Overview
The UC3525BN is a pulse width modulator (PWM) integrated circuit designed by Texas Instruments. It is part of the UC3525B series, which offers enhanced performance and reduced external component count for designing various switching power supplies. This device features a built-in +5.1V buried zener reference, a sync input for oscillator synchronization, and built-in soft-start circuitry. The UC3525BN is particularly useful in applications requiring precise voltage regulation and control over a wide range of operating conditions.
Key Specifications
| Parameter | Value | Units |
|---|---|---|
| Reference Voltage | 5.062 to 5.138 | V |
| Line Regulation | 5 to 10 | mV |
| Load Regulation | 7 to 15 | mV |
| Temperature Stability | 10 to 50 | mV |
| Oscillator Frequency Range | 100Hz to 400kHz | |
| Oscillator Timing Resistor | 2kΩ to 150kΩ | |
| Oscillator Timing Capacitor | 0.001µF to 0.1µF | |
| Dead Time Resistor Range | 0Ω to 500Ω | |
| Operating Temperature Range | 0°C to 70°C | |
| Input Voltage Range | 8V to 35V |
Key Features
- Built-in +5.1V Buried Zener Reference: Trimmed to ±0.75% for high accuracy.
- Synchronization Capability: Sync input allows multiple units to be slaved or synchronized to an external system clock.
- Soft-Start Circuitry: Requires only an external timing capacitor for smooth startup.
- Shut-Down Terminal: Controls both soft-start circuitry and output stages for instantaneous turn-off and soft-start recycle.
- Adjustable Dead Time: Single resistor between CT and discharge terminals for wide range of dead time adjustment.
Applications
The UC3525BN is suitable for a variety of switching power supply applications, including:
- DC-DC Converters: High-efficiency power conversion in DC-DC converters.
- SMPS (Switch-Mode Power Supplies): Used in various SMPS designs requiring precise voltage regulation.
- Power Management Systems: Integrated into power management systems for reliable and efficient power delivery.
Q & A
- What is the operating temperature range of the UC3525BN?
The UC3525BN operates within a temperature range of 0°C to 70°C. - What is the input voltage range for the UC3525BN?
The input voltage range is from 8V to 35V. - What is the oscillator frequency range of the UC3525BN?
The oscillator frequency range is from 100Hz to 400kHz. - Does the UC3525BN have built-in soft-start circuitry?
Yes, it has built-in soft-start circuitry that requires only an external timing capacitor. - How can the dead time be adjusted in the UC3525BN?
The dead time can be adjusted using a single resistor between the CT and discharge terminals. - What is the purpose of the sync input in the UC3525BN?
The sync input allows multiple units to be slaved or synchronized to an external system clock. - What is the reference voltage of the UC3525BN?
The reference voltage is 5.1V, trimmed to ±0.75%. - Can the UC3525BN be used in DC-DC converters?
Yes, it is suitable for use in DC-DC converters and other switching power supply applications. - How does the shut-down terminal function in the UC3525BN?
The shut-down terminal controls both the soft-start circuitry and the output stages, allowing for instantaneous turn-off and soft-start recycle. - What is the package type of the UC3525BN?
The UC3525BN is available in a PDIP (N) package with 16 pins.
