SBAA631 January   2025 DAC80508 , INA592 , XTR111 , XTR300 , XTR305

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Analog Output Module Specification
  6. 3Analog Output Module Structure
  7. 4Multi-Channel Output Architectures
    1. 4.1 Fully Integrated DAC Architecture
    2. 4.2 Low Voltage DAC Plus an Output Buffer
    3. 4.3 Track and Hold Multiplexed Output
  8. 5Single-Channel Output Architectures
    1. 5.1 Fully Integrated DAC
    2. 5.2 Low-Voltage DAC Plus an Output Buffer
    3. 5.3 Pulse-Width Modulation Plus a Buffer
  9. 6Output Buffers
    1. 6.1 Unidirectional Current Buffer
    2. 6.2 Bidirectional Current Buffer
    3. 6.3 Voltage Buffer
    4. 6.4 Combined Voltage or Current Buffer
  10. 7Summary
  11. 8References

4.2 Low Voltage DAC Plus an Output Buffer

This is popular architecture as low voltage DAC are readily available. Even the non-buffered DAC can be used making more parts available to select from. DAC80504 is an excellent DAC for such application. DAC80504 is a family of unipolar 5V buffered voltage output DAC with integrated REF (2ppm/°C), only 5us settling time, programmable output range, and INL=1 LSB in small package. The DAC does not have sense pin, but with output buffers this is not necessary, as the output compensation is done by the buffer feedback loop.

The large family of devices makes sure the designer can find the resolution and the number of channels required. The output buffer options are discussed in detail in a later section.

Table 4-3 DAC80508 Device Family
Channels12 bit14 bit16 bit
1DAC60501DAC70501DAC80501
2DAC60502DAC70502DAC80502
4DAC60504DAC70504DAC80504
8DAC60508DAC70508DAC80508

The DAC plus buffer architecture is a must if higher output current drive is needed, as most integrated DACs have limited current drive. Also if very fast settling is required as a designer can combine fast low voltage DACs and wide bandwidth buffers, but hardly can find any integrated high voltage DAC with faster than 10us settling time.