17-4
IM DLM3054-01EN
• Loss calculation period: The period from the point where the voltage waveform goes below the U Level
immediately after the waveform goes below the mesial level to the point where the waveform goes above the
U Level immediately before the waveform goes above the mesial level.
Loss in the loss calculation period
When the type of loss is RDS(on) x I2,
i(t)
2
dt + i(t)
2
dt …+ i(t)
2
dt
{
{
T
L11
T
L12
T
L21
T
L22
T
Ln1
T
Ln2
If there are n voltage waveform cycles between the T Range1 and T Range2 cursors
= RDS(on)
RDS(on): On-resistance
Vce(SAT): Collector-emitter saturation voltage
i(t):
Sampled current data
T
L11
, T
L12
, T
L21
, T
L22
…T
Ln1
, T
Ln2
: Time values in the loss calculation period
Loss in the loss calculation period
When the type of loss is VCE(sat) x I,
i(t) dt + i(t) dt …+ i(t) dt
{
{
T
L11
T
L12
T
L21
T
L22
T
Ln1
T
Ln2
= Vce(SAT)
• Zero loss period: The period from the point where the current waveform first goes below the I Level after the
waveform passes the middle point of the loss calculation period to the point where the waveform first goes
above the I Level after the waveform passes the middle point between the relevant loss calculation period and
the next loss calculation period. The instrument assumes that the current and loss are zero.
• Switching period: The period other than the loss calculation period or zero loss period described above.
Positive switching period is the period in which the current waveform is rising; negative switching period is
that in which the current waveform is falling.
u(t): Sampled voltage data
i(t): Sampled current data
T
s11
, T
s12
, T
s13
, T
s14
, T
s21
, T
s22
, T
s23
, T
s24
…T
sn1
, T
sn2
, T
sn3
, T
sn4
:
Time values in the switching period
Loss in the switching period
= u(t)
•
i(t) dt + u(t)
•
i(t) dt + u(t)
•
i(t) dt + u(t)
•
i(t) dt …+ u(t)
•
i(t) dt + u(t)
•
i(t) dt
T
s11
T
s12
T
s13
T
s14
T
s21
T
s22
T
s23
T
s24
T
sn3
T
sn4
T
sn1
T
sn2
If there are n voltage waveform cycles between the T Range1 and T Range2 cursors,
there are 2n switching periods.
17 Power Supply Analysis Feature (Power Analysis and Power Measurement, Option)
