36V, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter Draws Quiescent Current of Only 75uA

News Release ⎜ www.linear.com
36V, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter
Draws Quiescent Current of Only 75uA
MILPITAS, CA – August 14, 2007 – Linear Technology Corporation announces the LT3680, a
3.5A, 36V step-down switching regulator with Burst Mode® operation to keep quiescent current
under 75uA. The LT3680 operates within a VIN range of 3.6V to 36V, making it ideal for load
dump and cold-crank conditions found in automotive applications. Its 4.6A internal switch can
deliver up to 3.5A of continuous output current to voltages as low as 0.79V. The LT3680’s Burst
Mode operation offers ultra-low quiescent current, well suited for applications such as
automotive or telecom systems, which demand always-on operation and optimum battery life.
Switching frequency is user programmable from 250kHz to 2.4MHz, enabling the designer to
optimize 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 LT3680 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 LT3680 enable high efficiency over a wide
input voltage range, and the devices’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 LT3680EDD and LT3680EMSE starts at $4.15 and $4.25 each,
respectively for 1,000-piece quantities. The LT3680IDD and LT3680IMSE are tested and
guaranteed to operate from a -40°C to 125°C operating junction temperature, priced at $4.98 and
$5.10 each, respectively in 1,000-piece quantities. All versions are available from stock.
36V, 3.5A(IOUT), 2.4MHz Step-Down DC/DC Converter
Draws Quiescent Current of Only 75uA
page 2
Photo Caption: 36V, 3.5A Step Down with Only 75uA Quiescent Current
Summary of Features: LT3680
Wide Input Range: 3.6V to 36V
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: 95m Ohm On-Resistance
0.790V Feedback Reference Voltage
Output Voltage: 0.79V to 30V
Thermal Protection
Soft-Start Capability
Small 10-Pin Thermally Enhanced MSOP & (3mm × 3mm) DFN Package
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, 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 of Linear Technology Corp.
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