Texas Instruments Evaluation Module for Positive Voltage, Power-Limiting Hotswap Controller TPS24710EVM-003 TPS24710EVM-003 데이터 시트
제품 코드
TPS24710EVM-003
LOAD CURRENT
PATH
R
SENSE
LOAD CURRENT
PATH
M0217-02
Method 2
TPS2471x
SENSE
VCC
Method 1
SENSE
VCC
TPS2471x
SLVSAL2E – JANUARY 2011 – REVISED NOVEMBER 2013
Bypass Capacitors
It is a good practice to provide low-impedance ceramic capacitor bypassing of the VCC and OUT pins. Values in
the range of 10 nF to 1 µF are recommended. Some system topologies are insensitive to the values of these
capacitors; however, some are not and require minimization of the value of the bypass capacitor. Input
capacitance on a plug-in board may cause a large inrush current as the capacitor charges through the low-
impedance power bus when inserted. This stresses the connector contacts and causes a short voltage sag on
the input bus. Small amounts of capacitance (e.g., 10 nF to 0.1 µF) are often tolerable in these systems.
It is a good practice to provide low-impedance ceramic capacitor bypassing of the VCC and OUT pins. Values in
the range of 10 nF to 1 µF are recommended. Some system topologies are insensitive to the values of these
capacitors; however, some are not and require minimization of the value of the bypass capacitor. Input
capacitance on a plug-in board may cause a large inrush current as the capacitor charges through the low-
impedance power bus when inserted. This stresses the connector contacts and causes a short voltage sag on
the input bus. Small amounts of capacitance (e.g., 10 nF to 0.1 µF) are often tolerable in these systems.
Output Short-Circuit Measurements
Repeatable short-circuit testing results are difficult to obtain. The many details of source bypassing, input leads,
circuit layout and component selection, output shorting method, relative location of the short, and instrumentation
all contribute to variation in results. The actual short itself exhibits a certain degree of randomness as it
microscopically bounces and arcs. Care in configuration and methods must be used to obtain realistic results. Do
not expect to see waveforms exactly like those in this data sheet; every setup differs.
Repeatable short-circuit testing results are difficult to obtain. The many details of source bypassing, input leads,
circuit layout and component selection, output shorting method, relative location of the short, and instrumentation
all contribute to variation in results. The actual short itself exhibits a certain degree of randomness as it
microscopically bounces and arcs. Care in configuration and methods must be used to obtain realistic results. Do
not expect to see waveforms exactly like those in this data sheet; every setup differs.
Layout Considerations
TPS24710/11/12/13 applications require careful attention to layout to ensure proper performance and to minimize
susceptibility to transients and noise. In general, all traces should be as short as possible, but the following list
deserves first consideration:
•
TPS24710/11/12/13 applications require careful attention to layout to ensure proper performance and to minimize
susceptibility to transients and noise. In general, all traces should be as short as possible, but the following list
deserves first consideration:
•
Decoupling capacitors on VCC pin should have minimal trace lengths to the pin and to GND.
•
Traces to VCC and SENSE must be short and run side-by-side to maximize common-mode rejection. Kelvin
connections should be used at the points of contact with R
connections should be used at the points of contact with R
SENSE
. (see
•
Power path connections should be as short as possible and sized to carry at least twice the full load current,
more if possible.
more if possible.
•
Protection devices such as snubbers, TVS, capacitors, or diodes should be placed physically close to the
device they are intended to protect, and routed with short traces to reduce inductance. For example, the
protection Schottky diode shown in the typical application diagram on the front page of this data sheet should
be physically close to the OUT pin.
device they are intended to protect, and routed with short traces to reduce inductance. For example, the
protection Schottky diode shown in the typical application diagram on the front page of this data sheet should
be physically close to the OUT pin.
Figure 37. Recommended R
SENSE
Layout
Copyright © 2011–2013, Texas Instruments Incorporated
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