DAC8248EW AD [Analog Devices], DAC8248EW Datasheet

no-image

DAC8248EW

Manufacturer Part Number
DAC8248EW
Description
Dual 12-Bit 8-Bit Byte Double-Buffered CMOS D/A Converter
Manufacturer
AD [Analog Devices]
Datasheet
a
GENERAL DESCRIPTION
The DAC8248 is a dual 12-bit, double-buffered, CMOS digital-
to-analog converter. It has an 8-bit wide input data port that inter-
faces directly with 8-bit microprocessors. It loads a 12-bit word in
two bytes using a single control; it can accept either a least signifi-
cant byte or most significant byte first. For designs with a 12-bit or
16-bit wide data path, choose the DAC8222 or DAC8221.
REV. B
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.
FEATURES
Two Matched 12-Bit DACs on One Chip
12-Bit Resolution with an 8-Bit Data Bus
Direct Interface with 8-Bit Microprocessors
Double-Buffered Digital Inputs
RESET to Zero Pin
12-Bit Endpoint Linearity ( 1/2 LSB) Over Temperature
Latch-Up Resistant
Improved ESD Resistance
Packaged in a Narrow 0.3" 24-Pin DIP and 0.3" 24-Pin
Available in Die Form
APPLICATIONS
Multichannel Microprocessor-Controlled Systems
Robotics/Process Control/Automation
Automatic Test Equipment
Programmable Attenuator, Power Supplies, Window
Instrumentation Equipment
Battery Operated Equipment
5 V to
SOL Package
Comparators
15 V Single Supply Operation
FUNCTIONAL BLOCK DIAGRAM
Double-Buffered CMOS D/A Converter
The DAC8248’s double-buffered digital inputs allow both
DAC’s analog output to be updated simultaneously. This is par-
ticularly useful in multiple DAC systems where a common
LDAC signal updates all DACs at the same time. A single
RESET pin resets both outputs to zero.
The DAC8248’s monolithic construction offers excellent DAC-
to-DAC matching and tracking over the full operating tempera-
ture range. The DAC consists of two thin-film R-2R resistor
ladder networks, two 12-bit, two 8-bit, and two 4-bit data regis-
ters, and control logic circuitry. Separate reference input and
feedback resistors are provided for each DAC. The DAC8248
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
24-Pin 0.3" Cerdip (W Suffix),
24-Pin Epoxy DIP (P Suffix),
Dual 12-Bit (8-Bit Byte)
24-Pin SOL (S Suffix)
PIN CONNECTIONS
DAC8248
(continued on page 4)
Fax: 617/326-8703

Related parts for DAC8248EW

DAC8248EW Summary of contents

Page 1

FEATURES Two Matched 12-Bit DACs on One Chip 12-Bit Resolution with an 8-Bit Data Bus Direct Interface with 8-Bit Microprocessors Double-Buffered Digital Inputs RESET to Zero Pin 12-Bit Endpoint Linearity ( 1/2 LSB) Over Temperature ...

Page 2

DAC8248–SPECIFICATIONS ELECTRICAL CHARACTERlSTICS T = Full Temp Range specified in Absolute Maximum Ratings; unless otherwise noted. Specifications apply for DAC A and DAC B.) A Parameter STATIC ACCURACY Resolution Relative Accuracy Differential Nonlinearity 1 Full-Scale Gain Error Gain Temperature Coefficient ...

Page 3

Parameter Symbol Switching Characteristics (Notes 2, 8) LSB/MSB Select to Write Set-Up Time t CBS LSB/MSB Select to Write Hold Time t CBH DAC Select to Write Set-Up Time t AS DAC Select to Write Hold Time t AH LDAC ...

Page 4

... EW, FW, FP Versions . . . . . . . . . . . . . . . . – +85 C GP, HP, HS Versions . . . . . . . . . . . . . . . . . . . +70 C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . +150 C Storage Temperature . . . . . . . . . . . . . . . . . . – +150 C Lead Temperature (Soldering, 60 sec +300 C Relative Accuracy Model (+ + DAC8248AW 1/2 LSB DAC8248EW 1/2 LSB DAC8248GP 1/2 LSB DAC8248FW 1 LSB DAC8248HP 1 LSB DAC8248FP 1 LSB 3 DAC8248HS ...

Page 5

Die Size 0.124 0.132 inch, 16,368 sq. mils (3.15 3.55 mm, 10.56 sq. mm) WAFER TEST LIMITS @ + Parameter Symbol Relative Accuracy INL Differential Nonlinearity DNL 1 Full-Scale Gain Error G ...

Page 6

DAC8248 –Typical Performance Characteristics Channel-to-Channel Matching (DAC A & B are Superimposed) Nonlinearity vs. V REF Nonlinearity vs. Code (DAC A & B are Superimposed) Differential Nonlinearity vs. V REF Nonlinearity vs. V REF Nonlinearity vs. Code ...

Page 7

Full-Scale Gain Error vs. Temperature Supply Current vs. Logic Input Voltage Output Leakage Current vs. Temperature REV. B Logic Input Threshold Voltage vs. Supply Voltage ( Multiplying Mode Frequency Response vs. Digital Code Analog Crosstalk vs. Frequency –7– ...

Page 8

DAC8248 Four Cycle Update PARAMETER DEFINITIONS RESOLUTION (N) The resolution of a DAC is the number of states (2 full-scale range (FSR) is divided (or resolved) into; where n is equal to the number of bits. RELATIVE ACCURACY (INL) Relative ...

Page 9

Figure 2. N-Channel Current Steering Switch The binary-weighted currents are switched between I AGND by the transistor switches. Selection between I AGND is determined by the digital input code important to keep the voltage difference between I nals ...

Page 10

DAC8248 Figure 4. Four Cycle Update Timing Diagram Figure 5. Five Cycle Update Timing Diagram –10– REV. B ...

Page 11

AUTOMATIC DATA TRANSFER MODE Data may be transferred automatically from the input register to the DAC register. The first cycle loads the first data byte into the input register; the second cycle loads the second data byte and simultaneously transfers ...

Page 12

DAC8248 INTERFACE CONTROL LOGIC PIN FUNCTIONS LSB/MSB – (PIN 17) LEAST SIGNIFICANT BIT (Active Low)/ MOST SIGNIFICANT BIT (Active High). Selects lower 8-bits (LSBs) or upper 4-bits (MSBs); either can be loaded first used with the WR signal ...

Page 13

DAC’s digital inputs with 0000 0000 0000 and adjusting the op amp’s offset voltage rec- ommended that the op amp offset voltage be adjusted to less than 10 LSB (244 ...

Page 14

DAC8248 ground as shown in Figure 9. The output voltage will be be- tween +5 V and +10 V depending on the digital input code. The output expression is given by (D/4096)(V OUT OS where V = ...

Page 15

Figure 10. Single Supply Operation (Voltage Switching Mode) Figure 11. Digitally-Programmable Window Detector (Upper/Lower Limit Detector) MICROPROCESSOR INTERFACE CIRCUITS The DAC8248s versatile loading structure allows direct inter- face to an 8-bit microprocessor. Its simplicity reduces the num- ber of required ...

Page 16

Figure 12. DAC8248 to MC6809 Interface 0.200 (5.08) 0.200 (5.08) 0.125 (3.18) 24-Lead Plastic DIP (N-24) 1.275 (32.30) 1.125 (28.60 0.280 (7.11) 0.240 (6.10 PIN 1 0.060 (1.52) 0.210 0.015 (0.38) (5.33) MAX 0.200 (5.05) 0.125 ...

Related keywords