Complete 16-Bit D/A Function
On-Chip Output Amplifier
On-Chip Buried Zener Voltage Reference
؎1 LSB Integral Linearity
15-Bit Monotonic over Temperature
Serial or Byte Input
Double Buffered Latches
Fast (40 ns) Write Pulse
Asynchronous Clear (to 0 V) Function
Serial Output Pin Facilitates Daisy Chaining
Unipolar or Bipolar Output
Low Glitch: 15 nV-s
Low THD+N: 0.009%
FUNCTIONAL BLOCK DIAGRAM
DB0 DB1 DB7
REF IN 23
24 1 2
REF OUT –VEE +VCC
The AD660 DACPORT® is a complete 16-bit monolithic D/A
converter with an on-board voltage reference, double buffered
latches and output amplifier. It is manufactured on Analog De-
vices’ BiMOS II process. This process allows the fabrication of
low power CMOS logic functions on the same chip as high pre-
cision bipolar linear circuitry.
The AD660’s architecture ensures 15-bit monotonicity over
time and temperature. Integral and differential nonlinearity is
maintained at ± 0.003% max. The on-chip output amplifier pro-
vides a voltage output settling time of 10 µs to within 1/2 LSB
for a full-scale step.
The AD660 has an extremely flexible digital interface. Data can
be loaded into the AD660 in serial mode or as two 8-bit bytes.
This is made possible by two digital input pins which have dual
functions. The serial mode input format is pin selectable to be
MSB or LSB first. The serial output pin allows the user to daisy
chain several AD660s by shifting the data through the input
latch into the next DAC thus minimizing the number of control
lines required to SIN, CS and LDAC. The byte mode input for-
mat is also flexible in that the high byte or low byte data can be
loaded first. The double buffered latch structure eliminates data
skew errors and provides for simultaneous updating of DACs in
a multi-DAC system.
The AD660 is available in five grades. AN and BN versions are
specified from –40°C to +85°C and are packaged in a 24-pin
300 mil plastic DIP. AR and BR versions are also specified from
–40°C to +85°C and are packaged in a 24-pin SOIC. The SQ
version is packaged in a 24-pin 300 mil cerdip package and is
also available compliant to MIL-STD-883. Refer to the AD660/
883B data sheet for specifications and test conditions.
1. The AD660 is a complete 16-bit DAC, with a voltage refer-
ence, double buffered latches and output amplifier on a sin-
2. The internal buried Zener reference is laser trimmed to
10.000 volts with a ± 0.1% maximum error and a tempera-
ture drift performance of ± 15 ppm/°C. The reference is
available for external applications.
3. The output range of the AD660 is pin programmable and can
be set to provide a unipolar output range of 0 V to +10 V or
a bipolar output range of –10 V to +10 V. No external com-
ponents are required.
4. The AD660 is both dc and ac specified. DC specifications
include ± 1 LSB INL and ± 1 LSB DNL errors. AC specifi-
cations include 0.009% THD+N and 83 dB SNR.
5. The double buffered latches on the AD660 eliminate data
skew errors and allow simultaneous updating of DACs in
6. The CLEAR function can asynchronously set the output to
0 V regardless of whether the DAC is in unipolar or bipolar
7. The output amplifier settles within 10 µs to ± 1/2 LSB for a
full-scale step and within 2.5 µs for a 1 LSB step over tem-
perature. The output glitch is typically 15 nV-s when a full-
scale step is loaded.
DACPORT is a registered trademark of Analog Devices, Inc.
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.
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