DACPORT Low Cost, Complete
a
µP-Compatible 8-Bit DAC
AD558*
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Complete 8-Bit DAC
CONTROL
INPUTS
DIGITAL INPUT DATA (BUS)
Voltage Output–2 Calibrated Ranges
Internal Precision Bandgap Reference
Single-Supply Operation: +5 V to +15 V
Full Microprocessor Interface
Fast: 1 s Voltage Settling to ؎1/2 LSB
Low Power: 75 mW
MSB
+V
LSB
LSB
CC
GND CS CE
2
I L
2
I L LATCHES
CONTROL
LOGIC
MSB
No User Trims
OUTPUT
AMP
Guaranteed Monotonic Over Temperature
All Errors Specified TMIN to TMAX
Small 16-Pin DIP and 20-Pin PLCC Packages
Single Laser-Wafer-Trimmed Chip for Hybrids
Low Cost
8-BIT VOLTAGE-SWITCHING
D-TO-A CONVERTER
V
V
OUT
CONTROL
AMP
SENSE A
OUT
BAND -
GAP
REFERENCE
V
SELECT
OUT
MIL-STD-883 Compliant Versions Available
AD558
GND
PRODUCT DESCRIPTION
PRODUCT HIGHLIGHTS
1. The 8-bit I2L input register and fully microprocessor-
compatible control logic allow the AD558 to be directly
connected to 8- or 16-bit data buses and operated with
standard control signals. The latch may be disabled for
direct DAC interfacing.
The AD558 DACPORT® is a complete voltage-output 8-bit
digital-to-analog converter, including output amplifier, full
microprocessor interface and precision voltage reference on a
single monolithic chip. No external components or trims are
required to interface, with full accuracy, an 8-bit data bus to an
analog system.
2. The laser-trimmed on-chip SiCr thin-film resistors are
calibrated for absolute accuracy and linearity at the factory.
Therefore, no user trims are necessary for full rated accuracy
over the operating temperature range.
The performance and versatility of the DACPORT is a result of
several recently-developed monolithic bipolar technologies. The
complete microprocessor interface and control logic is imple-
mented with integrated injection logic (I2L), an extremely dense
and low power logic structure that is process-compatible with
linear bipolar fabrication. The internal precision voltage reference
is the patented low voltage bandgap circuit which permits full-
accuracy performance on a single +5 V to +15 V power supply.
Thin-film silicon-chromium resistors provide the stability re-
quired for guaranteed monotonic operation over the entire oper-
ating temperature range (all grades), while recent advances in
laser-wafer-trimming of these thin-film resistors permit absolute
calibration at the factory to within ±1 LSB; thus no user-trims
for gain or offset are required. A new circuit design provides
voltage settling to ±1/2 LSB for a full-scale step in 800 ns.
3. The inclusion of a precision low voltage bandgap reference
eliminates the need to specify and apply a separate refer-
ence source.
4. The voltage switching structure of the AD558 DAC section
along with a high speed output amplifier and laser trimmed
resistors give the user a choice of 0 V to +2.56 V or 0 V to
+10 V output ranges, selectable by pin-strapping. Circuitry is
internally compensated for minimum settling time on both
ranges; typically settling to ±1/2 LSB for a full-scale 2.55 volt
step in 800 ns.
5. The AD558 is designed and specified to operate from a
single +4.5 V to +16.5 V power supply.
The AD558 is available in four performance grades. The AD558J
and K are specified for use over the 0°C to +70°C temperature
range, while the AD558S and T grades are specified for –55°C
to +125°C operation. The “J” and “K” grades are available
either in 16-pin plastic (N) or hermetic ceramic (D) DIPS.
They are also available in 20-pin JEDEC standard PLCC pack-
ages. The “S” and “T” grades are available in the 16-pin her-
metic ceramic DIP package.
6. Low digital input currents, 100 µA max, minimize bus load-
ing. Input thresholds are TTL/low voltage CMOS compat-
ible over the entire operating VCC range.
7. All AD558 grades are available in chip form with guaranteed
specifications from +25°C to TMAX. MIL-STD-883, Class B
visual inspection is standard on Analog Devices bipolar
chips. Contact the factory for additional chip information.
*Protected by U.S. Patent Nos. 3,887,863; 3,685,045; 4,323,795; Patents
Pending.
DACPORT is a registered trademark of Analog Devices, Inc.
8. The AD558 is available in versions compliant with MIL-
STD-883. Refer to Analog Devices Military Products Data-
book or current AD558/883B data sheet for detailed
specifications.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703