Texas Instruments TPS78225EVM-445 Evaluation Module TPS78225EVM-445 TPS78225EVM-445 Datenbogen
Produktcode
TPS78225EVM-445
2.1
Input / Output Connector Descriptions
2.1.1
J1 –VIN
2.1.2
J2 –VOUT
2.1.3
J3 – GND
2.1.4
J4 – GND
2.1.5
JP1 – ENABLE
3
Operation
3.1
Operating the TPS782xxEVM
4
Thermal Guidelines
4.1
Thermal Considerations
T = T
+ P x
J
A
d
θ
JA
(1)
Operation
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This is the positive input supply voltage. The leads to the input supply must be twisted and kept as short
as possible to minimize EMI transmission. Additional bulk capacitance must be added between J1 and J2
if the supply leads are greater than six inches. An additional 47-
as possible to minimize EMI transmission. Additional bulk capacitance must be added between J1 and J2
if the supply leads are greater than six inches. An additional 47-
µ
F or greater capacitor improves the
transient response of the TPS782xx and helps to reduce ringing on the input when long supply wires are
used.
used.
This is the positive connection from the output. Connect this pin to the positive input of the load.
This is the return connection for the input power supply of the regulator.
This is the return connection for the output.
This jumper is used to enable or disable the TPS782xx. Shorting pins 1 and 2 together (ON and the
middle pin) enables the regulator. Shorting pins 2 and 3 (middle pin and OFF) disables the regulator. This
input must not be left floating.
middle pin) enables the regulator. Shorting pins 2 and 3 (middle pin and OFF) disables the regulator. This
input must not be left floating.
This section provides information about the operation of the TPS782xxEVM.
Connect the positive input power supply to J1. Connect the input power return (ground) to J3. The
TPS782xxEVM has an absolute maximum input voltage of 6 V. The recommended maximum operating
voltage is 5.5 V. The actual highest input voltage may be less than 5.5 V due to thermal conditions. See
the Thermal Considerations section of this manual to determine if the highest input voltage.
TPS782xxEVM has an absolute maximum input voltage of 6 V. The recommended maximum operating
voltage is 5.5 V. The actual highest input voltage may be less than 5.5 V due to thermal conditions. See
the Thermal Considerations section of this manual to determine if the highest input voltage.
Connect the desired load between J2 (positive lead) and J4 (negative or current return lead). Apply the
input power and configure jumper JP1 to enable or disable the regulator.
input power and configure jumper JP1 to enable or disable the regulator.
This section provides guidelines for the thermal management of the TPS782xxEVM-445 board.
Thermal management is a key component of design of any power converter and is especially important
when the power dissipation in the LDO is high. To better help you design the TPS782xx family into your
application, use the following formula to approximate the maximum power dissipation at a particular
ambient temperature:
when the power dissipation in the LDO is high. To better help you design the TPS782xx family into your
application, use the following formula to approximate the maximum power dissipation at a particular
ambient temperature:
where T
J
is the junction temperature, T
A
is the ambient temperature, P
d
is the power dissipation in the IC
and
θ
JA
is the thermal resistance from junction to ambient. All temperatures are in degrees Celsius.
2
TPS782xxEVM
SLVU294 – February 2009