Micropower Pushbutton On/Off Controller Provides Automatic Turn-On/Off Capabilities
Linear Technology Corporation has introduced the LTC2955 pushbutton on/off controller that manages 1.5V to 36V system power via a pushbutton interface or the presence of a supply. Unlike typical pushbutton controllers that initiate system power-ups only with the toggle of a pushbutton, the LTC2955 automatically turns on a system when power is applied from a primary or secondary supply, such as a wall adapter or car battery. When powered up, the LTC2955 can power down a system via pushbutton and optionally can use interrupt logic to request a system power-down in menu-driven applications (“soft” shutdown), or automatically power-down a system if the supply is removed. Absolutely no code is required to configure the device. The LTC2955 is a simple, yet configurable, high voltage pushbutton controller that provides a common set of on/off power options.
The LTC2955’s wide operating range of 1.5V to 36V caters to single cell, multicell and high voltage applications, including desktop and notebook computers, consumer electronics, portable instruments and automotive electronics. The robust pushbutton input handles wide voltage swings of up to ±36V and ESD strikes up to ±25kV, and is designed to operate in noisy environments. A mode select pin enables users to select automatic turn-on and turn-off combinations, and battery run time is maximized thanks to a low 1.2µA quiescent current. The LTC2955’s power good output, interrupt output, and kill input provide simple interfacing with an optional microprocessor. In case a microprocessor fails to respond to an interrupt request, an adjustable turn-off timer enables users to set the required amount of time a pushbutton must be depressed in order to force a system power-down.
The LTC2955 is available today in both positive (LTC2955-1) and negative (LTC2955-2) enable polarities, and in a 10-pin 3mm x 2mm DFN or 8-lead ThinSOT™ package. Offered over the commercial and industrial temperature ranges, pricing for the LTC2955 starts at $1.98 each in 1000-piece quantities.
For more information, please visit www.linear.com/pushbutton.
Posted by Ron M. Seidel, Editorial Intern
March 7, 2012