LM2679SDX-12 Datasheet/PDFLM2679SDX-12 Voltage Regulator
The LM2679SDX-12 voltage regulator from Texas Instruments is a synchronous step down DC to DC switching regulator. It’s a member of TI’s wide range of high efficiency Power Management Integrated Circuit (PMIC) voltage regulators, designed for applications requiring extended output current and voltage ranges such as powering FPGAs and microprocessors from 5V to 0.6V.
Features
- 1A Peak output current
- Automatic power-on-reset switching frequency
- Built-in soft-start
- Cycle-by-cycle current limiting
- ±1.5% output voltage accuracy over full temperature range
- Reverse-battery protection
- Internal MOSFET power switch
- High efficiency up to 93%
The LM2679SDX-12 is versatile with 3-pins adjustable operating frequency, and is simple to use with cycle-by-cycle over current protection and thermal shutdown. Operating temperature range is from -40°C to 125°C.
Applications
- FPGA and microprocessor power supplies
- High current DC to DC transduction and conversion
- High current linear and switching power supplies
- Battery charger circuits
- Basic power supply and voltage regulator circuits
Working Principle
The LM2679SDX-12 synchronous step down DC-DC switching regulator works by controlling the duty cycle of its internal switching MOSFETs to regulate the output voltage. It consists of a high-side MOSFET and a low-side MOSFET in series, with the high-side being controlled by the on-chip oscillator. The frequency of the oscillator is set by the external capacitors.
When the high-side MOSFET is turned on, current flows from the input to the output and through the low-side MOSFET. When the high-side MOSFET is turned off, the low-side MOSFET acts as a body diode, allowing the current to continue to flow from the input to the output. In this way, the output voltage is regulated by controlling the duty cycle of the high-side MOSFET.
The LM2679SDX-12 also features an internal soft-start circuit, which prevents inrush current during startup and reduces output voltage overshoot. It also features an on-chip over current protection circuit and a thermal shutdown circuit to protect it from exceeding its maximum operating temperature.
The LM2679SDX-12 is an ideal solution for applications requiring high accuracy output voltage regulation with an extended output current and voltage range. Its small size and high efficiency make it a great choice for high current DC-DC converters and battery chargers.