STEVAL-ISA078V1 STMicroelectronics

STEVAL-ISA078V1 High efficiency synchronous step-up regulator based on the L6926 Data brief 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 600 MHz switching frequency externally synchronizable up to 1.4 MHz Short-circuit protection The low MOSFET R ensures high efficiency DS(on) RoHS compliant at high output current. Additional beneficial features are: hysteretic Description UVLO, OVP, constant current short-circuit protection, Power Good and thermal shutdown. The STEVAL-ISA078V1 demonstration board is a high efficiency monolithic synchronous step-down The MSOP8 package allows significant space regulator capable of delivering up to 800 mA of savings on the board. continuous output current and of regulating the output voltage from 0.6 V up to V thanks to the IN 100% duty cycle operation capability. The input voltage ranges from 2 V to 5.5 V. The control loop architecture is based on a constant frequency peak current mode, while high efficiency at light loads is achieved by a low consumption functionality. The very low quiescent current (25 A) and shutdown current (0.2 A) means that the device is very suitable for supplying battery-powered equipment like PDAs, hand-held terminals, DSCs (digital still cameras) and cellular phones. The switching frequency is internally set at 600 kHz, but the device can be externally synchronized up to 1.4 MHz. An internal reference voltage of 0.6 V (typ.) allows the device to regulate a minimum output voltage of the same low value. March 2012 Doc ID 022889 Rev 1 1/4 For further information contact your local STMicroelectronics sales office. www.st.com 4Circuit schematic STEVAL-ISA078V1 1 Circuit schematic Figure 1. Circuit schematic L1 6.8H V = 1.8V IN LX 5 V = 2 to 5.5V V IN CC 6 R4 C2 RUN 100k L6926 22F 1 PGOOD R3 C1 8 6.3V SYNC 200k 10F 7 3 6.3V VFB R2 24 100k COMP GND C3 220pF R1 10k AM12057v1 2/4 Doc ID 022889 Rev 1