Milpitas, Calif. Linear Technology Corp. has introduced a 1.2-A, 1.5-MHz monolithic current-mode, step-down switching regulator with a programmable output current limit for battery charger applications. Typically, the LT3653 is used with battery charger power path controllers to pre-regulate the output and optimize battery charger efficiency.
The wide operating input voltage of 7.5 V to 30 V makes the LT3653 well-suited for a variety of input sources including unregulated 12-V wall adapters, 24-V industrial supplies and Firewire as well as automotive applications. Onboard input over-voltage lockout protects the device through input transients as high as 60 V such as those commonly found in automotive applications.
The LT3653's control pin is available for external battery tracking, known as Bat-Track control. This function keeps the output voltage only 300 mV above the Li-ion battery voltage, which minimizes thermal issues while simultaneously optimizing charger efficiency. The LT3653 also offers an adjustable output current limit which can be set between 400 mA and 1.2 A via an external resistor. The LT3653 does not allow reverse discharge from the battery to VIN, eliminating the need for a blocking FET. It also uses a 1.5-MHz oscillator, internal compensation and an internal boost diode to minimize the overall solution footprint. Combined with a 2 x 3-mm DFN package, the LT3653 offers a very compact high-voltage input regulator for battery charger applications, Linear Tech said.
Pricing: Starts at $2.50 each for the LT3653EDCB and $2.88 for the industrial-grade LT3653IDCB (-40°C to 125°C operating junction temperature), both in quantities of 1,000.
Availability: Both versions are available from stock.
Product information: LT3653
Linear Technology Inc. , www.linear.com