TPS2043 Datasheet, PDF (23/25 Pages) Texas Instruments – TRIPLE POWER-DISTRIBUTION SWITCHES

TPS2043, TPS2053
TRIPLE POWER-DISTRIBUTION SWITCHES
APPLICATION INFORMATION
SLVS191 – JANUARY 1999
generic hot-plug applications (see Figure 34)
In many applications it may be necessary to remove modules or pc boards while the main unit is still operating.
These are considered hot-plug applications. Such implementations require the control of current surges seen
by the main power supply and the card being inserted. The most effective way to control these surges is to limit
and slowly ramp the current and voltage being applied to the card, similar to the way in which a power supply
normally turns on. Due to the controlled rise times and fall times of the TPS2043 and TPS2053, these devices
can be used to provide a softer start-up to devices being hot-plugged into a powered system. The UVLO feature
of the TPS2043 and TPS2053 also ensures the switch will be off after the card has been removed, and the switch
will be off during the next insertion. The UVLO feature guarantees a soft start with a controlled rise time for every
insertion of the card or module.
Power
Supply
2.7 V to 5.5 V
1000 µF
Optimum
0.1 µF
TPS2043
GND1 OC1
IN1 OUT1
EN1 OUT2
EN2 OC2
GND2 OC3
IN2 OUT3
EN3
PC Board
Block of
Circuitry
Block of
Circuitry
Block of
Circuitry
Overcurrent Response
Figure 34. Typical Hot-Plug Implementation
By placing the TPS2043 and TPS2053 between the V_CC input and the rest of the circuitry, the input power will
reach these devices first after insertion. The typical rise time of the switch is approximately 2.5 ms, providing
a slow voltage ramp at the output of the device. This implementation controls system surge currents and
provides a hot-plugging mechanism for any device.
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