Datasheet AD1580 (Analog Devices) - 10

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AD1580
The AD1580 is ideal for creating the reference level to use with 12-bit
3.3V
multiplying DACs, such as the AD7943, AD7945, and AD7948. In the single-supply bias mode (see Figure 26), the impedance
VDD RBF C1
seen looking into the IOUT2 terminal changes with DAC code. If
IOUT1
the AD1580 drives I
V
OUT2 and AGND directly, less than 0.2 LSBs
REF VIN DAC I A1 OUT2 VOUT
of additional linearity error results. The buffer amp eliminates any linearity degradation that could result from variations in
AD7943/ AGND A1: OP295 AD7945/ AD822
the reference level.
OP2283 AD7948 DGND 3.3V 41.2kΩ A1 AD1580
026
SIGNAL GROUND
00700- Figure 26. Single-Supply System Rev. F | Page 10 of 12 Document Outline Features Applications General Description Pin Configurations Revision History Specifications Absolute Maximum Ratings ESD Caution Typical Performance Characteristics Theory of Operation Applying the AD1580 Temperature Performance Voltage Output Nonlinearity vs. Temperature Reverse Voltage Hysteresis Output Impedance vs. Frequency Noise Performance and Reduction Turn-On Time Transient Response Precision Micropower Low Dropout Reference Using the AD1580 with 3 V Data Converters Outline Dimensions Ordering Guide Package Branding Information