DATASHEET ISL9120IR FN8743 Rev 1.00 Compact High Efficiency Low Power Buck-Boost Regulator February 2, 2016 The ISL9120IR 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 ISL9120IR also has automatic bypass Automatic bypass mode functionality functionality for when the input voltage is generally within 1% Automatic and seamless transitions between buck and to 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 ISL9120IR also has a forced bypass functionality with the use of the BYPS 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 ISL9120IR 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 3mmx3mm 12 Ld TQFN package required. The device consumes less than 3.5A of current over the operating temperature range in the forced bypass mode. Applications The ISL9120IR requires only a single inductor and very few Smartphones and tablets external components. Power supply solution size is minimized by a 3mmx3mm 12 Ld TQFN package. Portable consumer and wearable devices 100 V = IN 1.8V TO 5.5V ISL9120IRNZ V = 3.6V IN 95 VIN LX1 C 1 L 1 10F 90 1H LX2 V = 4V IN ENABLE V = 2.5V VOUT IN 85 EN V = 3.3V OUT DISABLE V = 3.4V IN V = 3V IN C 2 BYPASS FB 80 BYPS 22F or 47F BUCK-BOOST 75 70 1 10 100 1000 OUTPUT CURRENT (mA) FIGURE 1. TYPICAL FIXED OUTPUT APPLICATION FIGURE 2. EFFICIENCY: V = 3.3V, T = +25C OUT A FN8743 Rev 1.00 Page 1 of 13 February 2, 2016 GND PGND EFFICIENCY (%)- ISL9120IR 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 ISL9120IR PIN NUMBER PIN NAME DESCRIPTION (12 LD 3x3 TQFN) TOP VIEW 1, 12 LX2 Inductor connection, output side. 2 PGND Power ground for high switching current. 3, 4 LX1 Inductor connection, input side. LX2 EN 1 9 5, 6 VIN Power supply input. Range: 1.8V to 5.5V. Connect 1x 10F capacitor to PGND. EPAD PGND GND 2 8 7 BYPS Bypass mode enable pin. HIGH for bypass LX1 BYPS 3 7 mode. LOW for buck-boost mode. 8GND Analog ground pin. 9 EN Logic input, drive HIGH to enable device. 10 FB Voltage feedback pin. 11 VOUT Buck-boost output. Connect 22F or 47F capacitor to PGND. FN8743 Rev 1.00 Page 2 of 13 February 2, 2016 LX1 4 12 LX2 VIN 5 11 VOUT VIN 6 10 FB REVERSE CURRENT