# Teensy 4-Track Audio Looper ## Description Compact Teensy 4.1-based 4-track audio looper with SGTL5000 audio shield, stereo line I/O, microSD storage, pots, buttons, LEDs, and rotary encoder control surface. ## Project Details - **Owner:** chrubble - **Created:** 6/7/2026 - **Last Updated:** 6/7/2026 - **Visibility:** Public ## Key Components ### D1 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Role: Human Interface - Manufacturer Name: Würth Elektronik - Manufacturer Part Number: 150060VS55040 - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf **Pins:** - A [pin 2] - K [pin 1] ### ENC1 — [EC12D1564402](https://www.flux.ai/lcsc/ec12d1564402~8pf4.md) - Part Type: Rotary Encoders - Package or Case Code: SW-TH_EC12D1564402 - LCSC Part Number: C444933 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410122028_ALPSALPINE-EC12D1564402_C444933.pdf - Role: Human Interface - Manufacturer Name: ALPSALPINE(阿尔卑斯阿尔派) - JLCPCB Part Class: Extended Part - Role Details: ALPS Alpine EC12D1564402 quadrature encoder A/B plus push switch to Teensy digital inputs with pull-ups. - Product Info Url: https://lcsc.com/product-detail/Coded-Rotary-Switches_ALPS-Electric-EC12D1564402_C444933.html - Manufacturer Part Number: EC12D1564402 **Pins:** - 6 [pin 6] - 7 [pin 7] - A [pin A] - B [pin B] - C [pin C] - D [pin D] - E [pin E] ### J1 — [DS1139-06-08SS4BSR](https://www.flux.ai/adrian95/ds1139-06-08ss4bsr~yrz.md) - Role Details: SPI microSD storage for recorded loops and load/save functions. - Part Type: Connector - Manufacturer Name: CONNFLY Elec - Connector Type: Card Edge Connectors - Manufacturer Part Number: DS1139-06-08SS4BSR - LCSC Part Number: C86574 - License: https://creativecommons.org/licenses/by/4.0/ - Role: Storage Connector - Datasheet URL: https://www.lcsc.com/datasheet/C86574.pdf **Pins:** - CLK [pin 5] - CMD [pin 3] - D0 [pin 7] - D1 [pin 8] - D2 [pin 1] - D3 [pin 2] - GND [pin 9] - GND [pin 12] - GND [pin 10] - GND [pin 11] - VDD [pin 4] - VSS [pin 6] ### J2 — [SJ-3523-SMT-TR](https://www.flux.ai/vasy_skral/sj-3523-smt-tr~6n4.md) - Role Details: Panel/PCB TRS jack for line-level stereo audio; sleeve ties to common ground, not headphone VGND. - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector - Manufacturer Name: CUI Devices - Datasheet URL: https://www.cuidevices.com/product/resource/sj-352x-smt.pdf - Manufacturer Part Number: SJ-3523-SMT-TR - Role: Audio Connector **Pins:** - R [pin R] - S [pin S] - T [pin T] ### J3 — [SJ-3523-SMT-TR](https://www.flux.ai/vasy_skral/sj-3523-smt-tr~6n4.md) - Datasheet URL: https://www.cuidevices.com/product/resource/sj-352x-smt.pdf - Manufacturer Part Number: SJ-3523-SMT-TR - Manufacturer Name: CUI Devices - Part Type: Connector - Role: Audio Connector - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Panel/PCB TRS jack for line-level stereo audio; sleeve ties to common ground, not headphone VGND. **Pins:** - R [pin R] - S [pin S] - T [pin T] ### LED1 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Manufacturer Part Number: 150060VS55040 - Role: Human Interface - Manufacturer Name: Würth Elektronik - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### LED10 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Manufacturer Part Number: 150060VS55040 - Manufacturer Name: Würth Elektronik - Role: Human Interface **Pins:** - A [pin 2] - K [pin 1] ### LED2 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Manufacturer Name: Würth Elektronik - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Role: Human Interface - Manufacturer Part Number: 150060VS55040 - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf **Pins:** - A [pin 2] - K [pin 1] ### LED3 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Manufacturer Part Number: 150060VS55040 - Role: Human Interface - Manufacturer Name: Würth Elektronik - Part Type: LED - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. **Pins:** - A [pin 2] - K [pin 1] ### LED4 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Manufacturer Name: Würth Elektronik - Role: Human Interface - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Manufacturer Part Number: 150060VS55040 - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf **Pins:** - A [pin 2] - K [pin 1] ### LED5 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Manufacturer Part Number: 150060VS55040 - Role: Human Interface - Manufacturer Name: Würth Elektronik - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### LED6 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Manufacturer Name: Würth Elektronik - Role: Human Interface - Manufacturer Part Number: 150060VS55040 **Pins:** - A [pin 2] - K [pin 1] ### LED7 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Manufacturer Name: Würth Elektronik - Manufacturer Part Number: 150060VS55040 - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - Role: Human Interface **Pins:** - A [pin 2] - K [pin 1] ### LED8 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Manufacturer Part Number: 150060VS55040 - Manufacturer Name: Würth Elektronik - Role: Human Interface - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### LED9 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040~c2q.md) - Role: Human Interface - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Green indicator LED driven by 74HC595 output through 1k current limit resistor. - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Part Type: LED - Manufacturer Name: Würth Elektronik - Manufacturer Part Number: 150060VS55040 **Pins:** - A [pin 2] - K [pin 1] ### S1 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Manufacturer Part Number: B3FS-1002P - Role: Switching - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Part Type: Electromechanical Components - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S10 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Manufacturer Name: Omron Electronics Inc-EMC Div - Role: Switching - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S11 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Manufacturer Name: Omron Electronics Inc-EMC Div - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S12 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Manufacturer Part Number: B3FS-1002P - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Manufacturer Name: Omron Electronics Inc-EMC Div - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S13 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Manufacturer Name: Omron Electronics Inc-EMC Div - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S14 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role: Switching - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S15 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Manufacturer Part Number: B3FS-1002P - Part Type: Electromechanical Components - Role: Switching - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S16 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Manufacturer Name: Omron Electronics Inc-EMC Div - Role: Switching - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S2 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role: Switching - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S3 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Manufacturer Part Number: B3FS-1002P - Part Type: Electromechanical Components - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role: Switching - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Omron Electronics Inc-EMC Div - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S4 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - Role: Switching - Manufacturer Name: Omron Electronics Inc-EMC Div - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S5 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Role: Switching - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Manufacturer Name: Omron Electronics Inc-EMC Div - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: B3FS-1002P - Part Type: Electromechanical Components **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S6 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role: Switching - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: B3FS-1002P - Part Type: Electromechanical Components - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S7 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - Manufacturer Name: Omron Electronics Inc-EMC Div - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S8 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Part Type: Electromechanical Components - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Manufacturer Part Number: B3FS-1002P - Role: Switching - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S9 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Part Type: Electromechanical Components - Manufacturer Part Number: B3FS-1002P - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - Manufacturer Name: Omron Electronics Inc-EMC Div - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### SW1 — [B3FS-1002P](https://www.flux.ai/adrian95/b3fs-1002p.md) - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3fs.pdf - Role Details: SPST-NO pushbutton connects input to ground when pressed; firmware uses pull-ups. - License: https://creativecommons.org/licenses/by/4.0/ - Role: Switching - Manufacturer Part Number: B3FS-1002P - Part Type: Electromechanical Components - Manufacturer Name: Omron Electronics Inc-EMC Div **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U1 — [Teensy 4.1](https://www.flux.ai/adrian95/teensy-4p1~xp5.md) - Role Details: Teensy 4.1 controller for 4-track looper firmware and all control interfaces. