ISL9123 Ultra-Low IQ Buck Regulator with Bypass Renesas Electronics ISL9123 Ultra-Low IQ Buck Regulator with Bypass integrates a complete buck switching regulator, with a PWM controller, internal switches, references, protection circuitry, and control inputs, in a compact Wafer Level Chip Scale Package (WLCSP). The ISL9123 Buck Regulator is capable of supplying output voltage down to 0.4V. It features an extremely low quiescent current consumption of 950nA in Regulation mode, 140nA in Forced Bypass mode, and 7nA in Shutdown mode. It provides 80% efficiency at 10µA load and has a peak efficiency of 97%. The Renesas Electronics ISL9123 supports input voltages from 1.8V to 5.5V.