Renesas announces buck-boost DC/DC converter with ultra-low quiescent current

Target applications include wireless earbuds, fitness bands, smart watches, water and gas metres, 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 optimise system power consumption. The regulator’s power boost up to 5.375V maximises RF capabilities of IoT devices across their battery range. Its PFM and PWM functionality maximises efficiency over the whole output current range. In forced PWM mode, the regulator always switches at 2.5MHz frequency, which improves EMI performance of the system.

“With the explosive growth of IoT wireless connectivity applications, the ISL9122A buck-boost regulator’s fast transitions from no load to full load is ideal for powering the newest generation of devices,” said Andrew Cowell, Vice President, Mobility, Infrastructure and IoT Power Business Division at Renesas. “Our customers praise the ISL9122A’s flexibility, dynamic voltage scaling and lowest regulated standby power consumption.”

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

• Ultra-low IQ <1.3µA and low shutdown mode current of 7nA to extend battery life
• High efficiency at light load (84% @ 10µA) 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 1.8-5.5V, 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

Pricing and availability

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.