ADR02BR Analog Devices Inc, ADR02BR Datasheet - Page 16

• Manufacturer Part Number: ADR02BR
• Description: Voltage Reference
• Manufacturer: Analog Devices Inc

Specifications of ADR02BR

• Peak Reflow Compatible (260 C): No
• Output Voltage: 5V
• Leaded Process Compatible: No
• Mounting Type: Surface Mount
• Package / Case: SOIC
• Rohs Status: RoHS non-compliant
• Design Resources: High Accuracy, Bipolar Voltage Output Digital-to-Analog Conversion Using AD5764 (CN0006) 4 mA to 20 mA Process Control Loop Using AD5662 (CN0009) 16-Bit Fully Isolated Voltage Output Module Using AD5662, ADuM1401, and External Amplifiers (CN0063) 16-Bit Fully Isolated 4 mA to 20 mA Output Module Using AD5662, ADuM1401, and External Amplifiers (CN0064)
• Reference Type: Series
• Voltage - Output: 5V
• Tolerance: ±0.06%
• Temperature Coefficient: 3ppm/°C
• Voltage - Input: 7 ~ 36 V
• Number Of Channels: 1
• Current - Quiescent: 1mA
• Current - Output: 10mA
• Operating Temperature: -40°C ~ 125°C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Cathode: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

ADR01/ADR02/ADR03/ADR06
The TEMP function is provided as a convenience rather than a
precise feature. Because the voltage at the TEMP node is
acquired from the band gap core, current pulling from this pin
has a significant effect on V
TEMP output with a suitable low bias current op amp, such as
the AD8601, AD820, or OP1177, all of which result in less than
a 100 µV change in ∆V
even tens of microamps drawn from the TEMP pin can cause
V
LOW COST CURRENT SOURCE
Unlike most references, the ADR01/ADR02/ADR03/ADR06
employ an NPN Darlington in which the quiescent current
remains constant with respect to the load current, as shown in
Figure 23. As a result, a current source can be configured as
shown in Figure 38 where I
the sum of I
0.55 mA to 0.65 mA, limiting this circuit to general-purpose
applications.
OUT
to fall out of specification.
0.80
0.70
0.60
0.55
0.50
0.45
0.40
0.75
0.65
–50
1.9mV/°C
V
SAMPLE SIZE = 5
SET
V
Figure 36. Voltage at TEMP Pin vs. Temperature
IN
TEMP
= 15V
and I
–25
Figure 37. Temperature Monitoring
Q
. Although simple, I
U2
OUT
0
OP1177
15V
TEMPERATURE (°C)
(see Figure 37). Without buffering,
V+
V–
SET
OUT
V
25
IN
= (V
. Care must be taken to buffer the
OUT
50
ΔV
V
TEMP TRIM
ADR01/
ADR02/
ADR03/
ADR06
IN
− V
TEMP
GND
U1
Q
V
L
/ΔT ≈ 1.96mV/°C
varies typically from
)/R
OUT
75
SET
. I
100
V
L
O
is simply
125
Rev. O | Page 16 of 20
PRECISION CURRENT SOURCE WITH
ADJUSTABLE OUTPUT
Alternatively, a precision current source can be implemented
with the circuit shown in Figure 39. By adding a mechanical or
digital potentiometer, this circuit becomes an adjustable current
source. If a digital potentiometer is used, the load current is
simply the voltage across Terminal B to Terminal W of the
digital potentiometer divided by R
where D is the decimal equivalent of the digital potentiometer
input code.
To optimize the resolution of this circuit, dual-supply op amps
should be used because the ground potential of ADR02 can
swing from −5.0 V at zero scale to V
potentiometer setting.
I
L
+12V
=
Figure 39. Programmable 0 mA to 5 mA Current Source
V
ADR01/
ADR02/
ADR03/
ADR06
REF
R
SET
×
GND
V
D
V
TEMP TRIM
IN
Figure 38. Low Cost Current Source
ADR01/
ADR02/
ADR03/
ADR06
IN
I
GND
Q
V
U1
–5V TO V
I
OUT
≈ 0.6mA
IN
V
OUT
R
L
AD5201
SET
0V TO (5V + V
R
U2
OP1177
100kΩ
L
+12V
–12V
V+
V–
A
B
V
SET
L
I
I
L
SET
L
.
W
= I
at full scale of the
L
)
= (V
SET
R
OUT
+ I
SET
R
Q
L
– V
L
1kΩ
1kΩ
)/R
V
SET
L
I
L
(1)