Asynchronous-SPDIF-Mixer
DADDesign-Projects
"Asynchronous SPDIF Mixer" synchronizes and mixes up to three asynchronous S/PDIF streams into a 48 kHz output. Running on an STM32H743 and developed in C++ with CubeIDE, it compensates for drift with interpolation. A custom KiCad-designed PCB hosts this real-time audio processing solution.
Components (64)
| Reference | Value | Description |
|---|---|---|
| U1 | STM32H743VIT6 | |
| U2 | 74HCU04 | Hex Inverter |
| U3 | MAX3490 | Full duplex RS-485/RS-422, 10Mbps, slew-rate limited, no low-power shutdown, no with receiver/driver enable, 32 receiver drive capability, SOIC-8 |
| U4 | W25Q64 | 16Mb Serial Flash Memory, Standard/Dual/Quad SPI, SOIC-8 |
| U5,U6 | DIR9001 | |
| U7 | AMS1117-3.3 | 1A Low Dropout regulator, positive, 3.3V fixed output, SOT-223 |
| C1-C6,C8,C10-C12,C15,C17,C18,C21,C22,C26-C28,C33-C36,C39,C40 | 100n | Unpolarized capacitor |
| C7,C9 | 1u | Unpolarized capacitor |
| C13,C14 | 2.2u | Unpolarized capacitor |
| C16,C19,C20,C23 | 10u | Polarized capacitor |
| C24,C25 | 100u | Polarized capacitor |
| C29,C30 | 15p | Unpolarized capacitor |
| C31,C37,C42,C43 | 4.7n | Unpolarized capacitor |
| C32,C38,C41,C44 | 68n | Unpolarized capacitor |
| D1 | PRTR5V0U2X | Ultra low capacitance double rail-to-rail ESD protection diode, SOT-143 |
| D2 | Alim | Light emitting diode |
| D3,TP14 | In3 | Light emitting diode,test point |
| D4,TP13 | In2 | Light emitting diode,test point |
| D5,TP7 | In1 | Light emitting diode,test point |
| FB1 | 1K 100MHz | Ferrite bead |
| J1 | Power In | Generic connector, single row, 01x02, script generated |
| J2 | Debug | Generic connector, single row, 01x04, script generated |
| J3 | USB_C_Receptacle_USB2.0_16P | USB 2.0-only 16P Type-C Receptacle connector |
| J4 | S/PDIF-Out | coaxial connector (BNC, SMA, SMB, SMC, Cinch/RCA, LEMO, ...) |
| J5 | S/PDIF-In1 | coaxial connector (BNC, SMA, SMB, SMC, Cinch/RCA, LEMO, ...) |
| J6 | S/PDIF-In2 | coaxial connector (BNC, SMA, SMB, SMC, Cinch/RCA, LEMO, ...) |
| J7 | S/PDIF-In3 | coaxial connector (BNC, SMA, SMB, SMC, Cinch/RCA, LEMO, ...) |
| JP1 | CFG1 | Jumper, 2-pole, small symbol, open |
| JP2 | CFG2 | Jumper, 2-pole, small symbol, open |
| JP3 | CFG3 | Jumper, 2-pole, small symbol, open |
| JP4 | CFG4 | Jumper, 2-pole, small symbol, bridged |
| JP5 | PSCK1_1 | Jumper, 2-pole, small symbol, open |
| JP6 | PSCK0_1 | Jumper, 2-pole, small symbol, open |
| JP7 | FMT1_1 | Jumper, 2-pole, small symbol, open |
| JP8 | FMT0_1 | Jumper, 2-pole, small symbol, bridged |
| JP9 | PSCK1_2 | Jumper, 2-pole, small symbol, open |
| JP10 | PSCK0_2 | Jumper, 2-pole, small symbol, open |
| JP11 | FMT1_2 | Jumper, 2-pole, small symbol, open |
| JP12 | FMT0_2 | Jumper, 2-pole, small symbol, bridged |
| PS1 | B1205_2W | |
| R1,R20,R37,R38 | 0 | Resistor |
| R2-R5,R15-R18,R26-R29 | 10k | Resistor |
| R6,R7 | 5.1K | Resistor |
| R8,R24,R31,R35 | 47k | Resistor |
| R9,R10,R12,R13 | 4.7K | Resistor |
| R11,R14 | 4.7k | Resistor |
| R19,R21,R23,R30,R34 | 75 | Resistor |
| R22,R33 | 680 | Resistor |
| R25,R32,R36 | 2.2k | Resistor |
| SW1 | BOOT | Push button switch, generic, two pins |
| SW2 | RESET | Push button switch, generic, two pins |
| T1-T4 | PE 65612 | Transformer, single primary, single secondary |
| TP1 | BCLK1 | test point |
| TP2 | LRCLK1 | test point |
| TP3 | DOUT1 | test point |
| TP4 | ERROR1 | test point |
| TP5 | NO_AUDIO1 | test point |
| TP6 | Out | test point |
| TP8 | BCLK2 | test point |
| TP9 | LRCLK2 | test point |
| TP10 | DOUT2 | test point |
| TP11 | ERROR2 | test point |
| TP12 | NO_AUDIO2 | test point |
| Y1 | 25Mhz | Two pin crystal |