# pocket-soudbox
## Description
Pocket Soundbox – LiPo-Powered Cellular I2S MP3 Audio Player (SIMCom A7670E-LASE, Nano-SIM, I2S MP3 to PCM5101A DAC, FM8002E Amp, 1.8V↔3.3V UART/PWRKEY Level Shifting, Remapped J4, MP2315 3.3V Power Path, USB-C ESD/TVS) with power ON/OFF long-press control via SW2 and Q2 featuring pull-ups, RC debounce, and PFET safety clamp (#Cellular #I2S #LiPo #Audio #powerbutton #debounce #PFET)
## Project Details
- **Owner:** sayurun
- **Created:** 12/10/2025
- **Last Updated:** 12/11/2025
- **Visibility:** Public
- **Connectivity:** Cellular
- **Power Requirements:** USB
- **ConnectorNetAudit:** J2:P1 -> [BAT_OUT]
J2:P2 -> [GND]
J6:P1 -> [USIM1_VDD]
J6:P2 -> [USIM1_CLK]
J6:P3 -> [USIM1_DATA]
J6:P4 -> [USIM1_RST]
J6:P5 -> [USIM1_DET]
J6:P6 -> [GND]
- **System Architecture:** flowchart TD
Power[Power Subsystem]
USBC[USB-C Interface]
AO4407A[AO4407A MOSFET]
SIMCOM[SIMCom A7670E-LASE]
NanoSIM[Nano-SIM Socket]
LevelShifter[Level Shifter\n1.8V↔3.3V]
J4[External Connector J4]
SPIFlash[W25Q64JVSSIQ]
MP3Decoder[I2S MP3 Decoder]
PCM5101A[PCM5101A]
FM8002E[FM8002E]
USBC --> Power
USBC --> LevelShifter
Power --> AO4407A
AO4407A --> SIMCOM
SIMCOM --> NanoSIM
SIMCOM --> LevelShifter
LevelShifter --> J4
Power --> SPIFlash
SPIFlash --> MP3Decoder
Power --> MP3Decoder
MP3Decoder --> PCM5101A
Power --> PCM5101A
PCM5101A --> FM8002E
Power --> FM8002E
- **Domain:** Consumer Electronics
- **License:** http://solderpad.org/licenses/SHL-2.1/
- **Project Name:** Pocket Soundbox – LiPo-Powered Cellular I2S MP3 Audio Player
- **Software:** Arduino
- **SIM Connector Change Log:** Renamed Nano-SIM socket from J2 to J6; kept LiPo connector as J2; reconnected U1 USIM1_VDD/CLK/DATA/RST/DET and GND to J6 VCC/CLK/IO/RST/DET/GND via protection and pull network, leaving USB-C ESD/TVS (D1, D2) unchanged.
## Key Components
### — [100nF0603](https://www.flux.ai/charleszard/100nf0603~2x.md)
- Capacitance: 100nF
- Substitute Manufacturer Part Number: C1591
- Package or Case Code: C_0603_1608Metric
- Tolerance: 10%
- Package: SMD_0603_1608Metric
- Role: Debouncing
- Voltage: 50V
- Manufacturer Part Number: CL10B104KB8NNNC
- Role Details: Debounce capacitor for part SW3, pin 1, and part SW4, pin 1
**Pins:**
- ~ [pin 1]
- ~ [pin 2]
### — [100nF0603](https://www.flux.ai/charleszard/100nf0603~2x.md)
- Tolerance: 10%
- Role Details: Debounce capacitor for part SW3, pin 1, and part SW4, pin 1
- Package or Case Code: C_0603_1608Metric
- Substitute Manufacturer Part Number: C1591
- Capacitance: 100nF
- Package: SMD_0603_1608Metric
- Manufacturer Part Number: CL10B104KB8NNNC
- Role: Debouncing
- Voltage: 50V
**Pins:**
- ~ [pin 1]
- ~ [pin 2]
### D — [AO4407A](https://www.flux.ai/jecstronic/ao4407a~yc0.md)
- Manufacturer Name: Alpha & Omega Semiconductor Inc.
