AD53508 Analog Devices, AD53508 Datasheet - Page 7

• Manufacturer Part Number: AD53508
• Description: PPMU Circuit
• Manufacturer: Analog Devices

IN CURRENT FORCE WITH VOLTAGE MEASURE OR
VERIFY CURRENT FORCE
The linearity tests for forcing current at the FORCE pin:
1. The FORCE pin is loaded with a voltage source.
2. The two ranges of CURRENT FORCE ranges (2 mA and
3. Using these endpoints, gain nonlinearity is computed and
4. Computations for F1 are:
The linearity test for measuring voltage is as follows (at the
MEAS_OUT pin):
1. The endpoints of the linearity curve are determined by the
2. Using these endpoints, gain nonlinearity is computed and
3. Computations for M1 are:
CURRENT FORCE WITH VOLTAGE MEASURE
(2 mA RANGE)
1. DAC1 = 5 V.
2. FORCE pin loaded with 9 V source.
3. Measure current at FORCE.
4. Measure voltage at MEAS_OUT.
5. V
6. Measure current at FORCE and compare to 3.
REV. 0
200 µA) correspond to F1 and F2. The endpoints of the
linearity curve are determined by full scale (or LOW), and
the full scale (or HIGH) readings at the same FORCE pin
voltage.
tested at the 1/4 scale, 1/2 scale, and 3/4 scale points.
F1 × 0.25 = LOW + 1 × (HIGH – LOW)/4
F1 × 0.50 = LOW + 2 × (HIGH – LOW)/4
F1 × 0.75 = LOW + 3 × (HIGH – LOW)/4
Where LOW = –Full Scale and HIGH = +Full Scale.
–full scale (or LOW), and the +full scale (or HIGH) readings.
tested at the 1/4 scale, 1/2 scale, and 3/4 scale points.
M1 × 0.25 = LOW + 1 × (HIGH – LOW)/4
M1 × 0.50 = LOW + 2 × (HIGH – LOW)/4
M1 × 0.75 = LOW + 3 × (HIGH – LOW)/4
Where LOW = –Full Scale, and HIGH = +Full Scale.
CC
= 15 V.
MEAS OUT
VOLTAGE
FORCING
DAC2
DAC1
DSR
CON
2.5V
S1
S6
S7
Figure 3. Guarded Current Force/Voltage Measure, I
ENABLE
OUTPUT
AD53508
S2
S3
VM
IM
SENSE
VF
IF
S4
S5
DIFF
1.25R
1.25R
–7–
MAIN
EXT RC
7. Measure voltage at MEAS_OUT and compare to 4.
8. V
9. DAC1 = 0 V.
10. FORCE pin loaded with –4 V source.
11. Measure current at FORCE.
12. Measure voltage at MEAS_OUT.
13. V
14. Measure current at FORCE and compare to 11.
15. Measure voltage at MEAS_OUT and compare to 12.
16. V
VOLTAGE FORCE WITH CURRENT MEASURE
(2 mA RANGE)
1. DAC1 = 9 V.
2. FORCE pin loaded with 2 mA current source.
3. Measure voltage at FORCE.
4. Measure current at MEAS_OUT.
5. V
6. Measure voltage at FORCE and compare to 3:
7. Measure current at MEAS_OUT and compare to 4:
8. V
9. DAC1 = –4 V.
10. FORCE pin loaded with 2 mA current sink.
11. Measure voltage at FORCE.
12. Measure current at MEAS_OUT.
13. V
14. Measure voltage at FORCE and compare to 11:
15. Measure current at MEAS_OUT and compare to 12.
16. V
R
R
Limit = ± 237 µV.
Limit = ± 237 µV.
Limit = ± 474 µV.
CC
EE
EE
CC
CC
EE
EE
INTEGRATE
200 A
10k
= –9.5 V.
= –10 V.
= –9.5 V.
= –10 V.
= 15 V.
= 14.25 V.
= 15 V.
40pF
S10
2mA
1k
UNITY
RANGE 1
C1
R1
R2
S8
S9
INT/IM
: I ≤ 2 mA
GUARD
S11
S12
S13
S14
S15
S16
S18
S17
SENSE
FORCE
GUARD
AD53508