AD420ARZ-32 Analog Devices Inc, AD420ARZ-32 Datasheet - Page 10

• Manufacturer Part Number: AD420ARZ-32
• Description: IC DAC SRL 16BIT 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD420ARZ-32

• Data Interface: Serial
• Settling Time: 2.5µs
• Number Of Bits: 16
• Number Of Converters: 1
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 176mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Resolution (bits): 16bit
• Sampling Rate: 400SPS
• Input Channel Type: Serial
• Supply Current: 4.2mA
• Digital Ic Case Style: SOIC
• No. Of Pins: 24
• Number Of Channels: 1
• Resolution: 16b
• Conversion Rate: 0.4KSPS
• Interface Type: SERIAL 3W SPI UW
• Single Supply Voltage (typ): 15/18/24V
• Dual Supply Voltage (typ): Not RequiredV
• Architecture: Delta-Sigma
• Power Supply Requirement: Single
• Output Type: Current/Voltage
• Integral Nonlinearity Error: ±0.012LSB
• Single Supply Voltage (min): 12V
• Single Supply Voltage (max): 32V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 24
• Package Type: SOIC W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

AD420
APPLICATIONS INFORMATION
CURRENT OUTPUT
The AD420 can provide 4 mA–20 mA, 0 mA–20 mA, or 0 mA–
24 mA output without any active external components. Filter
capacitors C1 and C2 can be any type of low cost ceramic
capacitors. To meet the specified full-scale settling time of 3 ms,
low dielectric absorption capacitors (NPO) are required.
Suitable values are C1 = 0.01 μF and C2 = 0.01 μF.
DRIVING INDUCTIVE LOADS
When driving inductive or poorly defined loads ,connect a 0.01 μF
capacitor between I
stability of the AD420 with loads beyond 50 mH. There is no
maximum capacitance limit. The capacitive component of the
load may cause slower settling, though this may be masked by
the settling time of the AD420. A programmed change in the
current may cause a back EMF voltage on the output that may
exceed the compliance of the AD420. To prevent this voltage
from exceeding the supply rails connect protective diodes
between I
VOLTAGE-MODE OUTPUT
Since the AD420 is a single supply device, it is necessary to add
an external buffer amplifier to the V
of bipolar output voltage ranges as shown in Figure 7.
DATA IN
CLOCK
SELECT 1
SELECT 2
CLEAR
LATCH
SELECT 1
SELECT 2
DATA IN
RANGE
RANGE
RANGE
RANGE
CLOCK
CLEAR
LATCH
0.1µF
0.1µF
OUT
REF OUT
and each of V
5
4
6
7
8
9
REF OUT
5
4
6
7
8
9
V
Figure 6. Standard Configuration
LL
2
OUT
V
14
LL
2
C1
(Pin 18) and GND (Pin 11). This ensures
14
20
C1
AD420
15
20
AD420
C2
CC
REF IN
Figure 7.
15
C2
and GND.
21
REF IN
21
V
CC
V
23
11
CC
OUT
23
GND
11
0.1µF
pin to obtain a selection
17
GND
V
R1
0.1µF
18
OUT
I
OUT
R
(4mA TO 20mA)
R2
LOAD
R3
V
OUT
Rev. H | Page 10 of 16
Table 7. Buffer Amplifier Configuration
R1
Open
Open
R
R
Suitable R = 5 kΩ.
OPTIONAL SPAN AND ZERO TRIM
For users who would like lower than the specified values of
offset and gain error, Figure 8 shows a simple way to trim these
parameters. Care should be taken to select low drift resistors
because they affect the temperature drift performance of
the DAC.
The adjustment algorithm is iterative. The procedure for
trimming the AD420 in the 4 mA–20 mA mode can be
accomplished as follows:
1.
2.
Return to Step I and iterate until convergence is obtained.
Variation of RZERO between REF OUT (5 V) and GND leads
to an offset adjust range from −1.5 mA to 6 mA, (1.5 mA/V
centered at 1 V).
The 5 kΩ RSPAN2 resistor is connected in parallel with the
internal 40 W sense resistor, which leads to a gain increase of
+0.8%.
As RSPAN is changed to 500 Ω, the voltage on REF IN is
attenuated by the combination of RSPAN and the 30 kΩ REF IN
input resistance. When added together with RSPAN2 this
results in an adjustment range of −0.8% to +0.8%.
DATA IN
CLOCK
CLEAR
LATCH
0.1µF
SELECT 1
SELECT 2
Offset adjust. Load all zeros. Adjust RZERO for
4.00000 mA of output current.
Gain adjust. Load all ones. Adjust RSPAN for 19.99976 mA
(FS − 1 LSB) of output current.
RANGE
RANGE
REF OUT
5
4
6
7
8
9
R2
Open
R
Open
2R
Figure 8. Offset and Gain Adjust
V
14
LL
2
RSPAN
500Ω
C1
20
AD420
15
C2
RZERO
21
10kΩ
16
R3
0
R
R
2R
23
GND
11
V
CC
19
18
I
OUT
BOOST
5kΩ
RSPAN2
V
0 V − 5 V
±5 V
±10 V
R
(4mA TO 20mA)
LOAD
OUT
0.1µF