Renesas Electronics Corporation introduced the ISL9122A, a flexible buck-boost switching regulator with bypass mode that provides ultra-low quiescent current (IQ) for powering sensors, microcontrollers (MCUs), wireless devices, and other system components. Operating with battery output from 1.8V to 5.5V, the ISL9122A extends the battery life of smart IoT devices powered by coin-cell, lithium, and multiple series alkaline batteries. Target applications include wireless earbuds, fitness bands, smartwatches, water and gas meters, portable medical devices, and a wide range of battery-operated smart IoT devices.

The ISL9122A buck-boost switching regulator implements dynamic voltage scaling (DVS) in I2C programmable 25mV steps to optimize system power consumption. The regulator’s power boost up to 5.375V maximizes RF capabilities of IoT devices across their battery range. Its PFM and PWM functionality maximizes efficiency over the whole output current range. In forced PWM mode, the regulator always switches at 2.5MHz frequency, which improves the EMI performance of the system.

The ISL9122A buck-boost regulator joins the recently released ISL9123 buck regulator. Both ultra-low IQ switching regulators can power the Renesas RL78 Family of 8/16-bit ultra-low energy MCUs, RA Family of 32-bit MCUs with Arm Cortex-M Core, and the RE Family of embedded controllers for wearables and energy harvesting applications.

Key Features of ISL9122A Buck-Boost Regulator with Bypass include Ultra-low IQ <1.3 µA and low shutdown mode current of 7 nA to extend battery life; High efficiency at light load (84% @ 10 µA) and 97% peak efficiency to reduce power drain and heat buildup; Automatic and selectable forced bypass power-saving mode reduces IQ; Wide input voltage range from 1.8V to 5.5V, works with multiple battery topologies; Large adjustable output voltage range from 1.8V to 5.375V in 25mV increments; Max output current up to 500mA (Vout = 3.3V, Vin = 3.6V); Ultra-small footprint with 1.8 x 1.0mm WLCSP package or 3x2mm DFN package saves board space; Only requires three external components: one inductor, and input and output capacitors; Full protection against overcurrent, short-circuit and overheating

The ISL9122A is available now from Renesas’ worldwide distributors and is priced at $0.89 USD (8-lead DFN package) and $0.78 USD (8-bump WLCSP package) each in 1,000-unit quantities.

Two ISL9122A evaluation boards that allow designers to evaluate device features and performance are also available: The ISL9122AIRN-EVZ with 3.3V default output (DFN) and ISL9122AIIN-EVZ with 3.3V default output (WLCSP), both priced at $70 USD.