STEVAL-ISA079V1 STMicroelectronics

STEVAL-ISA079V1 High efficiency monolithic synchronous step-down regulator based on the L6928D Data brief preliminary data Features 2 V to 5.5 V battery input range High efficiency: up to 95% Extremely low quiescent current 1 A max. shutdown supply current 800 mA max. output current Adjustable output voltage from 0.6 V Low dropout operation: up to 100% duty cycle 1% output voltage accuracy 1.4 MHz switching frequency externally synchronizable from 1 MHz to 2 MHz Short-circuit protection RoHS compliant Description The STEVAL-ISA079V1 demonstration board is based on the DC-DC monolithic regulator L6928D, specifically designed to provide extremely high efficiency. The L6928D supply voltage can be as low as 2 V, allowing it to be used in single Li-Ion cell supplied applications. Output voltage can be selected by an external divider down to 0.6 V. Duty cycle can saturate to 100%, allowing low dropout operation. The previous part number for this demonstration board was EVAL6928D. March 2012 Doc ID 022890 Rev 1 1/4 This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to www.st.com 4 change without notice. For further information contact your local STMicroelectronics sales office.Circuit schematic STEVAL-ISA079V1 1 Circuit schematic Figure 1. Circuit schematic L1 4.7H V = 1.8V IN LX 5 V = 2 to 5.5V V IN CC 6 R4 C2 RUN 100k L6928D PGOOD 10F 1 R3 C1 8 6.3V SYNC 200k 10F 7 3 6.3V VFB R2 24 100k COMP GND C3 220pF R1 10k AM12058v1 2/4 Doc ID 022890 Rev 1