AD780BRZ Analog Devices Inc, AD780BRZ Datasheet - Page 10

• Manufacturer Part Number: AD780BRZ
• Description: IC PREC V-REF 2.5V/3.0V 8-SOIC
• Manufacturer: Analog Devices Inc
• Type: Voltage Referencer

Specifications of AD780BRZ

• Temperature Coefficient: 3ppm/°C
• Design Resources: Using AD8599 as an Ultralow Distortion Driver for the AD7991 (CN0043) Using AD8599 as an Ultralow Distortion Driver for the AD7995 (CN0044) Using AD8599 as an Ultralow Distortion Driver for the AD7999 (CN0045) Using AD7328 in Appls with Single-Ended Industrial-Level Signals (CN0047) AD5382 Channel Monitor Function (CN0012) AD5383 Channel Monitor Function (CN0015) AD5390/91/92 Channel Monitor Function (CN0030) Measuring -48 V High-Side Current Using AD629, AD8603, AD780, and AD7453 (CN0100) High Voltage, High Precision Current Sensing with Output Level Shifting Using AD8210 and AD8274 (CN0116)
• Reference Type: Series and Shunt, Programmable
• Voltage - Output: 2.5V, 3V
• Tolerance: ±1mV
• Voltage - Input: 4 ~ 36 V
• Number Of Channels: 1
• Current - Quiescent: 1mA
• Current - Output: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Topology: Series
• Input Voltage: 4V To 36V
• Reference Voltage: 2.5V
• Reference Voltage Tolerance: 1mV
• Voltage Reference Case Style: SOIC
• No. Of Pins: 8
• Fixed / Adjust / Prog: Programmable
• Output Voltage (max): 2.5/3V
• Reference Voltage Accuracy (max): 1
• Line Regulation: 10uV/V
• Load Regulation: 75uV/mA
• Input Voltage (max): 36V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC N
• Current, Output: 0 to 10 mA
• Current, Supply: 0.75 mA
• Power Dissipation: 500 mW
• Regulation, Line: 10 μV/V
• Regulation, Load: 75 μV/mA
• Regulator Type: Negative Voltage Out, Series/Shunt
• Temperature, Operating, Range: -40 to +85 °C
• Voltage, Input: 5 V
• Voltage, Noise: 4 μVp-p
• Voltage, Output: 2.501 or 3.001 V
• Voltage, Supply: 4.5 to 5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Cathode: -
• Lead Free Status / Rohs Status: Compliant

AD780
The AD780 is also ideal for use with higher resolution
converters, such as the AD7710/AD7711/AD7712 (see Figure
22. While these parts are specified with a 2.5 V internal
reference, the AD780 in 3 V mode can be used to improve the
absolute accuracy, temperature stability, and dynamic range. It is
shown in Figure 22 with the two optional noise reduction
capacitors.
4.5 V REFERENCE FROM 5 V SUPPLY
Some 5 V high resolution ADCs can accommodate reference
voltages up to 4.5 V. The AD780 can be used to provide a
precision 4.5 V reference voltage from a 5 V supply using the
circuit shown in Figure 23. This circuit provides a regulated
4.5 V output from a supply voltage as low as 4.7 V. The high
quality tantalum 10 µF capacitor, in parallel with the ceramic
AD780 0.1 µF capacitor and the 3.9 Ω resistor, ensures a low
output impedance around 50 MHz.
Figure 21. Precision 3 V Reference for the AD7884 16-Bit, High Speed ADC
100nF
1µF
1µF
Figure 22. Precision 2.5 V or 3.0 V Reference for the
AD7710 High Resolution, Σ-∆ ADC
3
GND
GND
4
4
AD780
AD780
+V
+V
5V
5V
O/P SELECT
2
2
2.5V/3.0V
IN
IN
SELECT
2.5V/3.0V
V
OUT
8
8
V
OUT
6
6
100µF
V
V
AD7884
REF
REF
AD7710
+ F
+ S
REF IN+
REF IN–
Rev. E | Page 10 of 12
NEGATIVE (–2.5 V) REFERENCE
The AD780 can produce a negative output voltage in shunt
mode by connecting the input and output to ground, and
connecting the AD780’s GND pin to a negative supply via a bias
resistor, as shown in Figure 25.
A precise –2.5 V reference capable of supplying up to 100 mA to
a load can be implemented with the AD780 in series mode,
using the bootstrap circuit shown in Figure 25.
AD780
2
4
0.01%
R =
1µF
Figure 24. Negative (−2.5 V Shunt Mode Reference)
5kΩ
Figure 23. 4.5 V Reference from a Single 5 V Supply
+
–
6
1kΩ
OP07
Figure 25. −2.5 V High Load Current Reference
V
I
L
OUT
+5V
–5V
+ I
V
S
0.1µF
– (V–)
SUPPLY
3
2
1
3
MIN
+
OP90
–
NC
TEMP
+V
OUT
GND
2
IN
V–
0.01%
0.1µF
4
7
4
4kΩ
1kΩ
AD780
6
1000pF
NOTES
1. I
2. I
3. NC = NO CONNECT
O/P SELECT
AD780
3.0V – GND
2.5V – NC
L
S
6
–5V
+5V
= LOAD CURRENT
MIN = MINIMUM SHUNT CURRENT
4
2
2N3906
+V
8
V
TRIM
NC
OUT
IN
7
8
2.5kΩ
6
5
CONNECT IF
–3V OUTPUT
DESIRED
2N2907
–2.5V (I
10µF
–2.5 V
3.9Ω
OUT
L
≤
100mA)
0.1µF
V
OUT