Overview
The UC3846NG4 is a current-mode PWM controller produced by Texas Instruments. It is part of the UC3846 family, which is designed for fixed-frequency, current-mode control schemes in power conversion applications. This controller is known for its high performance, minimal external component requirements, and robust feature set, making it suitable for a variety of power supply designs.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage | VCC | - | - | 30 | V |
| Output Current | IO | - | - | ±1 | A |
| Reference Output Voltage | VREF | 4.90 | 5.00 | 5.10 | V |
| Oscillation Frequency | f | 47 | 52 | 57 | kHz |
| Low Output Voltage | VOL | - | 0.08 | 0.4 | V (ISINK = 20mA) |
| High Output Voltage | VOH | 13 | 13.5 | - | V (ISOURCE = 20mA) |
| Rise Time | tR | - | 45 | 150 | ns (CL = 1nF) |
| Fall Time | tF | - | 35 | 150 | ns (CL = 1nF) |
| Start Threshold Voltage | VTH(ST) | 14.5 | 16.0 | 17.5 | V |
| Minimum Operating Voltage | VOPR(MIN) | 8.5 | 10.0 | 11.5 | V |
Key Features
- Automatic Feedforward Compensation: Enhances line regulation and load response characteristics.
- Programmable Pulse-by-Pulse Current Limiting: Provides inherent current limiting capability on a pulse-by-pulse basis.
- Automatic Symmetry Correction in Push-Pull Configuration: Ensures balanced operation in push-pull converters.
- Enhanced Load Response Characteristics: Improves the controller's ability to handle load changes.
- 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-pulse occurrences.
- Undervoltage Lockout (UVLO) with Hysteresis: Protects the device from operating below the minimum voltage threshold.
- Soft-Start Capability: Gradually increases the output voltage to prevent inrush currents.
- Shutdown Terminal: Allows for remote shutdown and restart functions.
- ±1% Band Gap Reference: Provides a stable reference voltage.
- 500-mA (Peak) Totem-pole Outputs: High current drive capability for power MOSFETs.
Applications
- Telecommunication Power Converters: Suitable for high-reliability power supplies in telecommunications equipment.
- Industrial Power Converters: Used in various industrial power conversion applications requiring high performance and reliability.
- Off-Line and DC to DC Converters: Designed for use in both off-line and DC to DC converter applications with minimal external components.
Q & A
- What is the UC3846NG4 used for?
The UC3846NG4 is a current-mode PWM controller used in power conversion applications such as telecommunication and industrial power supplies.
- What are the key features of the UC3846NG4?
Key features include automatic feedforward compensation, programmable pulse-by-pulse current limiting, automatic symmetry correction, and parallel operation capability among others.
- What is the maximum supply voltage for the UC3846NG4?
The maximum supply voltage is 30V.
- What is the typical oscillation frequency of the UC3846NG4?
The typical oscillation frequency is 52 kHz.
- Does the UC3846NG4 have undervoltage lockout (UVLO) protection?
Yes, it includes UVLO with hysteresis to protect the device from operating below the minimum voltage threshold.
- What is the purpose of the shutdown terminal on the UC3846NG4?
The shutdown terminal allows for remote shutdown and restart functions.
- Can the UC3846NG4 operate in parallel with other power modules?
Yes, it has the capability for parallel operation with equal current sharing.
- What is the typical reference output voltage of the UC3846NG4?
The typical reference output voltage is 5.00V.
- Does the UC3846NG4 have soft-start capability?
Yes, it includes soft-start capability to prevent inrush currents during startup.
- What are the common package types for the UC3846NG4?
Common package types include PDIP (16-pin), SOIC (16-pin), and PLCC (20-pin).
