ADR3430ARJZ-R7 Analog Devices Inc, ADR3430ARJZ-R7 Datasheet - Page 19

• Manufacturer Part Number: ADR3430ARJZ-R7
• Description: IC VOLTAGE REF 3.3V SOT23-6
• Manufacturer: Analog Devices Inc

Specifications of ADR3430ARJZ-R7

• Topology: Series
• Input Voltage: 3.2V 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

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THEORY OF OPERATION
The ADR3412/ADR3425/ADR3430/ADR3433/ADR3440/
ADR3450 use a patented voltage reference architecture to
achieve high accuracy, low temperature coefficient (TC), and
low noise in a CMOS process. Like all band gap references, the
references combine two voltages of opposite TCs to create an
output voltage that is nearly independent of ambient temper-
ature. However, unlike traditional band gap voltage references, the
temperature-independent voltage of the references are arranged
to be the base-emitter voltage, V
room temperature rather than the V
V
gap voltage of silicon). A corresponding positive-TC voltage is
then added to the V
The key benefit of this technique is that the trimming of the
initial accuracy and TC can be performed without interfering
with one another, thereby increasing overall accuracy across
temperature. Curvature correction techniques further reduce
the temperature variation.
The band gap voltage (V
produce stable output voltages of 2.5 V and 5.0 V. The output
buffer can source up to 10 mA and sink up to −3 mA of load
current.
The ADR34xx family leverages Analog Devices patented
DigiTrim technology to achieve high initial accuracy and low
TC, and precision layout techniques lead to very low long-term
drift and thermal hysteresis.
BE
of bipolar transistor at 0 K is approximately V
REFERENCE
BAND GAP
VOLTAGE
BE
Figure 39. Block Diagram
voltage to compensate for its negative TC.
BG
V
BG
) is then buffered and amplified to
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
BE
GND SENSE
, of a bipolar transistor at
V
GND FORCE
BE
IN
extrapolated to 0 K (the
R
R
FB1
FB2
G0
, the band
V
V
OUT
OUT
FORCE
SENSE
Rev. B | Page 19 of 24
LONG-TERM STABILITY
One of the key parameters of the ADR34xx references is long-
term stability. Regardless of output voltage, internal testing
during development showed a typical drift of approximately
30 ppm after 1000 hours of continuous, nonloaded operation
in a 50°C environment.
It is important to understand that long-term stability is not
guaranteed by design and that the output from the device may
shift beyond the typical 30 ppm specification at any time,
especially during the first 200 hours of operation. For systems
that require highly stable output voltages over long periods of
time, the designer should consider burning in the devices prior
to use to minimize the amount of output drift exhibited by the
reference over time. See the AN-713 Application Note, The
Effect of Long-Term Drift on Voltage References, at
for more information regarding the effects of long-term drift
and how it can be minimized.
POWER DISSIPATION
The ADR34xx voltage references are capable of sourcing up to
10 mA of load current at room temperature across the rated
input voltage range. However, when used in applications subject
to high ambient temperatures, the input voltage and load cur-
rent should be carefully monitored to ensure that the device
does not exceeded its maximum power dissipation rating. The
maximum power dissipation of the device can be calculated via
the following equation:
where:
P
T
T
θ
Because of this relationship, acceptable load current in high
temperature conditions may be less than the maximum current-
sourcing capability of the device. In no case should the part be
operated outside of its maximum power rating because doing so
can result in premature failure or permanent damage to the device.
JA
D
J
A
is the device junction temperature.
is the device power dissipation.
is the ambient temperature.
is the package (junction-to-air) thermal resistance.
P
D
=
T
J
θ
−
JA
T
A
[W
]
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