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LM25117, LM25117-Q1
SNVS714F – APRIL 2011 – REVISED AUGUST 2015
LM25117/Q1 Wide Input Range Synchronous Buck Controller With Analog Current Monitor
1 Features
•1 LM25117-Q1 is Qualified for Automotive Applications
• AEC-Q100 Qualified With the Following Results: – Device Temperature Grade 1: -40°C to 125°C Ambient Operating Temperature Range
• Emulated Peak Current Mode Control • Wide Operating Range from 4.5 V to 42 V • Robust 3.3 A Peak Gate Drives • Adaptive Dead-time Output Driver Control • Free-run or Synchronizable Clock up to 750 kHz • Optional Diode Emulation Mode • Programmable Output from 0.8 V • Precision 1.5% Voltage Reference • Analog Current Monitor • Programmable Current Limit • Hiccup Mode Over Current Protection • Programmable Soft-start and Tracking • Programmable Line Undervoltage Lockout • Programmable Switch-over to External Bias
Supply • Thermal Shutdown
2 Applications
• Automotive Infotainment • Industrial DC-DC Motor Drivers • Automotive USB Power • Telecom Server
3 Description
The LM25117 is a synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-bycycle current limiting and ease of loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high input voltage applications.
The operating frequency is programmable from 50 kHz to 750 kHz. The LM25117 drives external highside and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions. A high voltage bias regulator that allows external bias supply further improves efficiency. The LM25117’s unique analog telemetry feature provides average output current information. Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM25117
HTSSOP (20) PWP 6.50 mm x 4.40 mm
LM25117-Q1
WQFN (24) RTW 4.00 mm x 4.00 mm
(1) For all available packages, see the orderable addendum at the end of the datasheet.
Typical Application
VIN
SW VOUT
UVLO VIN DEMB VCC
RAMP
HB
LM25117
HO VCCDIS
SW
COMP FB CM
LO CS CSG
RT RES SS AGND PGND
VOUT
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA.
LM25117, LM25117-Q1
SNVS714F – APRIL 2011 – REVISED AUGUST 2015
www.ti.com
Table of Contents
1 Features ...........................