TPS2041A_15 Datasheet, PDF (28/34 Pages) Texas Instruments – CURRENT-LIMITED POWER-DISTRIBUTION SWITCHES

TPS2041A, TPS2042A, TPS2043A, TPS2044A
TPS2051A, TPS2052A, TPS2053A, TPS2054A
CURRENT-LIMITED POWER-DISTRIBUTION SWITCHES
SLVS247 – SEPTEMBER 2000
APPLICATION INFORMATION
generic hot-plug applications (see Figure 33)
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 TPS204xA and TPS205xA, 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 TPS204xA and TPS205xA 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 insures 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
PC Board
0.1 µF
TPS2041A
GND OUT
IN
OUT
IN
OUT
EN
OC
Block of
Circuitry
Overcurrent Response
Figure 33. Typical Hot-Plug Implementation (Example, TPS2041A)
By placing the TPS204xA and TPS205xA 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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