Date: 24/09/2009

High compact synchronous step-down regulator for dual output voltage rails

Linear has introduced the LTC3619, a dual output, 2.25 MHz synchronous buck regulator with programmable average input current limit that delivers up to 800mA of continuous output current from one channel and 400mA from the other with high efficiencies of 96%. The LTC3619 with a constant frequency and current mode architecture suitable for single-cell Li-Ion and USB applications.

The LTC3619's operating input voltage range from 2.5V to 5.5V, and generates two independent output voltages as low as 0.6V, enabling it to power the low voltage DSPs and microcontrollers. The LTC3619 uses a switching frequency of 2.25 MHz, which allows for the utilization of tiny ceramic capacitors and inductors less than 1 mm in height.

The other key features are,

Programmable average input current limit of ±5% Accuracy
Low ripple (<25mVP-P) burst mode operation of IQ = 50µA
Power output voltage monitor for each channel
Low dropout operation: 100% duty cycle
Internal Soft-Start for each channel
Current mode operation for better line and load transient response
±2% output voltage accuracy
Short-circuit protected
Shutdown current = 1µA

Package:
LTC3619EDD and LTC3619BEDD: 3mm x 3mm DFN-10 package
LTC3619EMSE and LTC3619BEMSE: Thermally enhanced MSOP-10 package
LTC3619IDD and LTC3619BIDD: DFN-10 package
LTC3619IMSE and LTC3619BIMSE: MSOP-10E package

Price:

LTC3619EDD, LTC3619BEDD, LTC3619EMSE and LTC3619BEMSE:
Starts at $2.25 each for 1k pieces

LTC3619IDD, LTC3619BIDD, LTC3619IMSE and LTC3619BIMSE:
Each $2.65 for 1K pieces

For more details visit www.linear.com