Overview
The SG3525ANG, produced by onsemi, is a pulse width modulator (PWM) controller designed to offer improved performance and a lower external parts count for controlling various types of switching power supplies. This device features an on-chip +5.1 V reference voltage trimmed to ±1%, eliminating the need for external divider resistors. It includes a sync input to the oscillator, allowing multiple units to be slaved or synchronized to an external system clock. The SG3525ANG also incorporates built-in soft-start circuitry, adjustable deadtime control, and input undervoltage lockout, making it versatile for a range of power supply applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage (VCC) | 8.0 to 35 | V |
| Reference Voltage | 5.1 ± 1.0% | V |
| Oscillator Frequency Range | 100 Hz to 400 kHz | |
| Output Current, Source or Sink | ±500 mA | mA |
| Reference Output Current | 50 mA | mA |
| Oscillator Charging Current | 5 mA | mA |
| Power Dissipation at Tamb = 70 °C | 1000 mW | mW |
| Junction Temperature Range | -55 to 150 °C | °C |
| Storage Temperature Range | -65 to 150 °C | °C |
| Operating Ambient Temperature | 0 to 85 °C | °C |
Key Features
- 8.0 V to 35 V operation range
- 5.1 V ± 1.0% trimmed reference voltage
- 100 Hz to 400 kHz oscillator range
- Separate oscillator sync pin for synchronization with external clocks
- Adjustable deadtime control using a single resistor
- Built-in soft-start circuitry requiring only an external timing capacitor
- Input undervoltage lockout with hysteresis
- Latching PWM to prevent multiple pulses
- Pulse-by-pulse shutdown and soft-start recycle
- Dual source/sink output drivers capable of ±400 mA peak current
- Totem-pole output stage design
- Pb-free packages available
Applications
The SG3525ANG is suitable for a wide range of switching power supply applications, including:
- Half-bridge and push-pull configurations
- Single-ended and multiple-phase power supplies
- Low power transformers and power FETs
- General-purpose switching power supplies requiring high performance and reliability
Q & A
- What is the operating voltage range of the SG3525ANG?
The SG3525ANG operates within a voltage range of 8.0 V to 35 V.
- What is the accuracy of the on-chip reference voltage?
The on-chip reference voltage is trimmed to ±1%.
- What is the oscillator frequency range of the SG3525ANG?
The oscillator frequency range is from 100 Hz to 400 kHz.
- How is the deadtime controlled in the SG3525ANG?
The deadtime can be programmed using a single resistor connected between the CT and Discharge pins.
- What type of output stage does the SG3525ANG feature?
The output stage is a totem-pole design capable of sinking and sourcing in excess of 200 mA.
- Does the SG3525ANG have built-in soft-start circuitry?
- How does the shutdown pin function in the SG3525ANG?
The shutdown pin controls both the soft-start circuitry and the output stages, providing instantaneous turn-off and soft-start recycle.
- What is the purpose of the input undervoltage lockout?
The input undervoltage lockout inhibits the outputs and the changing of the soft-start capacitor when VCC is below nominal.
- Can the SG3525ANG drive low power transformers directly?
- Is the SG3525ANG available in Pb-free packages?
