17-3
IM DLM3054-01EN
Measurement Setup (Measure Setup)
The loss of multiple cycles can be measured. The measurement time period is the range specified by the T
Range1 and T Range2 cursors. The cycle is determined on the basis of the intersections of the mesial level and
the voltage waveform. Then, the loss for multiple cycles is measured. The total loss that is corrected depending
on the type of loss (described later) can also be measured.
u(t): Sampled voltage data
i(t): Sampled current data
T
c2
Tc
1
T
c2
Tc
1
u(t)
•
i(t) dt
Loss =
u(t)
•
i(t) dt
Loss per unit time =
1
Tc
U(CH1)
I(CH2)
U x I(Math)
Mesial
Multiple cycles Tc
T1
(T Range1)
T2
(T Range2)
T
c2
T
c1
Specified range
If the specified period does not contain one cycle of waveform, the measured value is displayed as “*****.”
Type of Loss (Conduction Calc)
Select the type of loss to be measured from one of the settings below.
U x I: The loss according to the aforementioned equation.
RDS(on) x I
2
: The loss over the loss calculation period on the basis of the device’s on-resistance, RDS(on).
VCE(sat) x I: The loss over the loss calculation period on the basis of the device’s collector-emitter saturation
voltage, Vce(SAT).
If the type of loss is set to RDS(on) x I
2
or VCE(sat) x I, the total loss is measured according to the following.
Total loss = Loss in the loss calculation loss in the switching period
U(CH1)
I(CH2)
U x I(Math)
Zero loss period
Loss calculation
period (On)
U
Level
I
Level
Mesial
Switching period
(positive) (Turn On)
Switching period
(negative) (Turn Off)
Loss is measured
with adjustment
according to the
type of loss.
The current is
assumed to be zero.
Thus, the loss is
zero.
In the switching
period, the
instrument
measures the
loss using the
sampled voltage
and current data,
regardless of the
type of loss.
Loss
measurement in
each period
Included in the
loss calculation
period, not in the
switching period
Included in the
zero loss period,
not in the
switching period
T
L11
T
L21
T
Ln1
T
s11
T
s21
T
sn1
T
s12
T
s22
T
sn2
T
L12
T
L22
T
Ln2
T
s14
T
s24
T
sn4
T
s13
T
s23
T
sn3
17 Power Supply Analysis Feature (Power Analysis and Power Measurement, Option)