- Datasheet URL: http://www.aosmd.com/res/data_sheets/AO4407A.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Transistor
- Manufacturer Part Number: AO4407A
**Pins:**
- D [pin 5]
- D [pin 7]
- D [pin 8]
- D [pin 6]
- G [pin 4]
- S [pin 2]
- S [pin 3]
- S [pin 1]
### D1 — [SMBJ5.0CA-TR](https://www.flux.ai/lcsc/smbj5p0ca-tr~dop2.md)
- Part Type: TVS
- LCSC Part Number: C133658
- Manufacturer Name: ST(意法半导体)
- Manufacturer Part Number: SMBJ5.0CA-TR
- Package or Case Code: SMB_L4.6-W3.6-LS5.3-BI
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_STMicroelectronics-SMBJ5-0CA-TR_C133658.pdf
- Product Info Url: https://lcsc.com/product-detail/TVS_STMicroelectronics_SMBJ5-0CA-TR_SMBJ5-0CA-TR_C133658.html
- JLCPCB Part Class: Extended Part
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D2 — [SMF05CT2G](https://www.flux.ai/lcsc/smf05ct2g~mihw.md)
- LCSC Part Number: C513065
- Product Info Url: https://lcsc.com/product-detail/Diodes-ESD_ON-Semiconductor-ON-SMF05CT2G_C513065.html
- Part Type: ESD Protection Devices
- JLCPCB Part Class: Extended Part
- Package: SC-88-6_L2.0-W1.3-P0.65-LS2.1-BR
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2004241933_onsemi-SMF05CT2G_C513065.pdf
- Role: Protection
- Manufacturer Part Number: SMF05CT2G
- Role Details: ESD protection for USB D+ and D–
- Manufacturer Name: onsemi(安森美)
- Package or Case Code: SC-88-6_L2.0-W1.3-P0.65-LS2.1-BR
**Pins:**
- A [pin 2]
- C1 [pin 1]
- C2 [pin 3]
- C3 [pin 4]
- C4 [pin 5]
- C5 [pin 6]
### D4 — [SMF05CT2G](https://www.flux.ai/lcsc/smf05ct2g~mihw.md)
- JLCPCB Part Class: Extended Part
- Part Type: ESD Protection Devices
- LCSC Part Number: C513065
- Product Info Url: https://lcsc.com/product-detail/Diodes-ESD_ON-Semiconductor-ON-SMF05CT2G_C513065.html
- Role Details: ESD protection for SIM interface at J6
- Manufacturer Part Number: SMF05CT2G
- Role: Protection
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2004241933_onsemi-SMF05CT2G_C513065.pdf
- Manufacturer Name: onsemi(安森美)
- Package or Case Code: SC-88-6_L2.0-W1.3-P0.65-LS2.1-BR
**Pins:**
- A [pin 2]
- C1 [pin 1]
- C2 [pin 3]
- C3 [pin 4]
- C4 [pin 5]
- C5 [pin 6]
### DZ1 — [PZU7.5BA,115](https://www.flux.ai/lcsc/pzu7p5bac115~qm1c.md)
- Package or Case Code: SOD-323_L1.8-W1.3-LS2.5-RD
- Part Type: Zener Diodes
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407251004_Nexperia-PZU7-5BA-115_C553789.pdf
- Manufacturer Part Number: PZU7.5BA,115
- Package: SOD-323_L1.8-W1.3-LS2.5-RD
- Product Info Url: https://lcsc.com/product-detail/presales_Nexperia-PZU7-5BA-115_C553789.html
- Manufacturer Name: Nexperia(安世)
- Role Details: Gate clamp for PFET AO4407A gate to source
- JLCPCB Part Class: Extended Part
- Role: Protection
- LCSC Part Number: C553789
**Pins:**
- A [pin 2]
- K [pin 1]
### IC1 — [PCM5101AQPWRQ1](https://www.flux.ai/adrian95/pcm5101aqpwrq1~qev.md)
- Manufacturer Name: Texas Instruments
- Part Type: Integrated Circuit
- Manufacturer Part Number: PCM5101AQPWRQ1
- Package or Case Code: SOP65P640X120-20N
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: http://www.ti.com/lit/gpn/pcm5101a-q1
**Pins:**
- AGND [pin 9]
- AVDD [pin 8]
- BCK [pin 13]
- CAPM [pin 4]
- CAPP [pin 2]
- CPGND [pin 3]
- CPVDD [pin 1]
- DEMP [pin 10]
- DGND [pin 19]
- DIN [pin 14]
- DVDD [pin 20]
- FLT [pin 11]
- FMT [pin 16]
- LDOO [pin 18]
- LRCK [pin 15]
- OUTL [pin 6]
- OUTR [pin 7]
- SCK [pin 12]
- VNEG [pin 5]
- XSMT [pin 17]
### J1 — [Type-C-2.0-6Pin](https://www.flux.ai/jharwinbarrozo/type-c-2p0-6pin~wh.md)
- Part Type: Connector
- Manufacturer Part Number: Type-C-2.0-6Pin
- Datasheet URL: https://datasheet.lcsc.com/lcsc/2204071830_CIKI-Type-C-2-0-6Pin_C2987385.pdf
- Manufacturer Name: CIKI
**Pins:**
- CC1
- CC2
- GND
- GND__1
- SHIELD
- SHIELD__1
- SHIELD__2
- SHIELD__3
- V-BUS
- V-BUS__1
### J2 — [S2B-PH-K-S(LF)(SN)](https://www.flux.ai/adrian95/s2b-ph-k-slfsn~brb.md)
- Part Type: Connector
- Manufacturer Name: JST Sales America Inc.
