4.10 Applying the DC Bias Voltage
4-45 ZM2376
DC volt: DC bias voltage input menu is as follows
BIAS Voltage: 0.000V Current setting
0.000V to 5.000V Available ranges
It is possible to set at 1mV in resolution. Enter the numeric value, and press the
_ENTR_
key.
If a setting is made or the EXIT operation is performed, one-previous menu comes back.
The set value of current DC Bias voltage appears on the second line of measurement screen.
• • • • • • 1.500 1.00 V
BIAS Vdc
Restriction between signal level and bias voltage
The peak voltage that can be output by ZM2376 is approx 7.07V.
It is impossible to set when the total of the peak value of AC measurement signal and DC bias
voltage exceeds the above voltage.
If you intend to set the measurement signal level or DC bias voltage beyond the above limit, it will
be set as the permissible maximum value at that moment. When the measurement signal level is
5Vrms, the bias voltage is restricted to 0V. When the DC bias voltage is 5V, the measurement signal
level is restricted to approx 1.4Vrms.
Restriction on charge-discharging current due to DC bias
The peak current that can be output from the H
CUR
terminal by ZM2376 is approx 280mA.
When the total of the peak value of AC measurement signal and the charge-discharging current or
leak current of the DC bias exceeds this current substantially, it causes overload and cannot be
measured correctly.
When the bias voltage is changed substantially while the output impedance is low, a high
charge-discharging current flows. When the measurement signal level exceeds the peak current, the
bias voltage decreases.
Settling time for DC bias voltage
The charge-discharging current at early stage of discharge/charge can be suppressed up to approx
1.4-time that of the max sensing current Ip[Arms] that can be absorbed by the current sensing section
in each measurement range. Therefore, the settling time Ts[s], which is determined by the above
current value, capacitance C (F) of DUT and change Vc[V] in Bias voltage, is needed until it can be
within the limited current range.
Ts C × Vc / ( Ip × 1.4 ).
Max sensing current that can be absorbed by the current sensing section
“Table 3-3 Max. current, max. voltage and output impedance in each measurement range”
However, the measurement range (max sensing current) changes depending of the
measurement frequency.
When the charge-discharging current exceeds this value, since the current beyond the value runs
To Next Page
Loading...
