1 Features
1• Smart Power Mode in Factory Default (Compatible
with TI Smart Power Stage CSD95378B and Pin-
for-Pin Equivalent to TPS40425 – Non-Smart
Power Mode in Factory Default)
• Single Supply Operation: 4.5 V to 20 V
• VOUT from 0.6 V
• Dual or Multi-Phase Synchronous Buck Controller
• Individual High-Speed AVS Interface
• Fast Transient Response
• Stackable up to Four Phases
– 2-, 3-, or 4-Phase Interleaved Phase Shifts
– Accurate Current Sharing
• PMBus Interface Capability
– Margining Up/Down with 2-mV Step
– Programmable Fault Limit and Response
– ±0.8% VOUT
– Accuracy Current Monitoring
– ±3°C External Temperature Monitoring In
Smart Power Mode
– Programmable UVLO ON/OFF Thresholds
– Programmable Soft-Start Time, Turn-On
Delay, and Turn-Off Delay
• On-Chip Non-Volatile Memory (NVM) to Store
Custom Configurations
• 0.6-V Reference Voltage with 0.5% Accuracy from
–40°C to 125°C
• Programmable ƒSW from 200 kHz to 1.5 MHz
• Supports Pre-biased Output
• Differential Remote Sensing
• Synchronization to an Extermal Clock
• OC/OV/UV/OT Fault Protection
• 40-Pin, 6 mm × 6 mm, QFN Package

2 Applications
• Wireless Infrastructure
• Switcher/Router Networking/Server/Storage

3 Description
The TPS40428 device is a PMBus, synchronous
buck, driverless controller. It operates in smart power
mode with factory default settings, and it can operate
in non-smart power mode after PMBus programing and power reboot. It can be configured for dual-
output or 2-phase operation. It is also stackable up to
4 phases to support load current as high as 120 A.
Interleaved phase shift for 2-. 3-, or 4-phases reduce the input and output ripples therefore reducing input
and output capacitance.
The wide input voltage range can support 5-V and
12-V intermediate supply buses. The 0.5% reference
voltage satisfies the need of precision voltage to the
modern ASICs.
Using the PMBus standard, the TPS40428 device
can program reference voltage, fault limit, UVLO threshold, soft-start time and turn-on and turn-off
delay.
In addition, the device implements an accurate
measurement system to monitor the output voltages,
currents and temperatures for individual channels.