1 Features
• New, similar products available:
– LM5145 75-V synchronous buck controller with
wide input voltage and duty cycle ranges
– LM5146 100-V synchronous buck DC/DC
controller with wide duty-cycle range
• Wide input voltage range from 4.5 V to 60 V
• Reference voltage of 600 mV with 1% accuracy
• Programmable UVLO and hysteresis
• Voltage mode control with voltage feed forward
• Programmable frequency between 100 kHz and
600 kHz
• Bi-directional -frequency synchronization with
primary and secondary option
• Low-side FET sensing overcurrent protection and
high-side FET sensing short-circuit protection with
integrated thermal compensation
• Programmable closed loop soft-start
• Supports pre-biased outputs
• Thermal shutdown at 165°C with hysteresis
• Voltage tracking
• Power good
• ENABLE with 1-μA low current shutdown
• LDO output of 8.0 V and 3.3 V
• Integrated Bootstrap Diode
• 20-Pin 3.5 mm × 4.5 mm VQFN (RGY) package
• Create a Custom Design with WEBENCH® Tools

2 Applications
• POL modules
• Wide input voltage, high-power density DC - DC
converters for industrial, networking, and telecom
equipment

3 Description
TPS40170 is a full-featured, synchronous PWM
buck controller that operates at an input voltage
between 4.5 V and 60 V and is optimized for
high-power density, high-reliability DC-DC converter
applications. The controller implements voltage-mode
control with input voltage feed-forward compensation
that enables instant response to input voltage change.
The switching frequency is programmable from 100
kHz to 600 kHz.
The TPS40170 has a complete set of
system protection and monitoring features such
as programmable undervoltage lockout (UVLO),
programmable overcurrent protection (OCP) by
sensing the low-side FET, selectable short-circuit
protection (SCP) by sensing the high-side FET and
thermal shutdown. The ENABLE pin allows for system
shutdown in a low-current (1 μA typical) mode. The
controller supports pre-biased output, provides an
open-drain PGOOD signal, and has closed-loop softstart,
output voltage tracking and adaptive dead-time
control.
TPS40170 provides accurate output voltage
regulation through 1% ensured accuracy. Additionally,
the controller implements a novel scheme of bidirectional
synchronization with one controller acting
as the primary and other downstream controllers
acting as secondaries synchronized to the primary
in-phase or 180° out-of-phase. Secondary controllers
can be synchronized to an external clock within ±30%
of the free-running switching frequency.
New products (LM5145 and LM5146) offer reduced
BOM cost, higher efficiency, and reduced design size
among many other features.