Overview
The UC3825NG4 is a high-speed PWM (Pulse Width Modulation) controller IC produced by Texas Instruments. This device is part of the UC1825 family, which is optimized for high-frequency switched-mode power supply applications. The UC3825NG4 is designed to operate in either current-mode or voltage-mode systems and features advanced protection and control mechanisms. Although the UC1825 family has been discontinued, the UC3825NG4 remains a significant component in legacy and specific high-performance power supply designs.
Key Specifications
| Parameter | Test Conditions | UC3825 | Units |
|---|---|---|---|
| Supply Voltage | Pins 13, 15 | 0 to 30V | V |
| Reference Section Output Voltage | TO = 25°C, IO = 1mA | 5.00 to 5.20 | V |
| Line Regulation | 10V < VCC < 30V | 2 to 20 | mV |
| Load Regulation | 1mA < IO < 10mA | 5 to 20 | mV |
| Temperature Stability | TMIN < TA < TMAX | 0.2 to 0.4 | mV/°C |
| Propagation Delay to Output | 50 to 80 | ns | |
| Output Current, Source or Sink | Pins 11, 14 | 0.5A DC | A |
| Start Up Current | VCC = 8V | 1.1 to 2.5 | mA |
| Operating Temperature Range | 0°C to 70°C | °C |
Key Features
- Compatible with voltage or current mode topologies
- Practical operation switching frequencies up to 1 MHz
- 50 ns propagation delay to output
- High current dual totem pole outputs (1.5 A peak)
- Wide bandwidth error amplifier
- Fully latched logic with double pulse suppression
- Pulse-by-pulse current limiting
- Soft start / maximum duty cycle control
- Under-voltage lockout with hysteresis
- Low start-up current (1.1 mA)
Applications
The UC3825NG4 is optimized for high-frequency switched-mode power supply applications, including:
- High-frequency DC-DC converters
- Power supplies for high-performance electronics
- Switch-mode power supplies requiring high reliability and efficiency
- Current-mode and voltage-mode control systems
Q & A
- What is the operating temperature range of the UC3825NG4?
The operating temperature range of the UC3825NG4 is 0°C to 70°C.
- What is the maximum switching frequency of the UC3825NG4?
The UC3825NG4 can operate at switching frequencies up to 1 MHz.
- What is the propagation delay to output of the UC3825NG4?
The propagation delay to output is between 50 ns and 80 ns.
- Does the UC3825NG4 support both voltage and current mode topologies?
- What is the peak output current of the UC3825NG4?
The UC3825NG4 has high current dual totem pole outputs with a peak current of 1.5 A.
- What protection features does the UC3825NG4 include?
The UC3825NG4 includes features such as pulse-by-pulse current limiting, soft start, maximum duty cycle control, and under-voltage lockout with hysteresis.
- What is the start-up current of the UC3825NG4?
The start-up current of the UC3825NG4 is between 1.1 mA and 2.5 mA at VCC = 8V.
- Is the UC3825NG4 RoHS compliant?
- What is the package type of the UC3825NG4?
The UC3825NG4 is available in PDIP (N) package.
- Why is careful attention to layout and component placement necessary for the UC3825NG4?
Careful attention to layout and component placement is necessary to assure proper performance, particularly to manage parasitic inductive kick energy and ensure proper grounding.
