Datasheet MAX38889 (Maxim) - 5

MAX38889 2.5V to 5.5V, 3A Reversible Buck/Boost Regulator for Backup Applications
Typical Operating Characteristics
(VSYS = 3.6V, VCAP = 2.7V, CSYS = 150µF, CCAP = 22µF + 10F, L = 0.47µH, unless otherwise noted.)
SYS PIN CHARGING SYS PIN SHUTDOWN CURRENT SYS BACKUP SUPPLY CURRENT SUPPLY CURRENT
toc03 toc01 250 toc02 120 V V V SYS = 3.6V 240 SYS = 3.6V, VFBS = 1.3V FBS = 1.212V 1000 ENC = ENB = 0V VFBCH = VFBCR = 0.485V 110 VFBCH = 0.5V, VFBCR = 0.6V 230 220 100 ) 100 210 90 (nA (µA (µA D G H 200 S U _ C B S _ Y S_ SY 80 I S 190 I SY I S 10 180 70 170 60 160 1 150 50 -40 -20 0 20 40 60 80 100 120 140 -40 -20 0 20 40 60 80 100 120 140 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C)
SWITCHING WAVEFORM SYS READY SUPPLY CURRENT SWITCHING WAVEFORM DURING BACKUP WHILE CHARGING
toc06 10 toc04 toc05 9 VFBS = 1.3V, VFBCH = 0.515V, V 8 FBCR = 0.6V V VSYS 2V/div SYS 2V/div 7 VCAP 1V/div ) 6 VCAP 2V/div (µA Y 5 V 2V/div RD LX _SY 4 V I S LX 5V/div 3 I 2A/div 2 LX 1 ILX 2A/div 0 -40 -20 0 20 40 60 80 100 120 140 VSYS = 3.6V, VCAP = 0V VSYS = 3V, VCAP = 2.7V, ISYS = 1A TEMPERATURE (ºC) 4µs/div 4µs/div
POWER-DOWN EFFICIENCY POWER-UP DURING CHARGING DURING BOOST MODE
toc07 toc08 100 toc09 95 90 V 2V/div SYS VSYS 2V/div 85 ) (% Y 80 2.5V to 5V ENC 1V/div 1V/div NC ENC 75 1.5V to 5V FFICIE 70 E VCAP 1V/div VCAP 2V/div 65 2.5V to 3V 1.5V to 3V 60 ILX 2A/div ILX 2A/div 55 50 VSYS = 3.6V V 1 10 100 1000 SYS = 3.6V, VCAP = 2V 8ms/div 40ms/div I SYS (mA) www.maximintegrated.com Maxim Integrated | 5 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