Analog Devices AD5522 Evaluation Board EVAL-AD5522EBUZ EVAL-AD5522EBUZ データシート
製品コード
EVAL-AD5522EBUZ
AD5522
Data Sheet
Rev. E | Page 40 of 64
CIRCUIT OPERATION
FORCE VOLTAGE (FV) MODE
Most PMU measurements are performed in force voltage/measure
current (FVMI) mode, for example, when the device is used as a
device power supply, or in continuity or leakage testing. In force
voltage (FV) mode, the voltage forced is mapped directly to the
DUT. The measure voltage amplifier completes the loop, giving
negative feedback to the forcing amplifier (see Figure 54).
current (FVMI) mode, for example, when the device is used as a
device power supply, or in continuity or leakage testing. In force
voltage (FV) mode, the voltage forced is mapped directly to the
DUT. The measure voltage amplifier completes the loop, giving
negative feedback to the forcing amplifier (see Figure 54).
The forced voltage can be calculated as follows:
Forced Voltage at DUT = VOUT
VOUT = 4.5 × VREF × (DAC_CODE/2
VOUT = 4.5 × VREF × (DAC_CODE/2
16
) − (3.5 × VREF ×
(OFFSET_DAC_CODE/2
16
)) + DUTGND
where:
VOUT is the voltage of the FIN DAC (see the DAC Levels
section).
section).
DUTGND
MEASVHx
DUT
R
SENSE
(UP TO
±80mA)
±80mA)
R
SENSE
EXTMEASIHx
EXTMEASILx
FOHx
EXTFOHx
CFFx
FIN
FORCE
AMPLIFIER
INTERNAL RANGE SELECT
(±5µA, ±20µA, ±200µA, ±2mA)
DAC
–
–
–
–
–
–
+
+
+
–
+
+
+
+
×5 OR
×10
×1
AGND
MEASURE VOLTAGE AMPLIFIER
MEASOUTx
VMID TO
CENTER
I RANGE
CENTER
I RANGE
06197-
033
×1 OR
×0.2
4k
Ω
2kΩ
4k
Ω
Figure 54. Forcing Voltage, Measuring Current