1 Features
• Efficiency up to 95% for each switching regulator
• Switching regulator specifications:
– Input voltage range: 4.5 to 18 V
– VOUT range: 0.6 V-90%VIN
– SW1, SW2 IOUT: 4-A max
– SW3, SW4 IOUT: 2-A max
• Prebias start-up algorithm minimizes voltage dip
during start-up
• Internal undervoltage lockout (UVLO), overcurrent
protection (OCP), overvoltage protection (OVP),
and overtemperature protection (OTP)
• AECQ-100 grade 1 option
• Thermally enhanced 7-mm × 7-mm 48-pin, 0.5-mm
pitch VQFN package
• Pin accessible features:
– Adjustable VOUT with external feedback
resistors
– Sequencing control through precision enable
pins for each switcher
– Resistor adjustable PWM switching frequency
from 275 kHz to 2.2 MHz
– Clock sync input and clock output
– Soft-start delay through external capacitor
– Current sharing between SW1 and SW2 and
between SW3 and SW4 allows support of
higher current needs if required
• PMBus runtime control and status
– Runtime voltage positioning through adjustment
of VREF
– Enable and disable of each switcher
– Fault and status monitoring
• User-configurable PMBus/I2C options, saved in
EEPROM
– Power supply turn-on and turn-off sequencing
– Sequencing can be based on fixed time delays
or PGOOD dependence
– Initial voltage positioning through VREF
configuration
– PWM frequency adjustment for each switcher
– Individual PWM phase alignment for each
switcher to minimize ripple and capacitor size
– Adjustable current limit on each regulator
enables size and cost optimization of inductors
– Soft-start time

2 Applications
• Small cellular base stations (BTS) (for example:
picocells and microcells); macro BTS (using
multiple PMUs)
• Power over ethernet (PoE) powered
communications infrastructure equipment
• Automotive infotainment and telematics
• Powering DSP and MCUs
• Industrial and factory automation
• Systems requiring small form factor, highefficiency,
high-ambient operating temperature,
and flexible power management

3 Description
The TPS65400 is an integrated PMU optimized for
applications requiring small form factor and high
power conversion efficiency, enabling small spaceconstrained
equipment with high ambient operating
temperature without cooling. The device provides
high-power efficiency at a system level by enabling
a single stage conversion from an intermediate
distribution bus with an optimized combination of
regulators.