LT1108CS8-5#PBF

PMIC - Voltage Regulators - DC DC Switching Regulators

LT1108CS8-5#PBF is a switching regulator which offers efficient and reliable power supplies for challenging applications.

Application Field

LT1108CS8-5#PBF is suitable for switching power supplies used in electronic equipment such as battery-powered applications, set-top boxes, fax machines and routers, and can be used as:

• Positive buck regulator
• Negative buck/boost regulator
• Negative SEPIC regulator
• Inverting regulator

The device is suitable for applications requiring positive output voltages up to 10V, negative output voltages down to –10V, and adjustable output voltages over a wide range.

Working Principle

LT1108CS8-5#PBF is a voltage mode, single - inductor/dual - switch (SIDs) switching regulator. It operates with a fixed oscillator frequency of 2.5MHz and features programmable soft-start and current limit functions.The device contains a high-side and low-side N-channel power MOSFET. The high-side MOSFET switches at the peak of the inductor current waveform while the low-side MOSFET switches at the bottom of the waveform. The voltage at the FB pin is compared to an internal reference voltage to determine the duty cycle of the MOSFETs.

The switching regulator will maintain the output voltage at the FB pin by controlling the duty cycle of the switches to ensure that a constant output voltage is produced. The current limit comparator will compare the voltage at the FB pin to the voltage at the ISEN pin, and control the current limit by controlling the duty cycle of the switches.

Conclusion

LT1108CS8-5#PBF is a high-performance, energy-efficient switching regulator which can be used in a range of applications requiring positive or negative output voltage.

It is suitable for applications requiring output voltages up to 10V and features programmable soft-start and current limit functions.