- Manufacturer Part Number: S2B-PH-K-S(LF)(SN)
- Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- P1 [pin 1]
- P2 [pin 2]
### J3 — [S2B-PH-K-S(LF)(SN)](https://www.flux.ai/adrian95/s2b-ph-k-slfsn~brb.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf
- Manufacturer Name: JST Sales America Inc.
- Manufacturer Part Number: S2B-PH-K-S(LF)(SN)
- Part Type: Connector
**Pins:**
- P1 [pin 1]
- P2 [pin 2]
### J4 — [Pin Header 02x04 2.54mm Vertical SMD](https://www.flux.ai/tyler-s/pin-header-02x04-2p54mm-vertical-smd~zb.md)
- Datasheet URL: https://cdn.amphenol-cs.com/media/wysiwyg/files/drawing/10129383.pdf
- Manufacturer Name: Amphenol
- Part Type: Connector
- Manufacturer Part Number: 10129383-908001ALF
**Pins:**
- P1
- P2
- P3
- P4
- P5
- P6
- P7
- P8
### J5 — [Pin Header 01x06 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-01x06-2p54mm-vertical~lzd.md)
- Role: Connector
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: SPI Flash access header for U2 (CS, CLK, IO0–IO3, 3V3, GND)
**Pins:**
- Pin_1 [pin 1]
- Pin_2 [pin 2]
- Pin_3 [pin 3]
- Pin_4 [pin 4]
- Pin_5 [pin 5]
- Pin_6 [pin 6]
### J6 — [SIM8051-6-0-14-00-A](https://www.flux.ai/jecstronic/sim8051-6-0-14-00-a~7b7.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: Nano-SIM card socket for cellular module
- Manufacturer Part Number: SIM8051-6-0-14-00-A
- Part Type: Connector
- Role: Connector
- Datasheet URL: https://media.digikey.com/pdf/Data%20Sheets/GCT%20PDFs/SIM8051_Spec.pdf
- Manufacturer Name: GCT
**Pins:**
- CLK [pin C3]
- GND [pin C5]
- I/O [pin C7]
- RST [pin C2]
- VCC [pin C1]
- VPP [pin C6]
### LED1 — [LED-0805-Template](https://www.flux.ai/vasy_skral/led-0805-template~dfa.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
**Pins:**
- A [pin 2]
- K [pin 1]
### LED2 — [LED-0805-Template](https://www.flux.ai/vasy_skral/led-0805-template~dfa.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
**Pins:**
- A [pin 2]
- K [pin 1]
### Q2 — [2N7002](https://www.flux.ai/lcsc/2n7002~13ip.md)
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/MOSFET_MDD-Microdiode-Electronics-2N7002_C472906.html
- Package or Case Code: SOT-23-3_L2.9-W1.5-P1.90-LS2.6-BR
- Part Type: MOSFETs
- Role Details: Soft-latch MOSFET for AO4407A gate control
- Transistor Type: N-channel MOSFET
- Drain to Source Voltage: 60V
- Continuous Drain Current: 200mA at 25°C
- Role: Switching
- Manufacturer Part Number: 2N7002
- Package: SOT-23-3_L2.9-W1.5-P1.90-LS2.6-BR
- LCSC Part Number: C472906
- Manufacturer Name: MDD(辰达半导体)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407101108_MDD-Microdiode-Semiconductor-2N7002_C472906.pdf
**Pins:**
- D [pin 3]
- G [pin 1]
- S [pin 2]
### SW2 — [B3U-3000P](https://www.flux.ai/adrian95/b3u-3000p~l3s.md)
- Manufacturer Name: Omron Electronics Inc-EMC Div
