REF02AZ/883C AD [Analog Devices], REF02AZ/883C Datasheet - Page 11

• Manufacturer Part Number: REF02AZ/883C
• Description: 5 V Precision Voltage Reference/Temperature Transducer
• Manufacturer: AD [Analog Devices]

REFERENCE STACK WITH EXCELLENT LINE
REGULATION
Two REF01s and one REF02 can be stacked to yield 5.000 V,
15.000 V, and 25.000 V outputs. An additional advantage is
near-perfect line regulation of the 5.0 V and 15.0 V output. A 27
V to 55 V input change produces an output change that is less
than the noise voltage of the devices. A load bypass resistor
(RB) provides a path for the supply current (I
regulator.
In general, any number of REF01s and REF02s can be stacked
this way. For example, 10 devices will yield 10 outputs in 5 V or
10 V steps. The line voltage can change from 100 V to 130 V.
However, care must be taken to ensure that the total load
currents do not exceed the maximum usable current (typically
21 mA).
NOTES
1. REF02 SHOULD BE THERMALLY CONNECTED
2. NUMBERS IN PARENTHESES ARE FOR A
3. R3 = R1 || R2 || R6
ELEMENT
HEATING
TO SUBSTANCE BEING HEATED.
SETPOINT TEMPERATURE OF 60°C.
1.9mV/°C
V
TEMP
(SEE NOTE 1)
2.2kΩ
V+ (12V TO 32V)
Figure 19. Temperature Monitoring
R5
Figure 20. Temperature Controller
REF02
U2
GND
V
IN
TEMP
2
4
OP1177
V
15V
O
V+
V–
3
6
V
(9.2kΩ)
(1.3kΩ)
IN
R1
R3
1.5kΩ
2.7kΩ
V
TEMP
IN
R2
R4
REF02
R6
GND
U1
SY
2
3
V
TRIM
) of the 15.000 V
OUT
+
CMP02
–
1
V+
8
V–
V
4
O
7
R7
27kΩ
Rev. F | Page 11 of 16
PRECISION CURRENT SOURCE
A current source with 35 V output compliance and excellent
output impedance can be obtained using this circuit. REF02
keeps the line voltage and power dissipation constant in device;
the only important error consideration at room temperature is
the negative supply rejection of the op amp. The typical 3 µV/V
PSRR of the OP02E will create a 20 ppm change (3 µV/V ×
35 V/5 V) in output current over a 25 V range. For example, a
5 mA current source can be built (R = 1 kΩ) with 350 MΩ
output impedance.
27V TO 55V
REF02
REF02
GND
REF02
R
GND
V
V
O
GND
IN
IN
V
2
TRIM
4
2
4
1
=
TRIM
IN
2
4
20
V
V
O
O
V
×
O
10
6
5
5
6
35V
–6
6
Figure 22. Precision Current Source
×
5mA
Figure 21. Reference Stack
R
C
6
6
V
O
REF02
OP02E
+50V
GND
4
–5V
REF02
V
2
IN
GND
V
2
7
4
IN
TRIM
2
4
10kΩ
V
2
3
O
5
6
C
R
(TRIM FOR
CALIBRATION)
I
O
=
5V
10kΩ
V
R
10kΩ
TO 25V
R
6.8kΩ
O
B
10V
15V
= 0V
REF02
5V