Controller tracks and sequences power supply.
October 27, 2003 -
Model LTC2923, in tiny 10-lead MSOP package, controls power-supply start up and shut down by introducing currents into feedback nodes. By properly selecting resistors, supply can be configured to ramp-up and ramp-down together, with options for fixed voltage offsets, time delays, or different ramp rates. Unit allows additional supply to be controlled with FET for systems that require tracking of third supply. It does not affect transient response or stability.
(Archive News Story - Products mentioned in this Archive News Story may or may not be available from the manufacturer.)
Original Press release
Linear Technology Corp.
1630 McCarthy Blvd.
Milpitas, CA, 95035
USA
Tiny Controller Implements Power Supply Tracking & Sequencing
MILPITAS, CA - October 13, 2003 - Linear Technology introduces the LTC2923, a simple and flexible power supply tracking controller in the tiny 10-lead MSOP package for systems with specific supply tracking or sequencing requirements. The LTC2923 controls power supply start up and shut by introducing currents into the feedback nodes, making the relationship between the supplies easily configurable. With just two resistors, a supply is configured to ramp up as a function of a "master" signal. This master signal can be a third supply, a capacitor charging up or a signal generated externally. By properly selecting the resistors, the supplies can be configured to ramp-up and ramp-down together, with options for fixed voltage offsets, time delays, or different ramp rates. The LTC2923 allows an additional supply to be controlled with a series FET for systems that require tracking of a third supply, or when a supply does not allow direct access to its feedback resistors.
The LTC2923 causes the two power supply outputs to track or to follow a sequence without inserting any pass element losses. The LTC2923 does not affect the transient response or stability of the supplies, since the currents are controlled in an open-loop manner. Furthermore, the device presents a high impedance when power-up is complete, effectively removing it from the DC/DC circuit. The LTC2923 is offered in the MSOP-10 package.
Pricing starts at $2.95 each for 1,000 piece quantities.
Summary of Features: LTC2923
Flexible Power Supply Tracking
Tracks Both Up and Down
Power Supply Sequencing
Supply Stability Is Not Affected
Controls Two Supplies without Series FETs
Controls a Third Supply with a Series FET
Electronic Circuit Breaker
Available in 10-Pin MSOP Package
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
READER SERVICE: Call toll-free 1-800-4-LINEAR (for literature only), or go to the company's web site: http://www.linear.com
Note: LT, AND LTC are registered trademarks of Linear Technology Corp
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