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3u.pdf
- Part Type: Switch
- Manufacturer Part Number: B3U-3000P
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### SW3 — [B3U-3000P](https://www.flux.ai/adrian95/b3u-3000p~l3s.md)
- Part Type: Switch
- Manufacturer Part Number: B3U-3000P
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: Omron Electronics Inc-EMC Div
- Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3u.pdf
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### SW4 — [B3U-3000P](https://www.flux.ai/adrian95/b3u-3000p~l3s.md)
- Manufacturer Part Number: B3U-3000P
- Part Type: Switch
- Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3u.pdf
- Manufacturer Name: Omron Electronics Inc-EMC Div
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### U? — [VS1053B-L](https://www.flux.ai/jecstronic/vs1053b-l~bo9.md)
- Role: Modulation / Demodulation
- Manufacturer Part Number: VS1053B-L
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1809050216_VLSI-Solution-VS1053B-L_C9922.pdf
- Manufacturer Name: VLSI Solution
- Package: LQFP-48
- Role Details: MP3 decoder, I2S output to PCM5101A
- Part Type: Integrated Circuit
**Pins:**
- ~CS~ [pin 23]
- ~DCS~/BSYNC [pin 13]
- ~RESET~ [pin 3]
- ~TEST~ [pin 32]
- AGND0 [pin 37]
- AGND1 [pin 40]
- AGND2 [pin 41]
- AGND3 [pin 47]
- AVDD0 [pin 38]
- AVDD1 [pin 43]
- AVDD2 [pin 45]
- CVDD0 [pin 5]
- CVDD1 [pin 7]
- CVDD2 [pin 24]
- CVDD3 [pin 31]
- DGND0 [pin 4]
- DGND1 [pin 16]
- DGND2 [pin 20]
- DGND3 [pin 21]
- DGND4 [pin 22]
- DREQ [pin 8]
- GBUF [pin 42]
- GND [pin 35]
- GPIO0 [pin 33]
- GPIO1 [pin 34]
- GPIO2/DCLK [pin 9]
- GPIO3/SDATA [pin 10]
- GPIO4/I2S_LROUT [pin 36]
- GPIO5/I2S_MCLK [pin 25]
- GPIO6/I2S_SCLK [pin 11]
- GPIO7/I2S_SDATA [pin 12]
- IOVDD0 [pin 6]
- IOVDD1 [pin 14]
- IOVDD2 [pin 19]
- LEFT [pin 46]
- LINE2 [pin 48]
- MICN [pin 2]
- MICP/LINE1 [pin 1]
- RCAP [pin 44]
- RIGHT [pin 39]
- RX [pin 26]
- SCLK [pin 28]
- SI [pin 29]
- SO [pin 30]
- TX [pin 27]
- VCO [pin 15]
- XTALI [pin 18]
- XTALO [pin 17]
### U1 — [A7670C-LASE](https://www.flux.ai/lcsc/a7670c-lase~cbwy.md)
- LCSC Part Number: C2888406
- Package or Case Code: LGA-124_L24.0-W24.0-P1.0-A7670C-LASS
- Role Details: Main cellular module with I2C/SPI/UART interfaces
- Role: Cellular Modem
- JLCPCB Part Class: Extended Part
- Manufacturer Name: SIMCOM(芯讯通无线科技)
- Manufacturer Part Number: A7670C-LASE
**Pins:**
- 1PPS [pin 100]
- 1V8_GNSS [pin 97]
- ADC [pin 25]
- AP_WAKEUP [pin 3]
- BT_ANT [pin 93]
- EAR_N [pin 41]
- EAR_P [pin 40]
- GND [pin 17]
- GND [pin 29]
- GND [pin 39]
- GND [pin 45]
- GND [pin 59]
- GND [pin 61]
- GND [pin 63]
- GND [pin 65]
- GND [pin 69]
- GND [pin 71]
- GND [pin 73]
- GND [pin 75]
- GND [pin 77]
- GND [pin 79]
- GND [pin 81]
- GND [pin 83]
- GND [pin 85]
- GND [pin 87]
- GND [pin 89]
