Datasheet ISL9122A Ultra-Low IQ Buck-Boost Regulator With Bypass The ISL9122A is a highly integrated non-inverting Features buck-boost switching regulator that accepts input • 1300nA quiescent current voltages both above or below the regulated output voltage. It features an extremely low quiescent current • 84% efficiency at 10µA load consumption of 1300nA in Regulation mode, 120nA in • 97% peak efficiency Forced Bypass mode, and 8nA in Shutdown mode. It provides 84% efficiency at 10µA load (V • Input voltage range: 1.8V to 5.5V IN = 3.6V, VOUT = 3.3V) and has a peak efficiency greater than • Output voltage range: 1.8V to 5.375V 97%. It supports input voltages from 1.8V to 5.5V. • Output current: up to 500mA (VIN = 3.6V, The ISL9122A has automatic bypass functionality for VOUT = 3.3V) situations in which the input voltage is close to the • Selectable Forced and Auto Bypass power saving output voltage, and it automatically transitions modes between Buck and Boost modes without significant output disturbance. In addition to the automatic • Seamless PWM/PFM and buck/boost transition bypass functionality, the Forced Bypass power-saving • I2C Control and voltage adjustability mode can be chosen if voltage regulation is not • Hysteretic controller required. Forced Bypass power saving mode is accessible using the I2C interface bus. • Small 1.8mmx1.0mm WLCSP and 3.0mm x 2.0mm 8 Ld DFN packages The ISL9122A is capable of delivering up to 500mA of output current (VIN = 3.6V, VOUT = 3.3V) and provides Applications excellent efficiency because of its adaptive frequency hysteretic control architecture. • Smart watches and wristband devices The ISL9122A is designed for stand-alone • Wireless earphones applications and supports a default output voltage at • Internet of Things (IoT) devices Power-On Reset (POR). After POR, the output • Water, gas, and oil meters voltage can be adjusted in the range of 1.8V to 5.375V by using the I2C interface bus. Specific default • Portable medical devices output voltages are available upon request. • Hearing aid devices The ISL9122A requires only a single EIA 0603 size inductor and two external capacitors. Power supply Related Literature solution size is minimized by a 1.8mmx1.0mm For a full list of related documents, visit our website: WLCSP and is also available in a 3.0mmx2.0mm • ISL9122A product page 8 Ld plastic DFN. 100L11µH/060395VLX1LX2IN = 1.8V to 5.5VVOUT = 1.8V to 5.375V)90VINVOUTC2(%C110µF/060310µF/060385ISL9122ASDAEfficiency80I2C HostEnableSCLENDisableVIN = 1.8VVIN = 4.5V75VIN = 2.5VVIN = 5.0VGNDVIN = 3.6VVIN = 5.5V700.010.11101001000Load Current (mA)Figure 1. Typical ApplicationFigure 2. Efficiency: VOUT = 3.3V, TA = +25°C FN8947 Rev.1.00 Page 1 of 20 Sep.14.20 Document Outline Features Applications Related Literature Contents 1. Overview 1.1 Block Diagram 1.2 Ordering Information 1.3 Pin Configurations 1.4 Pin Descriptions 2. Specifications 2.1 Absolute Maximum Ratings 2.2 Thermal Information 2.3 Recommended Operation Conditions 2.4 Analog Specifications 2.5 I2C Interface Timing Specifications 3. Typical Performance Curves 4. Functional Description 4.1 Enable Input 4.2 Soft Discharge 4.3 Start-Up 4.4 Overcurrent/Short-Circuit Protection 4.5 Thermal Shutdown 4.6 Buck-Boost Conversion Topology 4.7 PWM Operation 4.8 PFM Operation 4.9 Operation With VIN Close to VOUT 4.10 Forced Operating Modes 4.11 I2C Serial Interface 4.12 Protocol Conventions 4.13 Write Operation 4.14 Read Operation 4.15 Register Descriptions 4.15.1 RO_REG1 4.15.2 INTFLG_REG 4.15.3 VSET 4.15.4 CONV_CFG 4.15.5 INTFLG_MASK 5. Revision History 6. Package Outline Drawings