ad7247a Analog Devices, Inc., ad7247a Datasheet
ad7247a
Available stocks
Related parts for ad7247a
ad7247a Summary of contents
Page 1
... Loading Structure: AD7237A Single or Dual Supply Operation Low Power—165 mW typ in Single Supply GENERAL DESCRIPTION The AD7237A/AD7247A is an enhanced version of the industry standard AD7237/AD7247. Improvements include operation from supplies, faster interface times and better reference variations with V . Additional features include faster DD settling times ...
Page 2
... Measured with respect to REF IN and includes unipolar/bipolar offset error. 6 Sample tested @ + ensure compliance +10 V range is only available with V 14. Specifications subject to change without notice + + DGND = 0 V [AD7237A], GND = 0 V [AD7247A], REF unless otherwise noted.) MIN MAX Units 12 ...
Page 3
... ns, add AD7237A only. 1 ABSOLUTE MAXIMUM RATINGS (T = +25 C unless otherwise noted GND (AD7247A –0 + AGND, DGND (AD7237A –0 + –0 + AGND to DGND (AD7237A –0 ...
Page 4
... AD7237A/AD7247A AD7237A PIN FUNCTION DESCRIPTION (DIP PIN NUMBERS) Pin Mnemonic Description 1 REF INA Voltage Reference Input for DAC A. The reference voltage for DAC A is applied to this pin internally buffered before being applied to the DAC. The nominal reference voltage for correct operation of the AD7237A ...
Page 5
... AD7247A PIN FUNCTION DESCRIPTION (DIP PIN NUMBERS) Pin Mnemonic Description 1 REF OUT Voltage Reference Output. The internal 5 V analog reference is provided at this pin. To operate the part with internal reference, REF OUT should be connected to REF IN Output Offset Resistor for DAC B. This input configures the output ranges for DAC connected to ...
Page 6
... DAC latches is not changed. For the AD7237A it is measured with LDAC held high. For the AD7247A it is measured with CSA and CSB held high. DIGITAL CROSSTALK Digital crosstalk is the glitch impulse transferred to the output of one converter due to a change in digital code to the DAC latch of the other converter ...
Page 7
... Power Supply Current vs. Temperature Noise Spectral Density vs. Frequency Single Supply Sink Current vs. Output Voltage REV. 0 AD7237A/AD7247A DAC-to-DAC Linearity Matching Power Supply Rejection Ratio vs. Frequency Linearity vs. Power Supply Voltage –7– ...
Page 8
... Typical Performance Graphs section. INTERFACE LOGIC INFORMATION—AD7247A Table I shows the truth table for AD7247A operation. The part contains a single, parallel 12-bit latch for each DAC. It can be treated as two independent DACs, each with its own CS input and a common WR input ...
Page 9
... Table I. AD7247A Truth Table CSA CSB WR Function Data Transfer Data Transfer DAC A Latch Transparent DAC B Latch Transparent Both DAC Latches Transparent X = Don’t Care INTERFACE LOGIC INFORMATION—AD7237A The input loading structure on the AD7237A is configured for interfacing to microprocessors with an 8-bit-wide data bus. The part contains two 12-bit latches per DAC— ...
Page 10
... Figure 9 shows the connection diagram for bipolar opera- tion for DAC A of the AD7247A. An AD586 provides the refer- ence voltage for the DAC but this could be provided by the on-chip reference by connecting REF OUT to REF IN. The code table for bipolar operation is shown in Table IV ...
Page 11
... Figure 10. AD7247A to ADSP-2101 Interface AD7247A—8086 Interface Figure 11 shows an interface between the AD7247A and the 8086 microprocessor. The 12-bit word is written to the selected DAC latch of the AD7247A in a single MOV instruction, and the analog output responds immediately. Figure 11. AD7247A to 8086 Interface REV. 0 AD7237A/AD7247A AD7247A— ...
Page 12
... AD7237A/AD7247A Either high byte or low byte data can be written first to the in- put latch. A write to the AD7237A DAC Latch address transfers the data from the input latches to the respective DAC latches and updates both analog outputs. Alternatively, the LDAC in- put can be asynchronous or can be common to a number of AD7237As for simultaneous updating of a number of voltage channels ...