LTC4412HV_15 Datasheet, PDF (1/12 Pages) Linear Technology – 36V, Low Loss PowerPath Controller in ThinSOT

FEATURES
s _{Very Low Loss Replacement for Power Supply}
OR’ing Diodes
s _{3V to 36V AC/DC Adapter Voltage Range}
s _{–40°C to 125°C Operating Temperature Range}
s _{Minimal External Components}
s _{Automatic Switching Between DC Sources}
s _{Simplifies Load Sharing with Multiple Batteries}
s _{Low Quiescent Current: 11µA}
s _{2.5V to 36V Battery Voltage Range}
s _{Reverse Battery Protection}
s _{Drives Almost Any Size MOSFET for Wide Range of}
Current Requirements
s _{MOSFET Gate Protection Clamp}
s _{Manual Control Input}
s _{Low Profile (1mm) SOT-23 (ThinSOT}^TM_{) Package}
U
APPLICATIO S
s _{Industrial and Automotive Applications}
s _{Notebook and Handheld Computers}
s _{USB-Powered Peripherals}
s _{Uninterruptable Power Supplies}
s _{Logic Controlled Power Switch}
, LTC and LT are registered trademarks of Linear Technology Corporation.
PowerPath and ThinSOT are trademarks of Linear Technology Corporation.
LTC4412HV
36V, Low Loss PowerPath^TM
Controller in ThinSOT
DESCRIPTIO
The LTC^®4412HV controls an external P-channel MOSFET
to create a near ideal diode function for power switchover
or load sharing. This permits highly efficient OR’ing of mul-
tiple power sources for extended battery life and low self-
heating. When conducting, the voltage drop across the
MOSFET is typically 20mV. For applications with a wall
adapter or other auxiliary power source, the load is auto-
matically disconnected from the battery when the auxiliary
source is connected. Two or more LTC4412HVs may be in-
terconnected to allow load sharing between multiple bat-
teries or charging of multiple batteries from a single charger.
The LTC4412HV is an extended supply and temperature
range version of the LTC4412.
The wide supply operating range supports operation from
one to eight Li-Ion cells in series. The low quiescent
current (11µA typical) is independent of the load current.
The gate driver includes an internal voltage clamp for
MOSFET protection.
The STAT pin can be used to enable an auxiliary P-channel
MOSFET power switch when an auxiliary supply is
detected. This pin may also be used to indicate to a micro-
controller that an auxiliary supply is connected. The con-
trol (CTL) input enables the user to force the primary
MOSFET off and the STAT pin low.
The LTC4412HV is available in a low profile (1mm) SOT-23
package.
TYPICAL APPLICATIO
WALL
ADAPTER
INPUT
BATTERY
CELL(S)
1N5819
FDN306P
1 ^LTC4412HV 6
V_IN SENSE
2
5
GND GATE
3
4
CTL STAT
C_OUT
V_CC
TO LOAD
470k _{STATUS OUTPUT}
LOW WHEN WALL
4412HV F01 _{ADAPTER PRESENT}
LTC4412HV vs Schottky Diode Forward Voltage Drop
1
CONSTANT
R_ON
LTC4412HV
CONSTANT
VOLTAGE
SCHOTTKY
DIODE
Figure 1. Automatic Switchover of Load Between a Battery and a Wall Adapter
0
0.02
FORWARD VOLTAGE (V)
0.5
4412HV F01b
sn4412hv 4412hvfs
1