CONNECTION DIAGRAMS
1
2
3
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8
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5
TOP VIEW
(Not to Scale)
AD680
TP*
+V
IN
TEMP
GND
TP*
TP*
V
OUT
NC
NC = NO CONNECT
TP DENOTES FACTORY TEST POINT.
NO CONNECTIONS SHOULD BE MADE
TO THESE PINS.
*
3 2 1
+V
IN
V
OUT
GND
AD680
BOTTOM VIEW
(Not to Scale)
REV. C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
Low Power, Low Cost
2.5 V Reference
AD680*
FEATURES
Low Quiescent Current: 250 mA max
Laser Trimmed to High Accuracy:
2.5 V 65 mV max (AN, AR Grade)
Trimmed Temperature Coefficient:
20 ppm/8C max (AN, AR Grade)
Low Noise: 8 mV p-p from 0.1 Hz to 10 Hz
250 nV/√
Hz Wideband
Temperature Output Pin (N, R Packages)
Available in Three Package Styles:
8-Pin Plastic DIP, 8-Pin SOIC and 3-Pin TO-92
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
PRODUCT DESCRIPTION
The AD680 is a bandgap voltage reference which provides a
fixed 2.5 V output from inputs between 4.5 V and 36 V. The
architecture of the AD680 enables the reference to be operated
at a very low quiescent current while still realizing excellent dc
characteristics and noise performance. Trimming of the high
stability thin-film resistors is performed for initial accuracy and
temperature coefficient, resulting in low errors over temperature.
The precision dc characteristics of the AD680 make it ideal for
use as a reference for D/A converters which require an external
precision reference. The device is also ideal for A/D converters
and, in general, can offer better performance than the standard
on-chip references.
Based upon the low quiescent current of the AD680, which
rivals that of many incomplete two-terminal references, the
AD680 is recommended for low power applications such as
hand-held battery equipment.
A temperature output pin is provided on the 8-pin package ver-
sions of the AD680. The temperature output pin provides an
output voltage that varies linearly with temperature and allows
the AD680 to be configured as a temperature transducer while
providing a stable 2.5 V output.
The AD680 is available in five grades. The AD680AN is speci-
fied for operation from –40°C to +85°C, while the AD680JN
is specified for 0°C to +70°C operation. Both the AD680AN
and AD680JN are available in 8-pin plastic DIP packages. The
AD680AR is specified for operation from –40°C to +85°C,
while the AD680JR is specified for 0°C to +70°C operation.
Both are available in an 8-pin Small Outline IC (SOIC) pack-
age. The AD680JT is specified for 0°C to +70°C operation and
is available in a 3-pin TO-92 package.
*Protected by U.S. Patent Nos. 4,902,959; 4,250,445 and 4,857,862.
PRODUCT HIGHLIGHTS
1. The AD680 bandgap reference operates on a very low quies-
cent current which rivals that of many two-terminal refer-
ences. This makes the complete, higher accuracy AD680
ideal for use in power sensitive applications.
2. Laser trimming of both initial accuracy and temperature
coefficients results in low errors over temperature without the
use of external components. The AD680AN and AD680AR
have a maximum variation of 6.25 mV between –40°C and
+85°C.
3. The AD680 noise is low, typically 8 µV p-p from 0.1 Hz to
10 Hz. Spectral density is also low, typically 250 nV/√
Hz.
4. The temperature output pin on the 8-pin package versions
enables the AD680 to be configured as a temperature trans-
ducer.
5. Plastic DIP packaging provides machine insertability, while
SOIC packaging provides surface mount capability. TO-92
packaging offers a cost effective alternative to two-terminal
references, offering a complete solution in the same package
in which two-terminal references are usually found.