- GND [pin 91]
- GND [pin 2]
- GND [pin 18]
- GND [pin 46]
- GND [pin 54]
- GND [pin 58]
- GND [pin 62]
- GND [pin 64]
- GND [pin 70]
- GND [pin 72]
- GND [pin 74]
- GND [pin 76]
- GND [pin 78]
- GND [pin 80]
- GND [pin 82]
- GND [pin 84]
- GND [pin 86]
- GND [pin 88]
- GND [pin 92]
- GND [pin 94]
- GNSS_ANT [pin 90]
- GNSS_PWR_EN/MK_IN_3 [pin 20]
- GNSS_PWRCTL [pin 98]
- GNSS_RXD [pin 96]
- GNSS_TXD [pin 95]
- GNSS_VBKP [pin 116]
- GPIO_00 [pin 4]
- GPIO_01 [pin 5]
- GPIO_02 [pin 6]
- GPIO_03 [pin 7]
- GPIO_04 [pin 8]
- GPIO_05 [pin 19]
- GPIO_07/MK_OUT_3 [pin 21]
- GPIO_08 [pin 48]
- GPIO_09 [pin 52]
- GPIO_10 [pin 66]
- GPIO_11/MK_OUT_5 [pin 67]
- GPIO_12/MK_IN_5 [pin 68]
- GPIO_13/MK_OUT_6 [pin 35]
- GPIO_14/MK_IN_6 [pin 36]
- GPIO_15/MK_OUT_2 [pin 44]
- GPIO_16/MK_IN_2 [pin 47]
- GPIO_17 [pin 26]
- GPIO_18 [pin 53]
- GPIO_19/LCD_BL_PWM [pin 101]
- GPIO_20/LCD_SPI_CLK [pin 102]
- GPIO_21/LCD_SPI_TXD [pin 103]
- GPIO_22/LCD_SPI_RXD [pin 104]
- GPIO_23/LCD_SPI_CS [pin 105]
- GPIO_24/LCD_RST [pin 106]
- GPIO_25/LCD_DCX [pin 107]
- GPIO_26 [pin 117]
- GPIO_27 [pin 118]
- GPIO_28 [pin 119]
- GPIO_29 [pin 120]
- GPIO_30 [pin 121]
- GPIO_31 [pin 122]
- GPIO_32 [pin 123]
- GPIO_33 [pin 124]
- I2C_SCL [pin 38]
- I2C_SDA [pin 37]
- MIC_N [pin 43]
- MIC_P [pin 42]
- NC [pin 113]
- NC [pin 115]
- NC [pin 114]
- PWRKEY [pin 1]
- RESET [pin 16]
- RF_ANT [pin 60]
- RXD [pin 10]
- SPI_CLK [pin 11]
- SPI_CS [pin 12]
- SPI_MISO [pin 14]
- SPI_MOSI [pin 13]
- TXD [pin 9]
- UART_LOG_RX [pin 22]
- UART_LOG_TX [pin 23]
- UART3_RXD [pin 49]
- UART3_TXD [pin 50]
- USB_DM [pin 28]
- USB_DP [pin 27]
- USIM1_CLK [pin 32]
- USIM1_DATA [pin 31]
- USIM1_DET [pin 34]
- USIM1_RST [pin 33]
- USIM1_VDD [pin 30]
- USIM2_CLK [pin 109]
- USIM2_DATA [pin 108]
- USIM2_DET [pin 112]
- USIM2_RST [pin 111]
- USIM2_VDD [pin 110]
- VBAT [pin 55]
- VBAT [pin 57]
- VBAT [pin 56]
- VBAT_ADC [pin 51]
- VBUS [pin 24]
- VDD_1V8 [pin 15]
- VDD_2V8 [pin 99]
### U2 — [W25Q64JVSSIQ](https://www.flux.ai/lcsc/w25q64jvssiq~ias3.md)
- Frequency: 133MHz
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1912211532_Winbond-Elec-W25Q64JVSSIQ_C179171.pdf
- Voltage Supply: 2.7 ~ 3.6V
- JLCPCB Part Class: Extended Part
- Manufacturer Name: WINBOND(华邦)
- Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Winbond-Elec-W25Q64JVSSIQ_C179171.html
- LCSC Part Number: C179171
- Package or Case Code: SOIC-8_L5.3-W5.3-P1.27-LS8.0-BL
- Part Type: NOR FLASH
- Operating Temperature: -40°C ~ 85°C (TA)
- Manufacturer Part Number: W25Q64JVSSIQ
**Pins:**
- ~{CS} [pin 1]
- CLK [pin 6]
- DI(IO0) [pin 5]
- DO(IO1) [pin 2]
- GND [pin 4]
- HOLD#orRESET#(IO3) [pin 7]
- VCC [pin 8]
- WP#(IO2) [pin 3]
### U3 — [FM8002E](https://www.flux.ai/lcsc/fm8002e~6ft0.md)
- Package or Case Code: SOP-8_L4.9-W3.9-P1.27-LS6.0-BL
