ADR431ARMZ Analog Devices Inc, ADR431ARMZ Datasheet - Page 18

• Manufacturer Part Number: ADR431ARMZ
• Description: IC VOLT REF XFET 2.5V 8-MSOP
• Manufacturer: Analog Devices Inc
• Series: XFET®r

Specifications of ADR431ARMZ

• Temperature Coefficient: 10ppm/°C
• Design Resources: 40 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5380 (CN0007) 40 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5381 (CN0010) 32 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5382 (CN0011) 32 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5383 (CN0014) 8 to 16 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5390/1/2 (CN0029) AD5390/91/92 Channel Monitor Function (CN0030) 16 Channels of Programmable Output Span Using AD5360 (CN0131) 40 Channels of Programmable Output Span Using AD5371 (CN0149)
• Reference Type: Series
• Voltage - Output: 2.5V
• Tolerance: ±0.12%
• Voltage - Input: 4.5 ~ 18 V
• Number Of Channels: 1
• Current - Quiescent: 800µA
• Current - Output: 30mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Topology: Series
• Input Voltage: 4.5V To 18V
• Reference Voltage: 2.5V
• Reference Voltage Tolerance: 3mV
• Voltage Reference Case Style: MSOP
• No. Of Pins: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Cathode: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

ADR430/ADR431/ADR433/ADR434/ADR435/ADR439
A negative reference can easily be generated by adding a
precision operational amplifier, such as the
OP193, and configuring it as shown in Figure 36. V
virtual ground; therefore, the negative reference can be taken
directly from the output of the amplifier. The operational
amplifier must be dual supply and have low offset and rail-
to-rail capability if the negative supply voltage is close to the
reference output.
HIGH VOLTAGE FLOATING CURRENT SOURCE
The circuit in Figure 37 can be used to generate a floating
current source with minimal self heating. This particular
configuration can operate on high supply voltages determined
by the breakdown voltage of the N-channel JFET.
KELVIN CONNECTION
In many portable instrumentation applications, where printed
circuit board (PCB) cost and area go hand in hand, circuit
interconnects are very often of dimensionally minimum width.
These narrow lines can cause large voltage drops if the voltage
reference is required to provide load currents to various functions.
In fact, circuit interconnects can exhibit a typical line resistance
of 0.45 mΩ/square (for example, 1 oz. Cu). Force and sense
connections, also referred to as Kelvin connections, offer a
convenient method of eliminating the effects of voltage drops
in circuit wires. Load currents flowing through wiring resistance
produce an error (V
Kelvin connection of Figure 38 overcomes the problem by
including the wiring resistance within the forcing loop of the
operational amplifier.
Figure 37. High Voltage Floating Current Source
ADR43x
GND
–V
V
4
A1
2
V
IN
DD
OUT
Figure 36. Negative Reference
ERROR
6
= R × I
6
V
OP90
OUT
ADR43x
+V
GND
V
L
2
4
DD
IN
) at the load. However, the
+V
S
–V
OP777
2N3904
–V
VISHAY
SST111
S
R
2.1kΩ
REF
L
or the
OUT
is at
Rev. H | Page 18 of 24
Because the amplifier senses the load voltage, the operational
amplifier loop control forces the output to compensate for the
wiring error and to produce the correct voltage at the load.
DUAL POLARITY REFERENCES
Dual polarity references can easily be made with an operational
amplifier and a pair of resistors. To avoid defeating the accuracy
obtained by the ADR43x, it is imperative to match the resistance
tolerance as well as the temperature coefficient of all the components.
V
IN
1µF
+10V
Figure 40. +2.5 V and −2.5 V References Using ADR435
Figure 39. +5 V and −5 V References Using ADR435
ADR43x
Figure 38. Advantage of Kelvin Connection
0.1µF
GND
V
2
4
GND
IN
V
V
2
IN
4
OUT
ADR435
GND
V
2
4
U1
6
ADR435
IN
TRIM
V
U1
OUT
V
TRIM
OP191
+

OUT
A1
6
5
DOCPROPERTY "ADI
V
5.6kΩ
5.6kΩ
IN
6
5
R
R1
R2
+2.5V
–2.5V
LW
10kΩ
5kΩ
R3
R
R1
LW
OP1177
OP1177
+10V
– 10V
V+
V
SENSE
V
FORCE
R
V–
U2
–10V
U2
OUT
OUT
L
V+
V–
10kΩ
R2
P li "
+5V
–5V