ADR3430ARJZ-R2 Analog Devices Inc, ADR3430ARJZ-R2 Datasheet - Page 21

• Manufacturer Part Number: ADR3430ARJZ-R2
• Description: IC VOLTAGE REF 3.3V SOT23-6
• Manufacturer: Analog Devices Inc

Specifications of ADR3430ARJZ-R2

• Topology: Series
• Input Voltage: 2.7V To 5.5V
• Reference Voltage: 3V
• Reference Voltage Tolerance: 3mV
• Voltage Reference Case Style: SOT-23
• No. Of Pins: 6
• Temperature Coefficient: 2.5ppm/°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ADR3430ARJZ-R2; ADR3430ARJZ-R2TR

SAMPLE APPLICATIONS
Negative Reference
Figure 42 shows how to connect the ADR3450 and a standard
CMOS op amp, such as the AD8663, to provide a negative
reference voltage. This configuration provides two main
advantages: first, it only requires two devices and, therefore,
does not require excessive board space; second, and more
importantly, it does not require any external resistors, meaning
that the performance of this circuit does not rely on choosing
expensive parts with low temperature coefficients to ensure
accuracy.
+VDD
In this configuration, the V
ground, and the negative reference voltage and load current are
taken directly from the output of the operational amplifier. Note
that in applications where the negative supply voltage is close to
the reference output voltage, a dual-supply, low offset, rail-to-
rail output amplifier must be used to ensure an accurate output
voltage. The operational amplifier must also be able to source or
sink an appropriate amount of current for the application.
Bipolar Output Reference
Figure 43 shows a bipolar reference configuration. By connecting
the output of the ADR3450 to the inverting terminal of an
operational amplifier, it is possible to obtain both positive and
negative reference voltages. R1 and R2 must be matched as
closely as possible to ensure minimal difference between the
negative and positive outputs. Resistors with low temperature
coefficients must also be used if the circuit is used in environments
with large temperature swings; otherwise, a voltage difference
develops between the two outputs as the ambient temperature
changes.
1µF
0.1µF
Figure 42. ADR3450 Negative Reference
4
3
V
ENABLE
IN
ADR3450
V
V
GND FORCE
GND SENSE
OUT
OUT
OUT
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
pins of the reference sit at virtual
FORCE
SENSE
6
5
2
1
0.1µF
–VDD
AD8663
0.1µF
–5V
Rev. B | Page 21 of 24
Boosted Output Current Reference
Figure 44 shows a configuration for obtaining higher current
drive capability from the ADR34xx references without
sacrificing accuracy. The op amp regulates the current flow
through the MOSFET until V
the reference; current is then drawn directly from V
from the reference itself, allowing increased current drive
capability.
Because the current-sourcing capability of this circuit depends
only on the I
can be adjusted to the application simply by choosing an
appropriate MOSFET. In all cases, the V
be tied directly to the load device to maintain maximum output
voltage accuracy.
V
1µF
IN
1µF
0.1µF
4
3
V
ENABLE
0.1µF
IN
D
Figure 43. ADR3450 Bipolar Output Reference
Figure 44. Boosted Output Current Reference
rating of the MOSFET, the output drive capability
ADR34xx
4
3
V
ENABLE
U6
V
V
GND FORCE
GND SENSE
IN
OUT
OUT
ADR3450
FORCE
SENSE
V
V
GND FORCE
GND SENSE
OUT
OUT
V
OUT
6
5
2
1
IN
FORCE
0.1µF
SENSE
equals the output voltage of
6
5
2
1
+16V
0.1µF
OUT
ADA4000-1
AD8663
100Ω
R1
SENSE pin should
5kΩ
R3
R1
10kΩ
2N7002
200Ω
10kΩ
R2
IN
+15V
–15V
R
L
instead of
V
C
0.1µF
OUT
+5V
–5V
L