MPQ86xx Step-Down Converters with Adjustable Curre

By Monolithic Power Systems 245

MPQ86xx Step-Down Converters with Adjustable Curre

Monolithic Power Systems' MPQ86xx series are fully integrated high-frequency, synchronous buck converters. These converters offer a very compact solution that achieves up to 12 A of output current with excellent load and line regulation over a wide input supply range. They operate at high efficiency over a wide output current load range and adopt an internally compensated constant-on-time (COT) control that provides fast transient response and eases loop stabilization. The operating frequency can be set to 600 kHz, 800 kHz, 1,000 kHz, 1,100 kHz, or 2,000 kHz easily with MODE configuration, allowing the MPQ86xx’s frequency to remain constant regardless of the input and output voltages.

The output voltage start-up ramp is controlled by an internal 1.5 ms timer which can be increased by adding a capacitor on TRK/REF. An open-drain power good (PGOOD) signal indicates if the output is within its nominal voltage range. PGOOD is clamped to around 0.7 V with an external pull-up voltage when the input supply fails to power the converter. Full protection features include overcurrent protection (OCP), overvoltage protection (OVP), undervoltage protection (UVP), and overtemperature protection (OTP). The MPQ86xx requires a minimal number of readily available, standard, external components and is available in a multitude of QFN packages.

Block Diagram

  • Wide input voltage range 1.5 V to 18 V
  • 6 A output current
  • Programmable accurate current limit level
  • Low RDS(ON) integrated power MOSFETs
  • Proprietary switching loss reduction technique
  • Adaptive COT for ultra-fast transient response
  • Stable with zero ESR output capacitor
  • 0.5% reference voltage over 0°C to +70°C junction temperature range
  • 1% reference voltage over -40°C to +125°C junction temperature range
  • Selectable forced CCM or pulse-skip operation
  • Excellent load regulation
  • Output voltage tracking
  • Output voltage discharge
  • PGOOD active clamped at low level during power failure
  • Programmable soft-start time from 1.5 ms and up
  • Pre-bias start-up 
  • Selectable switching frequency from 600 kHz, 1,100 kHz, and 2,000 kHz
  • Latch-off for OCP, OVP, UVP, OTP, and UVLO
  • Output adjustable from 0.9 V to 0.9 x VIN up to 6 V max
  • Distribution power systems
  • High-end televisions
  • Game consoles and graphics cards
  • Telecom and networking systems
  • Servers, cloud-computing, and storage
  • Base stations
  • General purpose point-of-load (PoL)