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88
PFX2512_CE
A
Features of the Digital CC/CV Control
The digital control is adopted to control the operation of constant current (CC) and the constant
voltage (CV) .
To perform the efficient evaluation test, the following describes the feature and the principle of
operation for the digital control of the CC/CV operation .
Features of the digital CC / CV control
●
Enables to keep a high precision of the CC/CV control with less effect of the specification
of the connected DC power supply and the Electronic load.
●
The adjustment is not required for the system between the DC power supply and the
Electronic load.
●
The accurate efficiency of the charge and discharge can be measured with less
discrepancy in the measurement performance of the charging capacity and discharging
capacity.
Description of operation
As an example of the digital CC control under the charging state, the principle of operation is
described as follows.
In the constant current charging operation, when the setting value of the CC is forwarded to the
PID control section and the operation starts, the PID control function increases the amount of the
current control applied to the DC power supply (PWR800L). At this time, the charging current is
measured by the high-precision shunt, and the digital current measurement value is acquired by
the 24-bit AD converter. The PID control function compares the digital CC setting value and the
digital current measurement value, and calculate the amount the amount of the current control to
become equal. Each sequence of this operation performs 1000 times per second.
= Integrated functions in PFX2512
High accuracy
current
measurement
CC setting value
Measured current value
= calculate the control value
every 1 ms to be equal to
the "CC setting value"
(PID control function)
AD converter
(24 bitADC)
DUT
(battely)
DC power supply (PWR800L)
Amount of current control
(CC reference)
Digital current
measurement
value
Digital
CC setting value
Analog value
High accuracy
shunt
Electronid load (PLZ1004W)
Load switch
(Power MOSFET)
Charge current
Discharge current
The system figure of the digital CC control (Model ID: 7101 for the charge state)