LM73605_17 Datasheet, PDF (1/53 Pages) Texas Instruments – LM73605/LM73606 3.5-V to 36-V, 5-A or 6-A Synchronous Step-Down Voltage Converter

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LM73605, LM73606
SNVSAH5 – SEPTEMBER 2017
LM73605/LM73606 3.5-V to 36-V, 5-A or 6-A Synchronous
Step-Down Voltage Converter
1 Features
•1 Synchronous Rectification
• Wettable Flanks QFN Package (WQFN)
• Low Quiescent Current
– 0.8 µA in Shutdown (typical)
– 15 µA in Active Mode with No Load (typical)
• Wide Voltage Conversion Range:
– t_{ON_MIN} = 60 ns (typical)
– t_{OFF_MIN} = 70 ns (typical)
• Low MOSFET ON-Resistance:
– R_{DS_ON_HS} = 53 mΩ (typical)
– R_{DS_ON_LS} = 31 mΩ (typical)
• External Bias Input to Improve Efficiency
• Pin-Selectable Auto Mode or Forced PWM
Operation
• Adjustable Frequency Range: 350 kHz to 2.2 MHz
• Synchronizable to External Clock
• Internal Compensation
• Power-Good Flag
• Precision Enable to Program System UVLO
• Flexible Soft-Start Features:
– Start-up into Pre-Biased Load
– Fixed or Adjustable Soft-Start Time
– Output Voltage Tracking
• Cycle-by-Cycle Current Limiting
• Short-Circuit Protection With Hiccup Mode
• Thermal Shutdown Protection
• Create a Custom Design With the WEBENCH^®
Power Designer using LM73605 or LM73606
2 Applications
• Industrial Distributed Power Applications
• Telecommunications Systems
• General-Purpose Wide V_IN Regulation
3 Description
The LM73605/LM73606 family of devices are easy-
to-use synchronous step-down DC-DC converters
capable of driving up to 5 A (LM73605) or 6 A
(LM73606) of load current from a supply voltage
ranging from 3.5 V to 36 V. The LM73605/LM73606
provide exceptional efficiency and output accuracy in
a very small solution size. Peak current-mode control
is employed. Additional features such as adjustable
switching frequency, synchronization to an external
clock, FPWM option, power-good flag, precision
enable, adjustable soft start, and tracking provide
both flexible and easy-to-use solutions for a wide
range of applications. Automatic frequency foldback
at light load and optional external bias improve
efficiency over the entire load range. The family
requires few external components and has a pinout
designed for simple PCB layout with optimal EMI and
thermal performance. Protection features include
thermal shutdown, input undervoltage lockout, cycle-
by-cycle current limiting, and hiccup short-circuit
protection. The LM73605 and LM73606 devices are
pin-to-pin compatible for easy current scaling.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM73605
LM73606
WQFN (30)
Wettable Flanks
6.00 mm × 4.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
VIN
CIN
CVCC
Simplified Schematic
PVIN
EN
PGND
SW
CBOOT
L
CBOOT
VOUT
COUT
PGOOD
BIAS
SS/TRK
SYNC/
MODE
VCC
RT
FB
AGND
RFBT
RFBB
Copyright © 2017, Texas Instruments Incorporated
Efficiency vs Load Current
V_OUT = 5 V, f_SW = 500 kHz, Auto Mode
100
95
90
85
80
75
70
65
60
VIN = 12 V
55
VIN = 24 V
50
0.001
0.01 0.02 0.05 0.1 0.2 0.5 1 2 3 4 56
Load Current (A)
Eff_
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.