Datasheet MAX38889 (Maxim) - 4

link to page 10 MAX38889 2.5V to 5.5V, 3A Reversible Buck/Boost Regulator for Backup Applications (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
Circuit of Figure 1, ILX_BU VCAP = 2V, VSYS = RISET = 33kΩ 2.25 3 3.75 LX Peak Backup 2.5V (Note 1) A Current Limit Circuit of Figure 1, ILX_BU VCAP = 2V, VSYS = RISET = 100kΩ 1 2.5V (Note 1) Circuit of Figure 1, RISET = 33kΩ 2.25 3 3.75 LX Peak Charge I VSYS = 3.7V, A Current Limit (Note 1) LX_CHG V RISET = 100kΩ 1 CAP = 2V VFBS = 1.2V, TA = +25°C -0.1 0.01 +0.1 Feedback Input Bias IFBS, IFBCH, V µA Current FBCH = VFBCR = IFBCR 0.5V TA = +125°C 0.01 Enable Input Leakage 0V < V T ENC, A = +25°C -1 0.004 1 I µA Current ENC, IENB VENB < 5.5V TA = +125°C 0.01 LX Low-Side FET R Resistance LOW VLX switched to 0V 42 84 mΩ LX High-Side FET R Resistance HIGH VLX switched to VSYS 57 114 mΩ VENC = VENB = TA = +25°C -1 0.01 1 LX Leakage Current ILX_LKG 0V, VSYS = 5.5V, µA T V A = +125°C 0.26 LX = 0 to 5.5V Typical VCAP = 2V 320 400 480 Maximum On-Time tON Application Circuit, ns V V SYS = 2.9V CAP = 1.2V 570 Minimum Off-Time tOFF Backup mode, VFBS = 1.164V 80 100 120 ns Maximum Duty Cycle DutyMAX VCAP = 0.5V 90 95 % Overtemperature T Lockout Threshold OTLO TJ rising, 15°C typical hysteresis 165 °C VBKB = 5.5V, IBKB_H TA = +25°C -1 0.001 +1 Logic Output Leakage VRDY = 5.5V µA High VBKB = 5.5V, IRDY_H TA = +125°C 0.01 VRDY = 5.5V Logic Output Voltage VBKB_L I Low BKB = 10mA, IRDY = 10mA 0.1 0.4 V VRDY_L High-Side FET Circuit of Figure 1, VSYS = 2.9V, I 60 mA Zero-Crossing ZXP VCAP = 2V (Note 1) Low-Side FET Circuit of Figure 1, VSYS = 3.7V, I 180 mA Zero-Crossing ZXN VCAP = 2V (Note 1)
Note 1:
DC measurement, actual inductor current accuracy in the circuit is affected by the propagation delay time. www.maximintegrated.com Maxim Integrated | 4 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