LTC1473L Datasheet | Linear Technology

LTC1473L Dual Low Voltage Power Path TM Switch Driver Features s s s DESCRIPTIO s s s s s Power Path Management for Systems with Multiple DC Sources Switches and Isolates Sources from 3.3V to 10V All N-Channel Switching to Reduce Power Losses and System Cost Built-In Step-Up Regulator for N-Channel Gate Drive Capacitor Inrush and Short-Circuit Current Limited User-Programmable Timer Prevents Overdissipation During Current Limiting Undervoltage Lockout Prevents Operation with Low Inputs Small Footprint: 16-Pin Narrow SSOP The LTC®1473L provides reliable and efficient switching between two DC power sources. This device drives two external sets of back-to-back N-channel MOSFET switches to route power to the input of a low voltage system. An internal boost regulator provides the voltage to fully enhance the logic-level N-channel MOSFET switches while an internal undervoltage lock-out circuit keeps the system alive down to 2.8V. The LTC1473L senses current to limit inrush between the batteries and the system supply capacitor during switchover transitions or during fault conditions. A user-programmable timer monitors the time the MOSFET switches are in current limit and latches them off when the programmed time is exceeded. A unique “2-diode” logic mode ensures system start-up regardless of which input receives power first. , LTC and LT are registered trademarks of Linear Technology Corporation. Power Path is a trademark of Linear Technology Corporation. U APPLICATIO S s s s s s Portable puters Portable Instruments Fault Tolerant puters Battery-Backup Systems 3.3V/5V Power Management TYPICAL APPLICATIO DCIN 3.3V 3.3V to 4-Cell Ni MH Backup Switch Si9926DY BAT54C LOGIC DRIVEN VBAT1 4× Ni MH 1 2 3 4 5 6 LTC1473L IN1 IN2 DIODE TIMER V+ VGG SW GND GA1 SAB1 GB1 16 15 14 RSENSE 0.04Ω 13 SENSE + 12 SENSE - 11 GA2 10 SAB2 9 GB2 CTIMER 2000p F 1m H- 1µF 1µF 7 8 - COILCRAFT 1812LS-105XKBC Si9926DY + COUT 3.3V OR VBAT1 1473 TA01 ABSOLUTE (Note...