DC1863A

DEMO MANUAL DC1863A LTC3621 17V, 1A Monolithic Synchronous Step-Down Regulator DESCRIPTION Demonstration circuit 1863 is a step-down converter, capable of delivering up to 1A of output current from a minimum input voltage of 2.7V. The DC1863A uses the power-saving LTC®3621 1MHz monolithic synchronous buck regulator in a small 8-lead MS8 package. The LTC3621 IC quiescent currents can be as low as 3.5μA in normal operation, and less than 0.1μA in shut down. The output voltage range of the DC1863A is from as low as 0.6V, the reference voltage of the LTC3621, to as high as the maximum input voltage, 17V. The DC1863A can operate in three distinct operating modes: Burst Mode® PERFORMANCE SUMMARY PARAMETER operation for highest efficiency at low output currents, forced continuous mode for lowest output ripple voltage, and pulse-skipping mode for the best compromise operation between the two other modes, by setting the mode pin to INTVCC (3.6V), INTVCC/2, or ground respectively. All these features make the DC1863A an ideal circuit for use in any high efficient, low power application. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C CONDITIONS VALUE Input Voltage Range 2.7V to 17V Output Voltage Range 0.6V to VIN Run/Shutdown Output Voltage Regulation Typical Output Ripple Voltage RUN Pin = GND Shutdown RUN Pin = VIN Operating VIN = 2.7V to 17V, IOUT = 0A to 1A 1.2V ±3% Typ (1.164V to 1.236V) VIN = 2.7V to 17V, IOUT = 0A to 1A 1.8V ±3% Typ (1.746V to 1.854V) VIN = 2.7V to 17V, IOUT = 0A to 1A 2.5V ±3% Typ (2.425V to 2.575V) VIN = 3.5V to 17V, IOUT = 0A to 1A 3.3V ±3% Typ (3.201V to 3.399V) VIN = 5.2V to 17V, IOUT = 0A to 1A 5V ±3% Typ (4.85V to 5.15V) VIN = 12V, VOUT = 5V, IOUT = 1A (20MHz BW)