DATASHEET ISL91128 FN8732 2 Rev.3.00 High Efficiency Buck-Boost Regulator with 4.5A Switches and I C Interface May 3, 2018 The ISL91128 is a high-current, buck-boost switching regulator Features for systems using new battery chemistries. It uses the Renesas Accepts input voltages above or below regulated output proprietary buck-boost algorithm to maintain voltage voltage regulation while providing excellent efficiency and very low output voltage ripple when the input voltage is close to the Automatic and seamless transitions between Buck and output voltage. The device also includes a selectable Bypass Boost modes mode for low power consumption in applications that have a 2 I C interface Sleep or Low Power mode. Input voltage range: 1.8V to 5.5V The ISL91128 is capable of delivering at least 2.2A continuous Continuous output current: up to 2.4A (PVIN = 2.5V, output current (V = 3.3V) across a battery voltage range of OUT V =3.3V) OUT 2.5V to 4.35V. This maximizes the energy utilization of advanced, single-cell Li-ion battery chemistries that have High efficiency: up to 96% significant capacity left at voltages below the system voltage. 30A quiescent current maximizes light-load efficiency Its fully synchronous low ON-resistance 4-switch architecture Selectable bypass power saving mode operation and a low quiescent current of only 30A optimize efficiency under all load conditions. 2.5MHz switching frequency minimizes external component size The ISL91128 supports a broader set of programmable 2 Fully protected for short-circuit, over-temperature, and features that can be accessed using an I C bus interface. With undervoltage a programmable output voltage range of 1.9V to 5.0V, the ISL91128 is ideal for applications requiring dynamically Small 2.15mmx1.74mm WLCSP changing supply voltages. A programmable slew rate can be selected to provide smooth transitions between output voltage Applications settings. Brownout-free system voltage for smart phones and tablet The ISL91128 is available in a 20 bump, 0.4mm pitch WLCSP PCs (2.15mmx1.74mm) with a 2.5MHz switching frequency, which Wireless communication devices further reduces the size of external components. 2G/3G/4G RF power amplifiers Related Literature For a full list of related documents, visit our website ISL91128 product page 100 ISL91128IINZ VIN = 4.2V VIN = 3.3V V 1.8V TO 5.5V IN = LX1 PVIN VIN = 3.6V 95 C L 1 1 10F 1H LX2 90 V = 3.3V VIN OUT VOUT EN C 2 VIN = 2.8V 2x22F FB 85 SDA VIN = 3V SCL 80 75 1 10 100 1000 LOAD CURRENT (mA) FIGURE 1. TYPICAL APPLICATION FIGURE 2. EFFICIENCY: V = 3.3V, T = +25C OUT A FN8732 Rev.3.00 Page 1 of 17 May 3, 2018 SGND PGND EFFICIENCY (%)ISL91128 Block Diagram LX1 LX2 B1 B2 B3 D1 D2 D3 A1 E1 PVIN B2 VOUT E2 A3 E3 SOFT DISCHARGE EN GATE DRIVERS AND ANTI- SHOOT THRU EN EN B4 C1 EN PGND C2 VIN V A4 REF C3 PVIN MONITOR VOUT CLAMP THERMAL SHUTDOWN PWM CONTROL CURRENT SCL C3 DETECT EN SDA C4 VOUT EN MONITOR FB E4 OSC EN REF ERROR AMP VOLTAGE PROG. D4 SGND FIGURE 3. BLOCK DIAGRAM FN8732 Rev.3.00 Page 2 of 17 May 3, 2018 REVERSE CURRENT