2
LC MOS
12-Bit DACPORTs
a
AD7245A/AD7248A
FEATURES
AD 7245A FUNCTIO NAL BLO CK D IAGRAM
12-Bit CMOS DAC w ith Output Am plifier and
Reference
Im proved AD7245/ AD7248:
12 V to 15 V Operation
؎1/ 2 LSB Linearity Grade
Faster Interface–30 ns typ Data Setup Tim e
Extended Plastic Tem perature Range (–40؇C to +85؇C)
Single or Dual Supply Operation
Low Pow er–65 m W typ in Single Supply
Parallel Loading Structure: AD7245A
(8+4) Loading Structure: AD7248A
GENERAL D ESCRIP TIO N
T he AD7245A/AD7248A is an enhanced version of the industry
standard AD7245/AD7248. Improvements include operation
from 12 V to 15 V supplies, a ±1/2 LSB linearity grade, faster
interface times and better full scale and reference variations with
AD 7248A FUNCTIO NAL BLO CK D IAGRAM
VDD. Additional features include extended temperature range
operation for commercial and industrial grades.
T he AD7245A/AD7248A is a complete, 12-bit, voltage output,
digital-to-analog converter with output amplifier and Zener volt-
age reference on a monolithic CMOS chip. No external user
trims are required to achieve full specified performance.
Both parts are microprocessor compatible, with high speed data
latches and double-buffered interface logic. T he AD7245A ac-
cepts 12-bit parallel data which is loaded into the input latch on
the rising edge of CS or WR. T he AD7248A has an 8-bit wide
data bus with data loaded to the input latch in two write opera-
tions. For both parts, an asynchronous LDAC signal transfers
data from the input latch to the DAC latch and updates the ana-
log output. T he AD7245A also has a CLR signal on the DAC latch
which allows features such as power-on reset to be implemented.
T he on-chip 5 V buried Zener diode provides a low noise, tem-
perature compensated reference for the DAC. For single supply
operation, two output ranges of 0 V to +5 V and 0 V to +10 V
are available, while these two ranges plus an additional ±5 V
range are available with dual supplies. T he output amplifiers are
capable of developing +10 V across a 2 kΩ load to GND.
SOIC and in 28-terminal surface mount packages. T he
AD7248A is packaged in a small, 0.3" wide, 20-pin DIP and
SOIC and in 20-terminal surface mount packages.
P RO D UCT H IGH LIGH TS
1. T he AD7245A/AD7248A is a 12-bit DACPORT® on a single
chip. T his single chip design and small package size offer
considerable space saving and increased reliability over
multichip designs.
T he AD7245A/AD7248A is fabricated in linear compatible
CMOS (LC2MOS), an advanced, mixed technology process that
combines precision bipolar circuits with low power CMOS logic.
T he AD7245A is available in a small, 0.3" wide, 24-pin DIP and
2. T he improved interface times on the part allows easy, direct
interfacing to most modern microprocessors.
3. T he AD7245A/AD7248A features a wide power supply range
allowing operation from 12 V supplies.
D ACP O RT is a r egister ed tr adem ar k of Analog D evices, Inc.
REV. A
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
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