LM2738_15 Datasheet, PDF (1/38 Pages) Texas Instruments – LM2738 550kHz/1.6MHz 1.5A Step-Down DC-DC Switching Regulator

LM2738
www.ti.com
SNVS556B – APRIL 2008 – REVISED APRIL 2013
LM2738 550kHz/1.6MHz 1.5A Step-Down DC-DC Switching Regulator
Check for Samples: LM2738
FEATURES
1
•2 Space Saving WSON and MSOP-PowerPAD
Package
• 3.0V to 20V Input Voltage Range
• 0.8V to 18V Output Voltage Range
• 1.5A Output Current
• 550kHz (LM2738Y) and 1.6MHz (LM2738X)
– Switching Frequencies
• 250mΩ NMOS Switch
• 400nA Shutdown Current
• 0.8V, 2% Internal Voltage Reference
• Internal Soft-Start
• Current-Mode, PWM Operation
• Thermal Shutdown
APPLICATIONS
• Local Point of Load Regulation
• Core Power in HDDs
• Set-Top Boxes
• Battery Powered Devices
• USB Powered Devices
• DSL Modems
DESCRIPTION
The LM2738 regulator is a monolithic, high frequency,
PWM step-down DC/DC converter in an 8-pin WSON
or 8-pin MSOP-PowerPAD package. It provides all
the active functions for local DC/DC conversion with
fast transient response and accurate regulation in the
smallest possible PCB area.
With a minimum of external components, the LM2738
is easy to use. The ability to drive 1.5A loads with an
internal 250mΩ NMOS switch using state-of-the-art
0.5µm BiCMOS technology results in the best power
density available. Switching frequency is internally set
to 550kHz (LM2738Y) or 1.6MHz (LM2738X),
allowing the use of extremely small surface mount
inductors and chip capacitors. Even though the
operating frequencies are very high, efficiencies up to
90% are easy to achieve. External enable is included,
featuring an ultra-low stand-by current of 400nA. The
LM2738 utilizes current-mode control and internal
compensation to provide high-performance regulation
over a wide range of operating conditions. Additional
features include internal soft-start circuitry to reduce
in-rush current, cycle-by-cycle current limit, thermal
shutdown, and output over-voltage protection.
TYPICAL APPLICATION CIRCUIT
Efficiency vs Load Current
V_IN = 12V, V_OUT = 3.3V
V_IN
C1
ON
OFF
V_IN
BOOST
C3
SW
LM2738
D1
EN
FB
GND
D2
L1
R1
R2
V_OUT
C2
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008–2013, Texas Instruments Incorporated