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2942/DEV-16996_Web.pdf - Manufacturer Part Number: DEV-16996 - Part Type: Development Board - Role: Main MCU - Manufacturer Name: SparkFun Electronics **Pins:** - 0_ [pin 2] - 1_ [pin 3] - 10_ [pin 12] - 11_ [pin 13] - 12_ [pin 14] - 13_ [pin 35] - 14_ [pin 36] - 15_ [pin 37] - 16_ [pin 38] - 17_ [pin 39] - 18_ [pin 40] - 19_ [pin 41] - 2_ [pin 4] - 20_ [pin 42] - 21_ [pin 43] - 22_ [pin 44] - 23_ [pin 45] - 24_ [pin 16] - 25_ [pin 17] - 26_ [pin 18] - 27_ [pin 19] - 28_ [pin 20] - 29_ [pin 21] - 3_ [pin 5] - 30_ [pin 22] - 31_ [pin 23] - 32_ [pin 24] - 33_ [pin 25] - 34_ [pin 26] - 35_ [pin 27] - 36_ [pin 28] - 37_ [pin 29] - 38_ [pin 30] - 39_ [pin 31] - 3V [pin 15] - 3V3 [pin 46] - 4_ [pin 6] - 40_ [pin 32] - 41_ [pin 33] - 5_ [pin 7] - 5V [pin 48] - 6_ [pin 8] - 7_ [pin 9] - 8_ [pin 10] - 9_ [pin 11] - G_1 [pin 1] - G_2 [pin 34] - G_3 [pin 47] ### U2 — [SGTL5000XNLA3](https://www.flux.ai/lcsc/sgtl5000xnla3~1t1d.md) - LCSC Part Number: C2802658 - Part Type: Codec ICs - Package or Case Code: QFN-20_L3.0-W3.0-P0.40-BL-EP1.7 - Manufacturer Part Number: SGTL5000XNLA3 - Role Details: SGTL5000 stereo audio codec for line-level stereo input/output and I2S/I2C interface to Teensy 4.1; replacement selected to resolve footprint copper overlap. - Role: Audio Codec - Datasheet URL: https://www.nxp.com/docs/en/data-sheet/SGTL5000.pdf - Manufacturer Name: NXP(恩智浦) - JLCPCB Part Class: Extended Part **Pins:** - CTRL_CLK [pin 19] - CTRL_DATA [pin 18] - EP [pin 21] - HP_L [pin 4] - HP_R [pin 1] - HP_VGND [pin 2] - I2S_DIN [pin 17] - I2S_DOUT [pin 16] - I2S_LRCLK [pin 14] - I2S_SCLK [pin 15] - LINEIN_L [pin 9] - LINEIN_R [pin 8] - LINEOUT_L [pin 7] - LINEOUT_R [pin 6] - MIC [pin 10] - MIC_BIAS [pin 11] - SYS_MCLK [pin 13] - VAG [pin 5] - VDDA [pin 3] - VDDD [pin 20] - VDDIO [pin 12] ### U3 — [MCP23017T-E/SO](https://www.flux.ai/adrian95/mcp23017t-eso~yix.md) - Manufacturer Part Number: MCP23017T-E/SO - Manufacturer Name: Microchip Technology - Part Type: Integrated Circuit - Role: I/O Expansion - Role Details: Scans track/global buttons over I2C using 3.3V logic. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP23017-Data-Sheet-DS20001952.pdf **Pins:** - ~RESET~ [pin 18] - A0 [pin 15] - A1 [pin 16] - A2 [pin 17] - GPA0 [pin 21] - GPA1 [pin 22] - GPA2 [pin 23] - GPA3 [pin 24] - GPA4 [pin 25] - GPA5 [pin 26] - GPA6 [pin 27] - GPA7 [pin 28] - GPB0 [pin 1] - GPB1 [pin 2] - GPB2 [pin 3] - GPB3 [pin 4] - GPB4 [pin 5] - GPB5 [pin 6] - GPB6 [pin 7] - GPB7 [pin 8] - INTA [pin 20] - INTB [pin 19] - NC [pin 11] - NC [pin 14] - SCK [pin 12] - SDA [pin 13] - VDD [pin 9] - VSS [pin 10] ### U4 — [CD74HC595M96](https://www.flux.ai/jecstronic/cd74hc595m96~uyk.md) - Datasheet URL: https://www.ti.com/lit/ds/symlink/cd74hc595.pdf - Manufacturer Part Number: CD74HC595M96 - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Texas Instruments - Role Details: Cascaded 74HC595 shift registers drive LED indicators through series resistors. - Role: LED Driver - Part Type: Integrated Circuit **Pins:** - GND [pin 8] - OE [pin 13] - QA [pin 15] - QB [pin 1] - QC [pin 2] - QD [pin 3] - QE [pin 4] - QF [pin 5] - QG [pin 6] - QH [pin 7] - QH¶ [pin 9] - RCLK [pin 12] - SER [pin 14] - SRCLK [pin 11] - SRCLR [pin 10] - VCC [pin 16] ### U5 — [CD74HC595M96](https://www.flux.ai/jecstronic/cd74hc595m96~uyk.md) - Part Type: Integrated Circuit - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Texas Instruments - Manufacturer Part Number: CD74HC595M96 - Role Details: Cascaded 74HC595 shift registers drive LED indicators through series resistors. - Role: LED Driver - Datasheet URL: https://www.ti.com/lit/ds/symlink/cd74hc595.pdf **Pins:** - GND [pin 8] - OE [pin 13] - QA [pin 15] - QB [pin 1] - QC [pin 2] - QD [pin 3] - QE [pin 4] - QF [pin 5] - QG [pin 6] - QH [pin 7] - QH¶ [pin 9] - RCLK [pin 12] - SER [pin 14] - SRCLK [pin 11] - SRCLR [pin 10] - VCC [pin 16] ### U6 — [TPS76301](https://www.flux.ai/kicad-part-library/tps76301~9n.md) - Manufacturer Part Number: TPS76301 - Package or Case Code: SOT-23-5 - Datasheet URL: http://www.ti.com/lit/ds/symlink/tps763.pdf - Manufacturer Name: Texas Instruments Inc. - Role: Power Conversion - Role Details: Generates 1.8V codec VDDD rail from 3.3V; SGTL5000 VDDD load is ~11mA, well below TPS76301 150mA rating; divider is R18=88.7kΩ/R19=169kΩ. **Pins:** - EN [pin 3] - FB [pin 4] - GND [pin 2] - VIN [pin 1] - VOUT [pin 5] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/chrubble/teensy-4-track-audio-looper~04](https://www.flux.ai/chrubble/teensy-4-track-audio-looper~04).* --- *Generated from [https://www.flux.ai/chrubble/teensy-4-track-audio-looper~04](https://www.flux.ai/chrubble/teensy-4-track-audio-looper~04)*