LTC3857EGN-1#PBF

LTC3857-1 is a high performance dual step-down switching regulator controller. It drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of upto 850KHz. Power loss and noise due to the ESR of the input capacitor ESR are minimized by operating the two controller output stages out of phase. Independent TRACK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads. It is widely used in application such as automotive always-on systems, battery operated digital devices, distributed DC power systems etc.

• Input supply operating voltage range is 4V to 38V
• Low operating current is 50μA typ at (RUN1 = 5V and RUN2 = 0V, VFB1 = 0.83V, no load)
• RSENSE or DCR current sensing, no current foldback during start-up
• OPTI-LOOP® compensation minimizes COUT
• Adjustable output voltage soft-start or tracking
• Power good output voltage monitor, output overvoltage protection
• Internal LDO powers gate drive from VIN or EXTVCC
• Shutdown current is 8μA typical at (RUN1,2 = 0V, TA = 25°C)
• Operating junction temperature is -40°C to 125°C
• Package style is 28-lead plastic SSOP

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party