Setup
5.15 R
ON
Test Procedure
1. Setup the EVM per
2. Set SOURCE1 level to 5.0 V.
3. Place a shunt across JP1 from pin1 to pin2.
4. Connect ON1 and ON2 to a DC source between 1.2 V and 5.5 V, SOURCE1 supply can be used for
this. (When testing R
ON
it is desired to have the switch operating in the always ON condition.)
5. Place a load on VOUT1 and VOUT2.
6. Turn on SOURCE1.
7. Record the voltage reading from METER1 and METER2 as well as the input current reading from
SOURCE1.
8. Turn SOURCE1 off.
9. Calculate the R
ON
value for switch 1 by dividing the METER1 voltage level by half of the current
reading from SOURCE1.
10. Calculate the R
ON
value for switch 2 by dividing the METER2 voltage level by half of the current
reading from SOURCE1.
5.16 t
R
, t
ON
, t
F
, t
OFF
Test Procedure
1. The rise time (t
R
) is selected by the CT capacitor value on each switch channel. The EVM is shipped
with a default CT value of 1 nF.
2. Set up the EVM per
3. Set SOURCE1 level to 5.0 V.
4. Place a shunt across JP1 from pin1 to pin2.
5. Place a load on VOUT1 and VOUT2 (a 10
Ω
, 3.25 W resistor is recommended for this test).
6. Set Signal Generator output to 0–2 Vpp, 10–100 Hz, and 25% duty cycle.
7. Turn SOURCE1 on.
8. Enable the Signal Generator output.
9. Rise time (t
R
) and turn-on time (t
ON
) can be observed with a Oscilloscope sync the scope trigger on the
rising edge of the on signal.. A detailed description of t
R
, t
ON
, t
F
and t
OFF
are listed in the
TPS22968/68N-Q1 Datasheet under the Switching Characteristics Section.
10. Fall time (t
F
) and turn-off time (t
OFF
) can be observed from the oscilloscope by charging the scope
triggering to sync with the falling edge of the ON signal.
11. Turn SOURCE1 off and disable the signal Generator output.
8
TPS22968/68N-Q1 Dual Channel, 5.5-V, 4-A, 27-m
Ω
Load Switch Evaluation
SLVUAE2A – January 2015 – Revised November 2015
Module
Copyright © 2015, Texas Instruments Incorporated