MIC1344 Smart, 3A, Two-Channel, Power ORing Switch General Description Features The MIC1344 is an advanced two input, one output, hot Two input, one output, power ORing switch swappable, power multiplexer. It has both automatic and Input voltage operating range: 2.8V to 5.5V manual input selection (ENA and ENB) and four status Automatic and manual input selection modes outputs. Four digital and two analog status outputs In automatic mode, the MIC1344 will automatically connect Current blocking: output-to-input and input-to-input the higher of two input voltages (INA or INB), to the output Low on-resistance (70m typical) (OUT). In manual mode, either of the two inputs can be Up to 3A current handling routed to the output, or both power inputs can be turned off so that multiple MIC1344s can be used for more than two Low standby channel current (11A typical) power inputs. Separate current limiting and readback for each channel The MIC1344 has four digital open drain status outputs. Available in 12-pin, 2mm 2mm, QFN (FTQFN) The ASEL and BSEL outputs indicate which input is package selected. The STAOK and STBOK outputs indicate the Thermal-shutdown protection general health of the input channels. Specifically, these 40C to 125C junction temperature range outputs will be inactive (high) if the channel has sufficient input voltage, the channel current is within acceptable Applications limits, the die temperature is not too hot, and the channel Two input to one output power selector has no reverse current detected. Multiple inputs to a single output power selector The current limit for each input channel of the MIC1344 Charger input power selector can be individually set up to 3A, by two external current- limit set resistors (ILIMA and ILMIB). The current flowing in Dual battery selector each of the channels can be read by measuring the Main and backup power selector voltage at these resistors. USB power selector Datasheets and support documentation are available on Portable products Micrels web site at: www.micrel.com. Supercapacitor ORing Backup battery diode ORing Typical Application Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC1344 Ordering Information (1, 2) Part Number Marking Output Current Junction Temperature Range Package MIC1344YFT 4N Adjustable (3.0A maximum) 40C to +125C 12-Pin 2mm 2mm FTQFN Notes: 1. Pin 1 indicator = 2. Green RoHS compliant package. Lead finish is NiPdAu. Mold compound is halogen free. Pin Configuration 12-Pin 2mm 2mm FTQFN (FT) (Top View) Pin Description Pin Number Pin Name Pin Function Supply Voltage Input B. This input may be bypassed to GND with >0.1F, X7R or similar, ceramic 1 INB type capacitor. This input is hot swappable. Open drain output, digital status monitor for supply voltage Input B (INB). Voltage will be low if any of the following conditions occur: INB is below the UVLO limit. The output current from INB is at its set current limit. 2 STBOK The die temperature exceeds the overtemperature limit. Reverse current detected (V > V +100mV). OUT INB Prolonged high hysteresis mode engaged. 3 BSEL Open Drain Output. Low if Input B (INB) is providing power to the OUT pin. A resistor from this pin to ground sets the current limit for INB. The current flowing into INB can be 4 ILIMB monitored by the voltage on this pin. The ENA and ENB digital inputs control which voltage input (INA or INB) is connected to the voltage out (OUT) pin. There is an internal 570k pull-down on this pin to ensure that automatic 5 ENB select mode is active when the logic that is driving the MIC1344 is being powered up. Table 1 shows how to control the power routing with the ENA and ENB inputs. 6 GND Ground. April 24, 2015 Revision 1.0 2