, current-mode control schemes in power conversion applications. This device is known for its minimal external parts count, making it a versatile and efficient solution for various power supply designs.
The UC2846NG4 features a range of internal circuits, including under-voltage lockout, a precision reference voltage, logic for latched operation, a PWM comparator with current limit control, and a totem pole output stage capable of sourcing or sinking high-peak currents. These features contribute to improved line regulation, enhanced load response characteristics, and simpler control loop design.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Supply Voltage (Pin 15) | - | - | 40 | V |
| Collector Supply Voltage (Pin 13) | - | - | 40 | V |
| Operating Temperature Range | -40 | - | 85 | °C |
| ESD Ratings (HBM) | - | - | ±2500 | V |
| ESD Ratings (CDM) | - | - | ±1500 | V |
| Reference Voltage Output | 4.95 | 5.1 | 5.25 | V |
| Error Amplifier Input Offset Voltage | 0.5 | - | 10 | mV |
| Output Collector-Emitter Voltage | - | - | 40 | V |
| Output Current (Peak) | - | - | 500 | mA |
Key Features
- Automatic Feedforward Compensation: Enhances line regulation and load response.
- Programmable Pulse-by-Pulse Current Limiting: Provides robust overcurrent protection.
- Automatic Symmetry Correction in Push-Pull Configuration: Ensures balanced operation in push-pull converters.
- Enhanced Load Response Characteristics: Improves the dynamic response of the power supply.
- Parallel Operation Capability: Allows multiple power modules to operate in parallel with equal current sharing.
- Differential Current Sense Amplifier with Wide Common Mode Range: Enables remote and noise-free current sensing.
- Double-Pulse Suppression Protection: Prevents double-pulsing in the output stage.
- Undervoltage Lockout and Soft-Start Capability: Ensures safe startup and shutdown operations.
- Shutdown Terminal: Allows for external shutdown control with latching or automatic restart options.
- ±1% Band Gap Reference: Provides a precise reference voltage for the error amplifier.
Applications
- Telecommunication Power Converters: Suitable for high-reliability power supplies in telecommunication systems.
- Industrial Power Converters: Used in various industrial power conversion applications requiring high efficiency and reliability.
- DC-to-DC Converters: Ideal for fixed-frequency, current-mode controlled DC-to-DC conversion systems.
- Off-Line Power Supplies: Applicable in off-line power supplies that require robust and efficient control mechanisms.
Q & A
- What is the operating temperature range of the UC2846NG4?
The operating temperature range of the UC2846NG4 is -40°C to 85°C.
- What is the maximum supply voltage for the UC2846NG4?
The maximum supply voltage for the UC2846NG4 is 40 V.
- What type of output stage does the UC2846NG4 have?
The UC2846NG4 has a totem pole output stage capable of sourcing or sinking high-peak currents.
- Does the UC2846NG4 support parallel operation of power modules?
Yes, the UC2846NG4 supports parallel operation of power modules with equal current sharing.
- What is the purpose of the differential current sense amplifier in the UC2846NG4?
The differential current sense amplifier allows for remote and noise-free sensing of peak switch current.
- How does the UC2846NG4 handle overcurrent protection?
The UC2846NG4 features programmable pulse-by-pulse current limiting for robust overcurrent protection.
- What is the function of the shutdown terminal in the UC2846NG4?
The shutdown terminal allows for external shutdown control with options for latching or automatic restart.
- What is the accuracy of the band gap reference in the UC2846NG4?
The band gap reference in the UC2846NG4 is trimmed to ±1% accuracy.
- Can the UC2846NG4 be used in telecommunication power converters?
Yes, the UC2846NG4 is suitable for high-reliability power supplies in telecommunication systems.
- What type of ESD protection does the UC2846NG4 have?
The UC2846NG4 has ESD protection rated at ±2500 V (HBM) and ±1500 V (CDM).
