90V Boost DC/DC Converter with APD Current Monitor

News Release  www.linear.com
90V Boost DC/DC Converter with APD Current Monitor
MILPITAS, CA – February 8, 2007 – Linear Technology announces the LT3482, a fixed
frequency, current mode step-up DC/DC converter with a built-in voltage doubler designed to
bias avalanche photodiodes (APDs) in optical receivers. The device can deliver an output of up
to 90V from inputs ranging from 2.5V to 16V. The LT3482 features high side APD current
monitoring, which offers better than 10% relative accuracy over a -40°C to 85°C temperature
range. The integrated power switch, Schottky diodes, and APD current monitor are all on a single
die, packaged in a tiny 3mm x 3mm QFN, providing a tiny solution footprint.
The LT3482’s internal 48V, 280mA switch uses a voltage doubler to deliver voltages as
high as 90V. A constant frequency architecture is used to minimize switching noise and is user
selectable at either 625kHz or 1.1MHz. Low output ripple, critical in APD applications, is
maintained under 80uVPK-PK without any additional filtering. The integrated high side current
monitor produces a current proportional to APD current with better than 10% relative accuracy
over four decades of dynamic range in the APD input current range of 250nA to 2.5mA.
Additionally, the LT3482 is equipped with both a 1.235V internal reference and an auxiliary
reference input (via the CTRL pin), enabling the output voltage to be adjusted while the chip is
operating. Other features include soft-start, internal compensation and thermal shutdown.
The LT3482EUD operates from a 0°C to 85°C temperature range whereas the
LT3482IUD operates from a -40°C to 85°C temperature range. Both parts are available from
90V Boost DC/DC Converter with APD Current Monitor
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stock. Pricing starts at $3.45 each for the LT3482EUD and $4.14 each for the LT3482IUD in
1,000-piece quantities.
Photo Caption: 90V Boost DC/DC Converter with APD Current Monitor
Summary of Features: LT3482
High Output Voltage: Up to 90V
Integrated Schottky Diodes
48V, 280mA Internal Switch
High Side APD Current Monitor
Adjustable Switching Frequency: 650kHz or 1.1MHz
Wide VIN Range: 2.5V to 16V
Low Shutdown Current: <1uA
Internal Compensation
CTRL Pin Allows Output Adjustment with No Polarity Inversion
3mm x 3mm 16-Lead QFN 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 and
are registered trademarks of Linear Technology Corp.
Press Contacts:
John Hamburger, Director Marketing Communications
Tel 408-432-1900 ext 2419
Doug Dickinson, Media Relations Manager
408-432-1900 ext 2233