MPQ8634B
16V, 20A, Sync, Step-Down Converter
with Adjustable Current Limit,
Programmable Frequency, and Voltage Tracking
The Future of Analog IC Technology
20A Output Current
DESCRIPTION
Low RDS(ON) Integrated Power MOSFETs
Proprietary Switching Loss Reduction
Technique
Adaptive COT for Ultrafast Transient
Response
Stable with Zero ESR Output Capacitor
0.5% Reference Voltage over 0°C to
+70°C Junction Temperature Range
1% Reference Voltage from -40°C to
+125°C Junction Temperature Range
Selectable Pulse-Skip Mode or Forced CCM
Operation
The MPQ8634B is a fully integrated, high-
frequency, synchronous, buck converter. The
MPQ8634B offers a very compact solution that
achieves up to 20A output current with excellent
load and line regulation over a wide input
supply range. The MPQ8634B operates at high
efficiency over a wide output current load range.
The
MPQ8634B
adopts
an
internally
compensated constant-on-time (COT) control
mode that provides fast transient response and
eases loop stabilization.
The operating frequency can be set to 600kHz,
800kHz, or 1000kHz easily with MODE
configuration, allowing the MPQ8634B’s
frequency to remain constant regardless of the
input/output voltages.
Excellent Load Regulation
Output Voltage Tracking
Output Voltage Discharge
PGOOD Actively Clamped at a Low Level
during Power Failure
Programmable Soft-Start Time from 1.5ms
Pre-Bias Start-Up
The output voltage start-up ramp is controlled
by an internal 1.5ms timer. It can be increased
by adding a capacitor on TRK/REF. An open-
drain power good (PGOOD) signal indicates
when the output is within its nominal voltage
range. PGOOD is clamped at around 0.7V with
an external pull-up voltage when the input
supply fails to power the MPQ8634B.
Selectable Switching Frequency from
600kHz, 800kHz, and 1000kHz
Non-Latch OCP, UVP, UVLO, Thermal
Shutdown, and Latch-Off for OVP
Output Adjustable from 0.9V to 90%*VIN,
up to 6V Max
Available in
Package
a
QFN-21 (3mmx4mm)
Fully integrated protection features include
over-current protection (OCP), over-voltage
protection (OVP), under-voltage protection
(UVP), and over-temperature protection (OTP).
APPLICATIONS
Telecom and Networking Systems
Servers, Cloud-Computing, Storage
Base Stations
The MPQ8634B requires a minimal number of
readily
available,
standard,
external
components and is available in a QFN-21
(3mmx4mm) package.
General Purpose Point-of-Load (PoL)
12V Distribution Power Systems
High-end TV
FEATURES
Wide Input Voltage Range:
o 2.85V to 16V with External 3.3V VCC
Bias
Game Consoles and Graphic Cards
All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For
MPS green status, please visit the MPS website under Quality
Assurance. “MPS” and “The Future of Analog IC Technology” are registered
trademarks of Monolithic Power Systems, Inc.
o 4V to 16V with Internal VCC Bias or
External 3.3V VCC Bias
Differential Output Voltage Remote Sense
Programmable Accurate Current Limit Level
MPQ8634B Rev. 1.02
11/16/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
1