DATASHEET ISL9120 FN8659 Rev.3.00 Compact High Efficiency Low Power Buck-Boost Regulator Nov 29, 2018 The ISL9120 is a highly integrated buck-boost switching Features regulator that accepts input voltages either above or below the Accepts input voltages above or below regulated output regulated output voltage. This regulator automatically voltage transitions between buck and boost modes without significant output disturbance. The ISL9120 also has automatic bypass Automatic bypass mode functionality functionality. When the input voltage is generally within 1% to Automatic and seamless transitions between buck and 2% of the output voltage, there will be a direct bypass boost modes connection between the VIN and VOUT pins. In addition to the Input voltage range: 1.8V to 5.5V automatic bypass functionality, the ISL9120 also has forced bypass functionality with the use of the BYP pin. Selectable forced bypass power saving mode This device is capable of delivering up to 800mA of output Adaptive multilevel current limit scheme to optimize current (V = 2.5V, V = 3.3V) and provides excellent efficiency at low and high currents IN OUT efficiency due to its adaptive current limit Pulse Frequency Output current: up to 800mA (V = 2.5V, V = 3.3V) IN OUT Modulation (PFM) control architecture. High efficiency: up to 98% The ISL9120 is designed for stand-alone applications and 41A quiescent current maximizes light-load efficiency supports a 3.3V fixed output voltage or variable output voltages with an external resistor divider. The forced bypass Fully protected for over-temperature and undervoltage power saving mode can be chosen if voltage regulation is not Small 1.41m x1.41mm WLCSP required. The device consumes less than 3.5A of current over the operating temperature range in forced bypass mode. Applications The ISL9120 requires only a single inductor and very few Smartphones and tablets external components. Power supply solution size is minimized by a 1.41mmx1.41mm WLCSP. Portable consumer and wearable devices Related Literature For a full list of related documents, visit our website: - ISL9120 device page 100 V = V = 3.6V IN IN ISL9120IINZ 1.8V TO 5.5V 95 VIN LX1 C 1 L 1 90 10F 1 H LX2 V = 3.4V V = 4V IN IN 85 V = 3V ENABLE VOUT V = 3.3V IN EN OUT DISABLE V = 2.5V IN 80 C 2 FB FORCED BYPASS BYP 22F TO 47F BUCK-BOOST 75 GND PGND 70 1 10 100 1000 OUTPUT CURRENT (mA) FIGURE 1. TYPICAL FIXED OUTPUT APPLICATION FIGURE 2. EFFICIENCY: V = 3.3V, T = +25C OUT A FN8659 Rev.3.00 Page 1 of 14 Nov 29, 2018 EFFICIENCY (%)- ISL9120 Block Diagram LX1 LX2 A1 C1 VIN A2 C2 VOUT SOFT V REF DISCHARGE GATE DRIVERS AT ANTI- + EN SHOOT THRU EN B1 PGND PVIN MONITOR VOUT CLAMP THERMAL SHUTDOWN PFM CONTROL CURRENT DETECT EN B2 BYPS A3 VOLTAGE COMPARATOR C3 FB - + EN VREF + ILIM - VOLTAGE PROG. CURRENT COMPARATOR B3 GND FIGURE 3. BLOCK DIAGRAM Pin Configuration Pin Descriptions ISL9120 PIN PIN NAMES DESCRIPTION 9 BUMP WLCSP C1 LX2 Inductor connection, output side. BOTTOM VIEW C2 VOUT Buck-boost output. Connect a 22F or 47F LX2 VOUT FB capacitor to PGND. C C3 FB Voltage feedback pin, connect directly to VOUT pin for fixed output version. PGND EN GND B1 PGND Power ground for high switching current. B B2 EN Logic input, drive HIGH to enable device. Do LX1 VIN BYP not leave floating. A B3 GND Analog ground pin. 123 A1 LX1 Inductor connection, input side. A2 VIN Power supply input. Range: 1.8V to 5.5V. Connect a 10F capacitor to PGND. A3 BYP Forced bypass mode enable pin. Logic high for forced bypass mode operation. Logic low for buck-boost mode operation. Do not leave floating. FN8659 Rev.3.00 Page 2 of 14 Nov 29, 2018 REVERSE CURRENT