AD5522JSVDZ Analog Devices Inc, AD5522JSVDZ Datasheet - Page 41

• Manufacturer Part Number: AD5522JSVDZ
• Description: IC, DAC, 16BIT, QFP-80
• Manufacturer: Analog Devices Inc

Specifications of AD5522JSVDZ

• Resolution (bits): 16bit
• Input Channel Type: Serial
• Supply Voltage Range - Digital: 2.3V To 5.25V
• Supply Current: 36mA
• Digital Ic Case Style: QFP
• No. Of Pins: 80
• Data Interface: LVDS, Serial
• Design Resources: Parametric Measurement Unit and Supporting Components for PAD Appls Using AD5522 and AD7685 (CN0104)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FORCE CURRENT (FI) MODE
In force current (FI) mode, the voltage at the FIN DAC is
converted to a current and is applied to the DUT. The feedback
path is the measure current amplifier, feeding back the voltage
measured across the sense resistor. MEASOUTx reflects the
voltage measured across the DUT (see Figure 55).
For the suggested current ranges, the maximum voltage drop
across the sense resistors is ±1 V. However, to allow for error
correction, there is some overrange available in the current
ranges. The maximum full-scale voltage range that can be
loaded to the FIN DAC is ±11.5 V. The forced current can be
calculated as follows:
FI = 4.5 × VREF × ((DAC_CODE − 32,768)/2
MI_Amplifier_Gain)
MEASOUTx
×1 OR
×0.2
VMID TO
I RANGE
CENTER
DAC
AGND
Figure 55. Forcing Current, Measuring Voltage
16
FIN
×5 or ×10
)/(R
MEASURE CURRENT
×1
+
–
+
SENSE
–
AMPLIFIER
+
–
AMPLIFIER
FORCE
Rev. D | Page 41 of 64
×
+
–
+
–
+
–
+
–
(±5µA, ±20µA, ±200µA, ±2mA)
INTERNAL RANGE SELECT
where:
FI is the forced current.
R
MI_Amplifier_Gain is the gain of the measure current
instrumentation amplifier. This gain can be set to 5 or
10 via the serial interface.
The I
such a way as to center the measure current output regardless of
the voltage span used.
In the ±200 μA range with the 5 kΩ sense resistor and an I
gain of 10, the maximum current range possible is ±225 μA.
Similarly, for the other current ranges, there is an overrange of
12.5% to allow for error correction.
SENSE
R
SENSE
SENSE
is the selected sense resistor.
amplifier is biased by the offset DAC output voltage in
2kΩ
4k Ω
4k Ω
EXTMEASIHx
MEASVHx
DUTGND
EXTFOHx
CFFx
FOHx
EXTMEASILx
DUT
R
(UP TO
±80mA)
SENSE
AD5522
SENSE