PMIC with Dual 4A/5A Bucks, One 2A Load Switch, and Input Power Supervisor

The MP5403B from Monolithic Power Systems is a monolithic power management unit containing two high-efficiency, step-down, switching converters and a load switch. The two regulators supply peak currents up to 5A and 4A separately, and the load switch supplies up to 3A of load current with an extremely low RDS(on).

With an input range of up to 6V, the MP5403B is designed for powering ASICs, solid-state drives (SSDs), portable instrumentation, and other compact battery-power devices.

The peak-current-mode control scheme with pulse-skip mode operation provides the two switchers with fast transient response, high light-load efficiency, and a minimal number of capacitors by using an interleaving pwm clock between the two switchers. The 3A load switch with a low 20mΩ on resistance provides flexible system configuration.

Typical application schematic (click on image to enlarge)

A full set of enable control pins and power good open-drain indicators allow for easy implementation of the start-up and shutdown sequences.

Full protection features include over-current protection (OCP) and thermal shutdown.

The MP5403B requires a minimal number of readily available, standard, external components and is available in a small UTQFN-20 (2.5mmx3mm) package.

Features include:

  • Up to 6V Operating Input Range
  • Low IQ: 85µA for Two Switchers Total
  • Two Buck Converters
    • Peak 5A with 55mΩ/20mΩ RDS(on)
    • Peak 4A with 65mΩ/22mΩ RDS(on)
    • 5MHz Switching Frequency
    • 180° Interleaving Operation
    • 100% Duty Cycle
    • Load Switch Mode by Pulling FB Low
    • Latch-Off Short-Circuit Protection (SCP)
    • Internal Soft Start (SS) and Output Discharge
    • Optimized Light-Load Efficiency
  • One Load Switch with 20mΩ RDS(on)
    • 3A with 20mΩ RDS(on)
    • Soft Start (SS) and Output Discharge
    • Over-Current Protection (OCP)
  • EN and Power Good (PG) for Power Sequencing
  • Input Power Good (PG) Indicator with Adjustable Threshold and Delay
  • Thermal Shutdown
Monolithic Power Systems Inc.
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