LTC4419CDD Datasheet, PDF (1/20 Pages) Linear Integrated Systems – 18V Dual Input Micropower PowerPath Prioritizer

LTC4419
18V Dual Input Micropower
PowerPath Prioritizer
Features
Description
nn _{Selects Highest Priority Valid Supply from Two Inputs}
nn _{Wide 1.8V to 18V Operating Range}
nn _{Internal Dual 2Ω, 0.5A Switches}
nn _{Low 3.6µA Operating Current}
nn _{Low 320nA V2 Current When V1 Connected to OUT}
nn _{Blocks Reverse and Cross Conduction Currents}
nn _{Reverse Supply Protection to –15V}
nn _{V2 Freshness Seal/Ship Mode}
nn _{±1.5% Accurate Adjustable Switchover Threshold}
nn _{Two Auxiliary ±2.3% Accurate Voltage Comparators}
nn _{Overcurrent and Thermal Protection}
nn _{Thermally Enhanced 10-Pin 3mm × 3mm DFN}
and 12-Lead Exposed Pad MSOP Packages
Applications
nn _{Low Power Battery Backup}
nn _{Portable Equipment}
nn _{Point-of-Sale (POS) Equipment}
The LTC^®4419 is a dual input monolithic PowerPath™
prioritizer with low operating current, that provides backup
switchover for keeping critical circuitry alive during brown
out and power loss conditions. Unlike diode-OR products,
little current is drawn from the inactive supply even if its
voltage is greater than the active supply.
Internal 2Ω, current limited PMOS switches provide power
path selection from a primary input (V1) or a backup input
(V2) to the output. An adjustable voltage monitor set via
an external resistive divider provides flexibility in setting
the V1 to V2 switchover threshold. When primary input V1
drops, the ADJ monitor input causes OUT to be switched
to V2. Fast non-overlap switchover circuitry prevents both
reverse and cross conduction while minimizing output
droop.
The LTC4419 has two auxiliary comparators with open-
drain outputs that provide flexible voltage monitoring. The
V2ON output indicates if V2 is powering OUT. Freshness
seal mode prevents V2 battery discharge during storage
or shipment.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Typical Application
5V
WALL
ADAPTER
V1
OUT
C1
10µF
1M
ADJ CMPOUT1
237k
CMP1 CMPOUT2
121k
LTC4419
OUT
1M 1M
V1UV
V2UV
+
7.4V
Li-Ion
V2
4.02M
V2ON
CMP2
280k
GND
4419 TA01a
V2ON
SWITCHOVER
THRESHOLD: V1 < 4V (V1 FALLING)
V1UV THRESHOLD: V1 < 4.4V (V1 FALLING)
V2UV THRESHOLD: V2 < 6V (V2 FALLING)
Typical Switchover Waveforms
V2
2V/DIV
V1
2V/DIV
OUT
C_OUT = 10µF
I_LOAD = 100mA
SWITCHOVER
THRESHOLD
50µs/DIV
4419 TA01b
4419f
For more information www.linear.com/LTC4419
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