AD5410AREZ-REEL7 Analog Devices Inc, AD5410AREZ-REEL7 Datasheet - Page 23

no-image

AD5410AREZ-REEL7

Manufacturer Part Number
AD5410AREZ-REEL7
Description
12Bit Current Source Out DAC
Manufacturer
Analog Devices Inc
Datasheet

Specifications of AD5410AREZ-REEL7

Design Resources
Simplified 12-Bit, 4 mA-to-20 mA Output Solution Using AD5410 (CN0081)
Settling Time
40µs
Number Of Bits
12
Data Interface
DSP, MICROWIRE™, QSPI™, Serial, SPI™
Number Of Converters
1
Voltage Supply Source
Analog and Digital
Power Dissipation (max)
950mW
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
24-TSSOP Exposed Pad, 24-eTSSOP, 24-HTSSOP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD5410AREZ-REEL7
Manufacturer:
ADI/亚德诺
Quantity:
20 000
FEEDBACK/MONITORING OF OUTPUT CURRENT
For feedback or monitoring of the output current value, a sense
resistor can be placed in series with the I
voltage drop across it measured. As well as being an additional
component, the resistor increases the compliance voltage
required. An alternative method is to use a resistor that is
already in place. R3 is such a resistor and is internal to the
AD5410/AD5420, as shown in Figure 46. By measuring the
voltage between the R3
output current can be calculated as follows:
where:
V
and BOOST pins
I
value of 444 μA.
R3 is the resistance value of resistor R3 with a typical value of 40 Ω .
Figure 45. Smoothing Out the Steps Caused by the Digital Slew Rate Control
BIAS
R3
is the voltage drop across R3 measured between the R3
is a constant bias current flowing through R3 with a typical
I
OUT
6.8
6.7
6.6
6.5
6.4
6.3
6.2
6.1
–1
=
V
R
Figure 46. Structure of Current Output Circuit
R
0
3
3
T
AV
R
A
LOAD
I
I
BIAS
1
DD
BIAS
= 25°C
AV
= 24V
SENSE
= 300Ω
DD
2
R
R3
40Ω
444µA
METAL
and BOOST pins, the value of the
Feature
TIME (ms)
3
4
R3
BOOST
I
OUT
NO EXTERNAL CAPS
10nF ON CAP1
10nF ON CAP2
SENSE
OUT
5
output pin and the
6
7
8
SENSE
Rev. B | Page 23 of 28
(2)
R3 and I
coefficient of 30 ppm/°C. Connecting to R3
AV
that have large temperature coefficients and result in large
errors. See Figure 47 for a plot of R3 vs. ambient temperature
and Figure 48 for a plot of R3 vs. output current.
To eliminate errors due to the tolerances of R3 and I
measurement calibration can be performed as the following
example illustrates:
1.
2.
DD
Progam code 0x1000 and measure I
example, the measured values are
I
V
Program Code 0xF000 and measure I
The measured values this time are
I
V
OUT
OUT
avoids incorporating into R3 internal metal connections
40.98
40.96
40.94
40.92
40.90
40.88
40.86
40.84
40.82
40.80
40.78
42.0
41.8
41.6
41.4
41.2
41.0
40.8
40.6
40.4
40.2
40.0
R3
R3
BIAS
= 79.55446 mV
= 946.39628 mV
= 1.47965 mA
= 22.46754 mA
–40
0
T
R3 = V
A
I
R3 = V
both have a tolerance of ±10% and a temperature
OUT
= 25°C
Figure 47. R3 Resistor Value vs. Temperature
= 12mA
R3
–20
R3
/(I
Figure 48. R3 Resistor Value vs. I
/(12mA + 444µA)
OUT
5
+ 444µA)
AMBIENT TEMPERATURE (°C)
0
10
20
I
OUT
(mA)
40
15
AD5410/AD5420
OUT
OUT
60
SENSE
OUT
and V
and V
20
rather than
80
R3
. In this
BIAS
R3
again.
, a two-
100
25

Related parts for AD5410AREZ-REEL7