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TPL7407LEVM Performance Testing Using Lab Equipment
The TPL7407Loutput pins 16 to 10 are connected to relays RL1 to RL7 and J2-Output port pins 1 -7 (pin 8
is relay coil power sense).
The TPL7407LCOM, pin 9, is connected to the relay supply on TB1. This pin connects to the cathodes of
free wheeling diodes for each output. It provides a discharge path when the inductive load is turned off.
The inputs can be fully controlled by external test equipment using the J1-Input Port. The outputs can be
measured by external test equipment using the J2-Output Port. If relay supply voltage, TPL7407L COM
pin, exceeds 40V or full external control is required, then the relay coils should be disconnected by
removing the zero ohm resistors labeled R41 to R47.
The TPL7407LEVM has open 0603 foot prints for input resistors to ground as R11 to R17, coil wave
shaping resistor and capacitors as R31 to R37 and C31 to C37. The TPL7407L does not require these
components.
Increasing output load using onboard relays: Shorting two or more of the J2 pins 1-7 (output port) will
parallel the TPL7407Loutputs and relay coils. By activate just one of the inputs for the shorted output
channels will cause a single output to drive multiple relay coil loads. Two coils typically uses 16.6mA and
three coils typically use 24.9mA.
4
TPL7407LEVM Performance Testing Using Lab Equipment
Datasheet electrical characterization parameters can be measured using the following test setups. Setups
for both standard EVM boards and modified EVM boards that have R41 to R47 removed to disconnect the
onboard relay loads. It is acceptable to keep some channels “standard” (R4x installed) and other channels
“modified” (R4x removed). The capacitors (470µF & 0.1µF) on the TPL7407L COM pin are connected
regardless of R41 to R47 presence. Therefore the charging, discharging, and leakages of the capacitors
must be considered. Each output pin has an internal diode to the COM pin. Testing for channel 1 will be
described; test other channels by using a different pin on the J1(input) and J2(output) connectors.
Channel Tested
J1(Input)-pin
J2(Output)-pin
CH 1
J1–1
J2–1
CH 2
J1–2
J2–2
CH 3
J1–3
J2–3
CH 4
J1–4
J2–4
CH 5
J1–5
J2–5
CH 6
J1–6
J2–6
CH 7
J1–7
J2–7
Relay supply is connected to TB1 pin 4; the Relay supply sense line can also be connected to TB1-pin4.
Alternatively the sense line can be connected to J2 pin 8. The relay supply is the same node as the
TPL7407LCOM (pin 9).
Ground power and ground sense connection can be made to TB1 pins 2 and 3. An alternative ground
sense can be made at J1 pin 8.
Warning: All tests that supply current should be limited to the data sheet limit of 600mA. Input pin
voltage should be limited to 30V and output pin voltage should be limited to 40V.
5
SLRU005 – February 2013
TPL7407L7-Channel Relay and Inductive Load Sink Driver EVM
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