Datasheet LTC4362-1, LTC4362-2 (Analog Devices) - 6

LTC4362-1/LTC4362-2
BLOCK DIAGRAM
SENSE SENSE RESISTOR IN 31mΩ OUT 5.8V GATEP 200k CHARGE PUMP 10µA 1.8M 5.8V ON GATE HIGH 500k + COMPARATOR + 1V – GATE HIGH – THRESHOLD PWRGD 5µA CONTROL OVERCURRENT COMPARATOR + – +– 47mV OVERVOLTAGE COMPARATOR + 5.8V – 5.7V GND 436212 BD
OPERATION
Mobile devices like cell phones and MP3/MP4 players ports. A user might unknowingly plug in the wrong adap- have highly integrated subsystems fabricated from deep tor, damaging the device with a high or even a negative submicron CMOS processes. The small form factor is power supply voltage. accompanied by low absolute maximum voltage ratings. The LTC4362 protects low voltage electronics from The sensitive electronics are susceptible to damage from these overvoltage conditions by controlling an internal transient or DC overvoltage conditions from the power N-channel MOSFET configured as a pass transistor. At supply. power-up (VIN > 2.1V), a start-up delay cycle begins. Any Failures or faults in the power adaptor can cause an over- overvoltage condition causes the delay cycle to continue voltage event. So can hot-plugging an AC adaptor into the until a safe voltage is present. When the delay cycle com- power input of the mobile device (see Application Note pletes, an internal high-side switch driver slowly ramps up 88). Today’s mobile devices derive their power supply or the MOSFET gate, powering up the output at a controlled recharge their internal batteries from multiple alternative rate and limiting the inrush current to the output capacitor. inputs like AC wall adaptors, car battery adaptors and USB Rev. B 6 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings order information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts