a
FUNCTIONAL BLOCK DIAGRAM
CS
16
UNI/
BIP CLR
17
OR LBE
HBE 18
Data can be loaded into the AD760 as straight binary, serial
data or as two 8-bit bytes. In serial mode, 16-bit or 18-bit data
can be used and the serial mode input format is pin selectable,
to be MSB or LSB first. This is made possible by three digital
input pins which have dual functions (Pins 12, 13, and 14). In
byte mode the user can similarly define whether the high byte or
low byte is loaded first. The serial output (SOUT) pin allows the
user to daisy chain several AD760s by shifting the data through
the input latch into the next DAC thus minimizing the number
of control lines required in a multiple DAC application. The
double buffered latch structure eliminates data skew errors and
provides for simultaneous updating of DACs in a multi-DAC
system.
The asynchronous CLR function can be configured to clear the
output to minus full-scale or midscale depending on the state of
Pin 17 when CLR is strobed. The AD760 also powers up with the
REV. A
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.
7
AD760
16/18-BIT
INPUT REGISTER
15
SOUT
24
SPAN/
BIP
OFF
23
VOUT
27
MUXOUT
28
SER 19
MUX I N
22
AGND
10k
16/18-BIT DAC LATCH
CLR 20
10k
LDAC 21
REF IN 25
MAIN DAC
9.95k
RAM
+10V
REF
REF OUT 26
CALIBRATION DAC
CALIBRATION SEQUENCER
1
2
3
4
5
6
CALOK
CAL
–VEE
+VCC
+VLL
DGND
MUX output in a predetermined state by means of a digital and
analog power supply detection circuit. This is particularly useful for robotic and industrial control applications.
The AD760 is available in a 28-pin, 600 mil cerdip package.
The AQ version is specified from –40°C to +85°C.
RELATIVE ACCURACY – LSB
Self-calibration is initiated by simply pulsing the CAL pin low.
The CALOK pin indicates when calibration has been successfully completed. The output multiplexer (MUXOUT) can be used
to send the output to the bottom of the output range during
calibration.
DB7
12
13
14
PRODUCT DESCRIPTION
The AD760 is a complete 16/18-bit self-calibrating monolithic
DAC (DACPORT®) with onboard voltage reference, double
buffered latches and output amplifier. It is manufactured on
Analog Devices’ BiMOS II process. This process allows the fabrication of low power CMOS logic functions on the same chip
as high precision bipolar linear circuitry.
MSB/ 18/16
SIN LSB SERIAL
OR OR OR
DB0 DB1 DB2
CONTROL
LOGIC
FEATURES
±0.2 LSB (±0.00031%) Typ Peak DNL and INL
±0.5 LSB (±0.00076%) Typ Unipolar Offset, Bipolar Zero
17-Bit Monotonicity Guaranteed
18-Bit Resolution (in Serial Mode)
Complete 16/18-Bit D/A Function
On-Chip Output Amplifier
On-Chip Buried Zener Voltage Reference
Microprocessor Compatible
Serial or Byte Input
Double Buffered Latches
Asynchronous Clear Function
Serial Output Pin Facilitates Daisy Chaining
Pin Strappable Unipolar or Bipolar Output
Low THD+N: 0.005%
MUX Output Control on Power-Up and Supply Glitches
16/18-Bit Self-Calibrating
Serial/Byte DACPORT
AD760
VOUT = –10V TO +10V
RL = 2kΩ
CL = 1000pF
0.75
0.25
0
–0.25
–0.75
0
16384
32768
49152
65535
INPUT CODE – Decimal
Typical Integral Nonlinearity
DACPORT is a registered trademark of Analog Devices, Inc.
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
