Datasheet
Table Of Contents
- FEATURES
- DESCRIPTION
- FUNCTIONAL BLOCK DIAGRAMS
- DETAILED DESCRIPTION
- ABSOLUTE MAXIMUM RATINGS
- DISSIPATION RATING TABLE
- RECOMMENDED OPERATING CONDITIONS
- ELECTRICAL CHARACTERISTICS OVER RECOMMENDED OPERATING JUNCTION TEMPERATURE RANGE
- ENABLE INPUT ENx OR ENx
- CURRENT LIMIT
- SUPPLY CURRENT (TPS2045A, TPS2055A)
- SUPPLY CURRENT (TPS2046A, TPS2056A)
- SUPPLY CURRENT (TPS2047A, TPS2057A)
- SUPPLY CURRENT (TPS2048A, TPS2058A)
- UNDERVOLTAGE LOCKOUT
- OVERCURRENT OC
- PARAMETER MEASUREMENT INFORMATION
- TYPICAL CHARACTERISTICS
- APPLICATION INFORMATION
- POWER-SUPPLY CONSIDERATIONS
- OVERCURRENT
- OC RESPONSE
- POWER DISSIPATION AND JUNCTION TEMPERATURE
- THERMAL PROTECTION
- UNDERVOLTAGE LOCKOUT (UVLO)
- UNIVERSAL SERIAL BUS (USB) APPLICATIONS
- HOST/SELF-POWERED AND BUS-POWERED HUBS
- LOW-POWER BUS-POWERED FUNCTIONS AND HIGH-POWER BUS-POWERED FUNCTIONS
- USB POWER-DISTRIBUTION REQUIREMENTS
- GENERIC HOT-PLUG APPLICATIONS (see )
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GENERIC HOT-PLUG APPLICATIONS (see Figure 31 )
Power
Supply
Block of
Circuitry
TPS2045A
GND
IN
IN
EN
OUT
OUT
OUT
OC
0.1 µF
1000 µF
Optimum
2.7 V to 5.5 V
PC Board
Overcurrent Response
TPS2045A , , TPS2046A
TPS2047A , TPS2048A , TPS2055A
TPS2056A , TPS2057A , TPS2058A
SLVS251C – SEPTEMBER 2000 – REVISED JANUARY 2008
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.
Figure 31. Typical Hot-Plug Implementation (Example, TPS2045A)
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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Product Folder Link(s): TPS2045A TPS2046A TPS2047A TPS2048A TPS2055A TPS2056A TPS2057A TPS2058A