33VIN, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter Draws Only 75uA of Quiescent Current & Withstands 62V Transients

News Release ⎜ www.linear.com
33VIN, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter Draws Only
75uA of Quiescent Current & Withstands 62V Transients
MILPITAS, CA – October 2, 2008 – Linear Technology Corporation announces the LT3972, a
3.5A, 33VIN step-down switching regulator with Burst Mode® operation to keep quiescent
current under 75uA. The LT3972 operates within a VIN range of 3.6V to 33V, with overvoltage
lockout protection against transients as high as 62V, making it ideal for load dump and
cold-crank conditions commonly found in automotive applications. Its internal 4.6A switch can
deliver up to 3.5A of continuous output current at voltages as low as 0.79V. Its Burst Mode
operation provides ultra-low quiescent current, well suited for applications such as automotive or
telecom systems, which have always-on circuits and need to optimize battery life. Switching
frequency is user programmable from 200kHz to 2.4MHz, enabling the designer to maximize
efficiency while avoiding critical noise-sensitive frequency bands. Its 3mm x 3mm DFN-10
package (or thermally enhanced MSOP-10E) and high switching frequency keep external
inductors and capacitors small, providing a compact, thermally efficient footprint.
The LT3972 utilizes a high efficiency 4.6A, 95mOhm switch, with the necessary boost
diode, oscillator, control and logic circuitry integrated into a single chip. Low ripple Burst Mode
operation maintains high efficiency at low output currents while keeping output ripple below
15mVPK-PK. Special design techniques used in the LT3972 enable high efficiency over a wide
input voltage range, and the device’s current mode topology enables fast transient response and
excellent loop stability. Other features include external synchronization (from 250kHz to 2MHz),
a power good flag and soft-start capability.
Pricing for the LT3972EDD and LT3972EMSE starts at $4.25 and $4.35 each,
respectively for 1,000-piece quantities. The LT3972IDD and LT3972IMSE are guaranteed to
33VIN, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter Draws Only
75uA of Quiescent Current & Withstands 62V Transients
page 2
operate from a -40°C to 125°C operating junction temperature, priced at $5.10 and $5.22 each,
respectively in 1,000-piece quantities. All versions are available from stock.
Photo Caption: 33VIN, 62V Transient Protection Buck Regulator
Summary of Features: LT3972
Wide Input Range:
Operation from 3.6V to 33V
Overvoltage Lockout Protects Circuits Through 62V Transients
3.5A Maximum Output Current
Low Ripple (<15mVP-P) Burst Mode® Operation:
IQ = 75uA at 12VIN to 3.3VOUT
Adjustable Switching Frequency: 200kHz to 2.4MHz
Low Shutdown Current: IQ < 1uA
Integrated Boost Diode
Synchronizable Between 250kHz to 2MHz
Power Good Flag
Saturating Switch Design: 95mOhm On-Resistance
Output Voltage: 0.79V to 30V
Thermal Protection
Soft-Start Capability
Small 10-Pin Thermally Enhanced MSOP & (3mm × 3mm) DFN Packages
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981,
became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear
Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear
regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal
conditioning circuits, uModule™ products, and many other analog functions. Applications for Linear Technology’s
high performance circuits include telecommunications, cellular telephones, networking products such as optical
switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation,
security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex
medical devices, automotive electronics, factory automation, process control, and military and space systems. For
more information, visit www.linear.com.
LT, LTC, LTM, Burst Mode and
are registered trademarks and uModule is a trademark of Linear Technology
Corp. All other trademarks are the property of their respective owners.
Press Contacts:
John Hamburger, Director Marketing Communications
[email protected]
Tel: 408-432-1900 ext 2419
Doug Dickinson, Media Relations Manager
[email protected]
Tel: 408-432-1900 ext 2233