2 LC MOS Microprocessor-Compatible 14-Bit DAC AD7538 FEATURES FUNCTIONAL BLOCK DIAGRAM V DD All grades 14-bit monotonic over the full temperature range 23 Low cost, 14-bit upgrade for 12-bit systems AD7538 2 R FB 14-bit parallel load with double buffered inputs 1 14-BIT DAC V 3 Small 24-pin, 0.30 DIP and SOIC REF I OUT Low output leakage (<20 nA) over the full temperature range 4 AGND APPLICATIONS DAC REGISTER 20 LDAC Microprocessor-based control systems Digital audio 21 CS INPUT REGISTER Precision servo control 22 WR 14 Control and measurement in high temperature environments 619 5 24 DB13 TO DB0 DGND V SS Figure 1. GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7538 is a 14-bit monolithic CMOS digital-to-analog 1. Guaranteed Monotonicity. converter (DAC) that uses laser trimmed thin-film resistors to The AD7538 is guaranteed monotonic to 14-bits over the achieve excellent linearity. full temperature range for all grades. 2. Low Cost. The DAC is loaded by a single 14-bit wide word using standard The AD7538, with its 14-bit dynamic range, affords a low chip select and memory write logic. Double buffering, which is cost solution for 12-bit system upgrades. optional using LDAC, allows simultaneous updates in a system 3. Small Package Size. containing multiple AD7538s. The AD7538 is packaged in a small 24-pin, 0.3 DIP and a A novel low leakage configuration enables the AD7538 to 24-pin SOIC. exhibit excellent output leakage current characteristics over 4. Low Output Leakage. the specified temperature range. By tying V (Pin 24) to a negative voltage, it is possible to SS The AD7538 is manufactured using the linear-compatible achieve a low output leakage current at high temperatures. 2 5. Wide Power Supply Tolerance. CMOS (LC MOS) process. It is speed compatible with most The device operates on a +12 V to +15 V VDD, with a 5% microprocessors and accepts TTL or CMOS logic level inputs. tolerance on this nominal figure. All specifications are guaranteed over this range. 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 01139-001AD7538 TABLE OF CONTENTS Features .............................................................................................. 1 Equivalent Circuit Analysis ...................................................... 10 Applications ....................................................................................... 1 Digital Section ............................................................................ 10 Functional Block Diagram .............................................................. 1 Unipolar Binary Operation (2-Quadrant Multiplication) .... 10 General Description ......................................................................... 1 Bipolar Operation (4-Quadrant Multiplication) .................... 11 Product Highlights ........................................................................... 1 Low Leakage Configuration ...................................................... 11 Revision History ............................................................................... 2 Programmable Gain Amplifier ................................................. 12 Specif icat ions ..................................................................................... 3 Application Hints ........................................................................... 13 AC Performance Characteristics ................................................ 4 Output Offset .............................................................................. 13 Timing Characteristics ................................................................ 4 General Ground Management .................................................. 13 Timing Diagram ........................................................................... 5 Microprocessor Interfacing ....................................................... 13 Absolute Maximum Ratings ............................................................ 6 AD7538-to-8086 Interface ........................................................ 13 ESD Caution .................................................................................. 6 AD7538-to-MC68000 Interface ............................................... 13 Pin Configuration and Function Descriptions ............................. 7 Digital Feedthrough ................................................................... 14 Terminology ...................................................................................... 8 Outline Dimensions ....................................................................... 15 DAC Section ...................................................................................... 9 Ordering Guide .......................................................................... 16 Circuit Information ........................................................................ 10 REVISION HISTORY 1/09Rev. A to Rev. B Updated Format .................................................................. Universal Changes to Table 1 ............................................................................ 3 Updated Outline Dimensions ....................................................... 15 Changes to Ordering Guide .......................................................... 15 5/87Rev. 0 to Rev. A Rev. B Page 2 of 16