SLAAE64 may   2023 AFE58JD48 , DAC81001 , DAC8801 , DAC8830 , OPA2210 , REF5010 , REF5040 , THS4130

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Proposed Topologies
    1. 2.1 Proposal 1: Using R-2R DAC (DAC8830)
      1. 2.1.1 Highlighted Products
        1. 2.1.1.1 DAC8830
        2. 2.1.1.2 OPA2210
        3. 2.1.1.3 THS4130
        4. 2.1.1.4 REF5040
      2. 2.1.2 Design Circuit
      3. 2.1.3 PSpice-TI Simulation
    2. 2.2 Proposal 2: Using M-DAC (DAC8801)
      1. 2.2.1 Highlighted Products
        1. 2.2.1.1 DAC8801
        2. 2.2.1.2 OPA2210
        3. 2.2.1.3 THS4130
        4. 2.2.1.4 REF5010
      2. 2.2.2 Design Circuit
      3. 2.2.3 PSpice-TI Simulation
    3. 2.3 Proposal 3: Using Low-Noise R-2R DAC (DAC81001)
      1. 2.3.1 Highlighted Products
        1. 2.3.1.1 DAC81001
        2. 2.3.1.2 OPA2210
        3. 2.3.1.3 THS4130
        4. 2.3.1.4 REF5010
      2. 2.3.2 Design Circuit
      3. 2.3.3 PSpice-TI Simulation
  6. 3Conclusion
  7. 4References

3 Conclusion

This article described three approaches to design a low-noise drive circuit for the control voltage in TGC applications. For any ultrasound application, TGC is an important phenomenon. The ultrasound receive AFE includes a voltage-controlled attenuator for implementing TGC functionality that operates using a control voltage generated using external circuitry. The control voltage characteristics are used for defining the external DAC and amplifier specifications. This application notes explained the details of each approach. Table 3-1 compares each approach.

Table 3-1 Comparison of Different Approaches for TGC Circuit
SchemeProposal 1
(R-2R DAC)		Proposal 2
(M-DAC)		Proposal 3
(Low-noise
R-2R DAC)
DAC deviceDAC8830DAC8801DAC81001
DAC Resolution and Type16-bit (R-2R-DAC with Unbuffered Voltage)14-bit (M-DAC with Unbuffered Current)16-bit (R-2R-DAC with Unbuffered Current)
DAC noise (nV/)10127
Number of op-amps2 (OPA2210)2 (OPA2210)2 (OPA2210)
Number of FDAs1 (THS4130)1 (THS4130)1 (THS4130)
Reference Voltage4.096 V (REF5040)10 V (REF5010)10 V (REF5010)
Simulated total output noise (nV/) at 1 kHz4.081.700.97
Power Supplies Required
  • ±6 V for op-amp supplies and REF
  • 5 V for DAC VDD
  • ±12.5 V for op-amp supplies and REF
  • 5 V for DAC VDD
  • ±12.5V for op-amp supplies and REF
  • 5 V for DAC VDD
Drive channel1632–64≤ 192