ADR510 Analog Devices, ADR510 Datasheet - Page 5

• Manufacturer Part Number: ADR510
• Description: 1.0 V Precision Low Noise Shunt Voltage Reference
• Manufacturer: Analog Devices

Adjustable Precision Voltage Source
The ADR510, combined with a precision low input bias op amp
such as the AD8610, can be used to output a precise adjustable
voltage. Figure 2 illustrates the implementation of this application
using the ADR510.
The output of the op amp, V
circuit, which is completely dependent on Resistors R2 and R1.
An additional capacitor in parallel with R2 can be added to filter
out high frequency noise. The value of C2 is dependent on the
value of R2.
Output Voltage Trim
Using a mechanical or digital potentiometer, the output voltage
of the ADR510 can be trimmed ± 0.5%. The circuit in Figure 3
illustrates how the output voltage can be trimmed, using a 10 kΩ
potentiometer. Note that trimming using other resistor values
may not produce an accurate output from the ADR510.
Using the ADR510 with Precision Data Converters
The compact ADR510 and its low minimum operating current
requirement make it ideal for use in battery-powered portable
instruments, such as the AD7533 CMOS multiplying DAC, that
use precision data converters.
REV. 0
V
Figure 2. Adjustable Precision Voltage Source
OUT
ADR510
= +
1
R
ADR510
BIAS
Figure 3. Output Voltage Trim
R2
V
R1
CC
R
1.0V
BIAS
R1
V
CC
AD8610
C2 (OPTIONAL)
OUT
R2
470k
, is determined by the gain of the
R1
V
OUT
POT
10k
= (1 + R2/R1)
V
OUT
(4)
–5–
Figure 4 shows the ADR510 serving as an external reference to
the AD7533, a CMOS multiplying DAC. Such a DAC requires
a negative voltage input in order to provide a positive output range.
In this application, the ADR510 is supplying a –1.0 V reference
to the REF input of the AD7533.
Precise Negative Voltage Reference
The ADR510 is suitable for use in applications where a precise
negative voltage reference is desired, including the application
detailed in Figure 4.
Figures 5 shows the ADR510 configured to provide a –1.0 V output.
Since the ADR510 characteristics resemble those of a Zener
diode, the cathode shown in Figure 5 will be 1.0 V higher with
respect to the anode (V+ with respect to V– on the ADR510
package). Since the cathode of the ADR510 is tied to ground,
the anode must be –1.0 V.
R1 in Figure 5 should be chosen so that 100 µA to 10 mA is
provided to properly bias the ADR510.
The R1 resistor should be chosen so that power dissipation is at
a minimum. An ideal resistor value can be determined through
manipulation of Equation 5.
R
Figure 5. Precise –1.0 V Reference Configuration
ADR510
1 =
Figure 4. ADR510 as a Reference for a 10-Bit
CMOS DAC (AD7533)
V
DD
I
R2
–V
DD
V
DD
ADR510
MSB
G
N
0
1
1
3
R1
2
–V
DD
1
AD7533
–1.0V
15
9
LSB
V
OUT
ADR510
= 0V TO 1.0V
(5)