DatasheetsPDF.com

AD7628 Dataheets PDF



Part Number AD7628
Manufacturers Analog Devices
Logo Analog Devices
Description CMOS Dual 8-Bit Buffered Multiplying DAC
Datasheet AD7628 DatasheetAD7628 Datasheet (PDF)

a FEATURES On-Chip Latches for Both DACs +12 V to +15 V Operation DACs Matched to 1% Four Quadrant Multiplication TTL/CMOS Compatible from +12 V to +15 V Latch Free (Protection Schottkys not Required) APPLICATIONS Disk Drives Programmable Filters X-Y Graphics Gain/Attenuation CMOS Dual 8-Bit Buffered Multiplying DAC AD7628 FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7628 is a monolithic dual 8-bit digital/analog converter featuring excellent DAC-to-DAC matching. It .

  AD7628   AD7628


Document
a FEATURES On-Chip Latches for Both DACs +12 V to +15 V Operation DACs Matched to 1% Four Quadrant Multiplication TTL/CMOS Compatible from +12 V to +15 V Latch Free (Protection Schottkys not Required) APPLICATIONS Disk Drives Programmable Filters X-Y Graphics Gain/Attenuation CMOS Dual 8-Bit Buffered Multiplying DAC AD7628 FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7628 is a monolithic dual 8-bit digital/analog converter featuring excellent DAC-to-DAC matching. It is available in small 0.3" wide 20-pin DIPs and in 20-terminal surface mount packages. Separate on-chip latches are provided for each DAC to allow easy microprocessor interface. Data is transferred into either of the two DAC data latches via a common 8-bit TTL/CMOS compatible input port. Control input DAC A/DAC B determines which DAC is to be loaded. The AD7628’s load cycle is similar to the write cycle of a random access memory, and the device is bus compatible with most 8-bit microprocessors, including 6502, 6809, 8085, Z80. The device operates from a +12 V to +15 V power supply and is TTL-compatible over this range. Power dissipation is a low 20 mW. Both DACs offer excellent four quadrant multiplication characteristics with a separate reference input and feedback resistor for each DAC. 1. DAC to DAC matching: since both of the AD7628 DACs are fabricated at the same time on the same chip, precise matching and tracking between DAC A and DAC B is inherent. The AD7628’s matched CMOS DACs make a whole new range of applications circuits possible, particularly in the audio, graphics and process control areas. 2. Small package size: combining the inputs to the on-chip DAC latches into a common data bus and adding a DAC A/ DAC B select line has allowed the AD7628 to be packaged in a small 20-pin 0.3" wide DIP, 20-pin SOIC, 20-terminal PLCC and 20-terminal LCC. 3. TTL-Compatibility: All digital inputs are TTL-compatible over a +12 V to +15 V power supply range. 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 World Wide Web Site: http://www.analog.com Fax: 617/326-8703 © Analog Devices, Inc., 1996 = +10.8 V to +15.75 V, V AD7628–SPECIFICATIONS (V otherwise noted) DD REF A = VREF B = +10 V; OUT A = OUT B = 0 V unless Parameter STATIC PERFORMANCE 2 Resolution Relative Accuracy Differential Nonlinearity Gain Error TA = +25؇C1 8 ± 1/2 ±1 ±2 TA = –40؇C to +85؇C 8 ± 1/2 ±1 ±3 TA = –55؇C to +125؇C1 8 ± 1/2 ±l ±3 Units Bits LSB max LSB max LSB max Test Conditions/Comments This is an Endpoint Linearity Specification All Grades Guaranteed Monotonic Over Full Operating Temperature Range Measured Using Internal RFB A and RFB B. Both DAC Latches Loaded with 11111111. Gain Error is Adjustable Using Circuits of Figures 4 and 5. Gain Temperature Coefficient 3 ∆Gain/ ∆Temperature Output Leakage Current OUT A (Pin 2) OUT B (Pin 20) Input Resistance (V REFA, VREFB) VREFA/VREFB Input Resistance Match DIGITAL INPUTS 4 Input High Voltage (V IH) Input Low Voltage (V IL) Input Current (IIN) Input Capacitance DB0–DB7 WR, CS, DACA/DACB SWITCHING CHARACTERISTICS 3 See Timing Diagram Chip Select to Write Set Up Time (t CS) Chip Select to Write Hold Time (t CH) DAC Select to Write Set Up Time (t AS) DAC Select to Write Hold Time (t AH) Data Valid to Write Set Up Time (t DS) Data Valid to Write Hold Time (t DH) Write Pulse Width (t WR) POWER SUPPLY IDD, K Grade B, T Grades All Grades ± 0.0035 ± 50 ± 50 8 15 ±1 2.4 0.8 ±1 10 15 ± 200 ± 200 8 15 ±1 2.4 0.8 ± 10 10 15 ± 0.0035 ± 200 ± 200 8 15 ±1 2.4 0.8 ± 10 10 15 %/°C max nA max nA max kΩ min kΩ max % max V min V max µA max pF max pF max DAC Latches Loaded with 00000000 Input Resistance TC = –300 ppm/ °C, Typical Input Resistance is 11 k Ω VIN = 0 or VDD 160 10 160 10 160 10 150 2 2 100 160 10 160 10 160 10 170 2 2.5 500 210 10 210 10 210 10 210 ns min ns min ns min ns min ns min ns min ns min mA mA µA See Figure 3 All Digital Inputs V IL or VIH All Digital Inputs V IL or VIH All Digital Inputs 0 V or V DD 2.5 500 Specifications subject to change without notice. These characteristics are included for Design Guidance only and are not subject to test. VDD = +10.8 V to +15.75 V. (Measured Using Recommended PC Board Layout (Figure 7) and AD644 as Output Amplifiers) Parameter DC SUPPLY REJECTION (∆GAIN/∆VDD) CURRENT SETTLING TIME TA = +25؇C1 0.01 350 TA = –40؇C to +85؇C1 0.02 400 TA = –55؇C to +125؇π C1 0.02 400 Units Test Conditions/Comments AC PERFORMANCE CHARACTERISTICS % per % max ∆VDD = ± 5% ns max To 1/2 LSB OutA/OutB Load = 100 Ω. WR = CS = 0 V. DB0–DB7 = 0 V to V DD or VDD to 0 V For Cod.


AD760 AD7628 AD7650


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)