Datasheet MAX38889 (Maxim) - 3

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MAX38889 2.5V to 5.5V, 3A Reversible Buck/Boost Regulator for Backup Applications
Electrical Characteristics
(VSYS = 3.7V, VCAP = 2.8V, TJ = -40C to +125C (typical values at TJ = +25C), circuit of Figure 1, unless otherwise specified.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Guaranteed by LX peak backup current SYS Voltage Range VSYS 2.5 5.5 V and SYS shutdown current Guaranteed by maximum on-time and CAP Voltage Range VCAP 0.5 5.5 V CAP shutdown current SYS Shutdown V T SYS = 5.5V, A = +25°C 0.010 1 I µA Current SYS_SD VENC = VENB = 0V TA = +125°C 0.46 VFBS = 1.3V, TA = +25°C 4.5 8 SYS Ready Supply I V µA Current SYS_RDY FBCH = 0.515V, T V A = +125°C 8 FBCR = 0.6V SYS Backup Supply VFBS = 1.212V, VFBCH = 0.5V, I 75 150 µA Current SYS_BU VFBCR = 0.6V CAP Shutdown V T CAP = 5.5V, A = +25°C 0.01 1 I µA Current CAP_SD VENC = VENB = 0V TA = +125°C 0.2 System Undervoltage VSYS falling, 100mV typical hysteresis, V 2.1 2.2 2.3 V Threshold UVLOF VCAP = 0V FBS Backup Voltage VFBS_BU VFBS rising, when discharging stops 1.188 1.2 1.212 V FBS Charging From VFBS backup voltage, when V 2 2.5 3 % Threshold FBS_CHG charging begins V FBCH Threshold FBCH rising, when charging stops; VTH_FBCH 0.495 0.5 0.505 V 10mV typical hysteresis V FBCR Threshold FBCR rising, when RDY releases; VTH_FBCR 0.495 0.5 0.505 V 10mV typical hysteresis VFBS = 1.3V, VIL VFBCH = 0.4V, VENC rising 600 850 when LX switching ENC Input Threshold mV VFBS = 1.3V, VIH VFBCH = 0.4V, VENC falling 950 1200 when LX switching VFBS = 1.1V, VIL VFBCH = 0.4V, VENB rising 600 850 when LX switching ENB Input Threshold mV VFBS = 1.1V, VIH VFBCH = 0.4V, VENB falling 950 1200 when LX switching ISET Resistor Range RISET Guaranteed by LX peak current limits 33 100 kΩ LX Switching F Frequency SW VCAP = 1.5V, ISYS = 1A 1.2 MHz www.maximintegrated.com Maxim Integrated | 3 Document Outline Product Highlights Key Applications Simplified Application Diagram Pin Configuration Absolute Maximum Ratings Package Information Electrical Characteristics Typical Operating Characteristics Pin Configuration Pin Descriptions Functional Diagram Detailed Description Application Circuits Supercapacitor Voltage Configuration System Voltage Configuration Charge/Discharge Current Configuration Charging Backup Applications Information Capacitor Selection Supercapacitor Selection Inductor Selection Status Flags BKB Flag RDY Flag Enabling the Device Charger Enable Input (ENC) Backup Enable Input (ENB) PCB Layout Guidelines Ordering Information