- Product Info Url: https://lcsc.com/product-detail/Others_Shenzhen-Fuman-Elec-FM8002E_C340921.html
- Manufacturer Name: FM(富满)
- Manufacturer Part Number: FM8002E
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2202251530_Shenzhen-Fuman-Elec-FM8002E_C340921.pdf
- Part Type: Audio Power OpAmps
- LCSC Part Number: C340921
**Pins:**
- -IN [pin 4]
- +IN [pin 3]
- BYPASS [pin 2]
- GND [pin 7]
- SHUTDOWN [pin 1]
- VDD [pin 6]
- VO1 [pin 5]
- VO2 [pin 8]
### U4 — [SLM6400](https://www.flux.ai/lcsc/slm6400~bgrf.md)
- JLCPCB Part Class: Extended Part
- Manufacturer Name: 无锡松朗微
- Package or Case Code: DFN-8_L3.0-W3.0-P0.65-BL-EP
- LCSC Part Number: C338664
- Product Info Url: https://lcsc.com/product-detail/Others_SOLA-IC-SLM6400_C338664.html
- Part Type: Battery Management ICs
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2007231614_SOLA-IC-SLM6400_C338664.pdf
- Manufacturer Part Number: SLM6400
**Pins:**
- BAT [pin 5]
- EP [pin 9]
- GND [pin 3]
- NCE [pin 8]
- NCH [pin 7]
- NPG [pin 6]
- NTC [pin 1]
- PROG [pin 2]
- VCC [pin 4]
### U5 — [MP2315SGJ](https://www.flux.ai/monolithicpower/mp2315sgj~lcs.md)
- Manufacturer Name: Monolithic Power Systems
- Product Info Url: https://www.monolithicpower.com/en/catalog/product/view/id/1078?utm_source=ultralibrarian&utm_medium=component_search&utm_campaign=listing
- Package or Case Code: TSOT23-8_MP2315S_MNP
- Datasheet URL: https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP2315S
- Product Image Url: https://www.monolithicpower.com/pub/media/catalog/product/M/P/MP2315S_1078_1.jpg
- Manufacturer Part Number: MP2315SGJ
**Pins:**
- AAM [pin 1]
- BST [pin 5]
- EN [pin 6]
- FB [pin 8]
- GND [pin 4]
- IN [pin 2]
- SW [pin 3]
- VCC [pin 7]
### U6 — [SN74LVC2T45DCTT](https://www.flux.ai/lcsc/sn74lvc2t45dctt~xmz.md)
- Package or Case Code: SSOP-8_L3.1-W2.8-P0.65-LS4.0-BL
- Manufacturer Part Number: SN74LVC2T45DCTT
- Part Type: Translators / Level Shifters
- Manufacturer Name: TI(德州仪器)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010103_Texas-Instruments-SN74LVC2T45DCTT_C347590.pdf
- LCSC Part Number: C347590
- Role Details: 1.8V↔3.3V level shifting for UART TX/RX and PWRKEY signals
- JLCPCB Part Class: Extended Part
- Role: Logic-level Shifting
- Product Info Url: https://lcsc.com/product-detail/Others_Texas-Instruments-TI-SN74LVC2T45DCTT_C347590.html
- Package: SSOP-8_L3.1-W2.8-P0.65-LS4.0-BL
**Pins:**
- A1 [pin 2]
- A2 [pin 3]
- B1 [pin 7]
- B2 [pin 6]
- DIR [pin 5]
- GND [pin 4]
- VCCA [pin 1]
- VCCB [pin 8]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/sayurun/pocket-soudbox~u2](https://www.flux.ai/sayurun/pocket-soudbox~u2).*
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*Generated from [https://www.flux.ai/sayurun/pocket-soudbox~u2](https://www.flux.ai/sayurun/pocket-soudbox~u2)*