Vicor PI2121-EVAL1 Full-Function Active ORing Evaluation Board - Manual (Page 9)

Picor Corporation • www.picorpower.com PI2121-EVAL1 User Guide Rev 1.1 Page 9 of 12
8.0 Internal MOSFET Rds(on) Measurement:
8.1 The SiP1 internal MOSFET Rds(on) can be measured
with a voltmeter between the S1 and D1 Kelvin
connection. The potential between S1 and D1 is
the voltage drop across the internal MOSFET and:
Rds(on) = V
S1
–V
D1
I
in
Where:
V
S1
–V
D1
: Voltage drop across the internal MOSFET
I
in
: Input current.
Note: The Rds(on) value is temperature dependent and the
junction temperature increases directly proportional to
power dissipation.
Thermal Images
Figure 7a – PI2121 mounted on PI2121-EVAL1, Iout=24 A,
TA=25°C, Air Flow=0 LFM
Figure 7b – PI2121 mounted on PI2121-EVAL1 Iout=24 A,
TA=25°C, Air Flow=200 LFM