AD780BNZ Analog Devices Inc, AD780BNZ Datasheet - Page 5
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AD780BNZ
Manufacturer Part Number
AD780BNZ
Description
IC PREC V-REF 2.5V/3.0V 8-DIP
Manufacturer
Analog Devices Inc
Type
Voltage Referencer
Specifications of AD780BNZ
Temperature Coefficient
3ppm/°C
Operating Temperature
-40°C ~ 85°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
Mounting Type
Through Hole
Package / Case
8-DIP (0.300", 7.62mm)
Topology
Series
Input Voltage
4V To 36V
Reference Voltage
2.5V
Reference Voltage Tolerance
1mV
Voltage Reference Case Style
DIP
No. Of Pins
8
Current, Output
0 to 10 mA
Current, Supply
0.75 mA
Package Type
PDIP-8
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
RoHS Compliant part
Electrostatic Device
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD780BNZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
THEORY OF OPERATION
Band gap references are the high performance solution for low
supply voltage and low power voltage reference applications. In
this technique, a voltage with a positive temperature coefficient
is combined with the negative coefficient of a transistor’s V
produce a constant band gap voltage.
In the AD780, the band gap cell contains two NPN transistors
(Q6 and Q7) that differ in emitter area by 12×. The difference in
their V
produces a PTAT voltage across R4 that, when combined with
the V
temperature. Precision laser trimming of the resistors and other
patented circuit techniques are used to further enhance the drift
performance.
be
be
TEMP
of Q7, produces a voltage (V
s produces a PTAT current in R5. This, in turn,
NC = NO CONNECT
NC
1
3
AD780
R10
Q6
Figure 4. Schematic Diagram
+V
2
R5
R4
IN
R11
GND
Q7
4
bg
R14
) that does not vary with
NC
O/P SELECT
2.5V – NC
3.0V – GND
7
8
R13
R15
R16
6
5
V
TRIM
OUT
be
to
Rev. E | Page 5 of 12
The output voltage of the AD780 is determined by the
configuration of Resistors R13, R14, and R15 in the amplifier’s
feedback loop. This sets the output to either 2.5 V or 3.0 V,
depending on whether R15 (Pin 8) is grounded or not
connected.
A unique feature of the AD780 is the low headroom design of
the high gain amplifier, which produces a precision 3 V output
from an input voltage as low as 4.5 V (or 2.5 V from a 4.0 V
input). The amplifier design also allows the part to work with
+V
This allows the AD780 to work as a 2-terminal shunt regulator,
providing a −2.5 V or −3.0 V reference voltage output without
external components.
The PTAT voltage is also used to provide the user with a
thermometer output voltage (at Pin 3) that increases at a rate of
approximately 2 mV/°C.
The AD780’s NC (Pin 7) is a 20 kΩ resistor to +V
solely for production test purposes. Users who are currently
using the LT1019 self-heater pin (Pin 7) must take into account
the different load on the heater supply.
IN
= V
OUT
when current is forced into the output terminal.
IN
that is used
AD780