Hardware/Mezzanine/audio AD-DA
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== Input range == | == Input range == | ||
− | The board input signals are brougth to differential op-amp circuits with | + | The board input signals are brougth to a first stage of differential op-amp circuits with: |
* <math>R_{15} = R_{17} = R_{16} = R_{18} = R_{36} = R_{38} = R_{37} = R_{39}</math> | * <math>R_{15} = R_{17} = R_{16} = R_{18} = R_{36} = R_{38} = R_{37} = R_{39}</math> | ||
− | * <math>R_{8} / R_{17} = R_{ | + | * <math>gain_1 = R_{17} / R_{8} = R_{15} / R_{10} = R_{18} / R_{12} = R_{16} / R_{14} = R_{38} / R_{29} = R_{36} / R_{31} = R_{39} / R_{33} = R_{37} / R_{35}</math> |
+ | * <math>pos\_offset / pos\_supply = R_{17} / R_{7} = R_{18} / R_{11} = R_{38} / R_{28} = R_{39} / R_{32}</math> | ||
+ | * <math>neg\_offset / neg\_supply = R_{17} / R_{10} = R_{18} / R_{13} = R_{38} / R_{30} = R_{39} / R_{34}</math> | ||
+ | |||
+ | The ADC inputs range from 0 V to 5V. | ||
+ | |||
+ | The output of this first circuit is decoupled and brought to a second stage built around the in-circuit op-amp of the ADC. | ||
+ | The gain of the second stage is: | ||
+ | * <math>gain_2 = R_{23} / R_{21} = R_{24} / R_{22} = R_{44} / R_{42} = R_{45} / R_{43}</math> | ||
[[Category:Hardware]] [[Category:Mezzanine]] | [[Category:Hardware]] [[Category:Mezzanine]] |
Revision as of 14:23, 5 November 2012
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Audio AD/DA mezzanine board
This board has been developed as a low-cost replacement of the high-speed AD-DA board. It features:
Power supply
The supply from the connector is used to power the TL064 op amps. They can be powered between ±3.5 V and ±18V.
A TPS54227 DC/DC converter generates 6.5 V from the power supply and is followed by a 5 V regulator.
Hence, the minimal power supply range is about ±7 V.
Input range
The board input signals are brougth to a first stage of differential op-amp circuits with:
- R15 = R17 = R16 = R18 = R36 = R38 = R37 = R39
- gain1 = R17 / R8 = R15 / R10 = R18 / R12 = R16 / R14 = R38 / R29 = R36 / R31 = R39 / R33 = R37 / R35
- pos_offset / pos_supply = R17 / R7 = R18 / R11 = R38 / R28 = R39 / R32
- neg_offset / neg_supply = R17 / R10 = R18 / R13 = R38 / R30 = R39 / R34
The ADC inputs range from 0 V to 5V.
The output of this first circuit is decoupled and brought to a second stage built around the in-circuit op-amp of the ADC. The gain of the second stage is:
- gain2 = R23 / R21 = R24 / R22 = R44 / R42 = R45 / R43