MPQ8643

MPQ8643

16V, 20A, Configurable-Frequency, Synchronous Step-Down Converter with Adjustable Current Limit and Voltage Tracking

Datasheet

Description

The MPQ8643 is a fully integrated, high-frequency, synchronous step-down converter. It offers a very compact solution that can achieve up to 20A of output current (I_OUT) across a wide input voltage (V_IN) range, with excellent load and line regulation. The MPQ8643 operates at high efficiency across a wide I_OUT load range.

Internally compensated constant-on-time (COT) control provides fast transient response and eases loop stabilization. The selectable switching frequency (f_SW) can be set to 600kHz, 800kHz, or 1000kHz by configuring the MODE pin. This maintains a constant f_SW, regardless of V_IN and the output voltage (V_OUT).

During start-up, the internal soft-start timer (t_SS) (1ms) ramps up V_OUT in a controlled manner. t_SS can be increased by adding a capacitor on the TRK/REF pin. An open-drain power good (PG) signal indicates whether V_OUT is within its nominal voltage range. If the input fails to supply power to the MPQ8643, then the PG voltage (V_PG) is clamped at about 0.7V via an external pull-up voltage.

Fully integrated protection features include over-current protection (OCP), over-voltage protection (OVP), under-voltage protection (UVP), and over-temperature protection (OTP).

The MPQ8643 requires a minimal number of readily available, standard external components, and is available in a QFN-21 (3mmx4mm) package.

Features & Benefits

Wide Input Voltage (V_IN) Range:
- 2.7V to 16V with External 3.3V Bias
- 4V to 16V with Internal Bias or External 3.3V Bias
Differential Output Remote Sense
Configurable Accurate Current Limit (I_LIMIT)
20A Output Current (I_OUT)
Integrated Low R_DS(ON) Power MOSFETs
Proprietary Switching Loss Reduction Technique
Adaptive Constant-On-Time (COT) Control for Ultra-Fast Transient Response
Stable with Zero-ESR Output Capacitor
Reference Voltage (V_REF) Accuracy:
- 0.5% V_REF Accuracy from 0°C to 70°C
- 1% V_REF Accuracy from -40°C to +125°C
Selectable Pulse-Skip Mode (PSM) or Forced Continuous Conduction Mode (FCCM)
Excellent Load Regulation
Output Voltage (V_OUT) Tracking and Discharge
PGOOD Clamped Low during Power Failure
Configurable Soft-Start Time (t_SS) from 1ms
Pre-Biased Start-Up
600kHz, 800kHz, or 1000kHz Selectable Switching Frequency (f_SW)
Non-Latch Over-Current Protection (OCP), Under-Voltage Protection (UVP), Under-Voltage Lockout (UVLO), and Thermal Shutdown
Over-Voltage Protection (OVP) with Latch-Off Mode
Adjustable Output from 0.6V to 90% of V_IN (5.5V Max)
Available in a QFN-21 (3mmx4mm) Package