The SC1185 is a 3.3V switching power supply chip from SEMTECH. It has a built-in 5-bit D/A converter that can be used to adjust the output voltage from 2.0V to 3.5V in 100mV increments. It also has overcurrent protection and soft-start functionality. The chip also includes two low-dropout linear regulators that can provide 1.5V and 2.5V for GTL buses and non-GTL I/O, respectively.
The SC1185 combines a synchronous voltage mode controller with two low-dropout linear regulators to implement three DC/DC converters. The switching section operates at a fixed frequency of 140kHz and features an integrated 5-bit D/A converter for programmable output voltages ranging from 2.0V to 3.5V without external components.
The device includes the SC1185A variant which provides improved output tolerance. Key electrical characteristics include a supply current of 8-15 mA, an oscillator frequency range of 125 kHz to 160 kHz, and typical efficiencies up to 95% for the switching section.
| Oscillator Frequency | 125 kHz to 160 kHz (Typ: 140 kHz) |
|---|---|
| Supply Current | 8 mA to 15 mA |
| Output Voltage Range (Switching) | 2.0V to 3.5V in 100mV increments |
| Operating Temperature Range | 0°C to +125°C |
| Efficiency (Switching Section) | 95% |
The switching section operates at a fixed frequency of 140kHz.
No, it provides programmability with no external components required.