SF32LB58x Hardware Design Checklist¶

1. Introduction¶

This checklist is the complete schematic and PCB review reference for products based on the SF32LB58x family. It is derived from SiFli's official SF32LB58x Schematic & PCB Checklist workbook (V1.0, 2026-01-21) and keeps the source workbook order, row numbering, applicability, Required/Optional status, and review highlighting.

Use it as the formal design-review gate: complete the schematic checklist before PCB layout starts, then complete the PCB layout checklist before Gerber release. For release review, keep a filled copy with both the initial-review and follow-up-review results.

Colored text and text with a yellow background preserve the review emphasis from the source spreadsheet. The workbook does not explain the reason for each highlight, so treat these marks as additional review flags.

2. Review Record¶

Table 2-1: Review Record Template

Field	Value
Customer name
Customer design name
Submission date for review
Initial reviewer
Initial review date
Follow-up reviewer
Follow-up review date

Table 2-2: Document Version History

No.	Version	Date	Release Notes
1	V1.0	2026-01-21	Initial release of the Schematic & PCB Checklist document

3. Schematic Checklist¶

Each table below covers one schematic functional block. Apply a row only to the variants listed in the Applies To column when that column is present.

3.1. Package¶

Table 3.1-1: Package Checklist

No.	Check Point	Category
1	The package of the selected part number is correct, including pin names and pin numbers	Required

3.2. Power Supply¶

Table 3.2-1: Power Supply Checklist

No.	Check Point	Category
1	PVDD1 supply voltage is 1.8 V-3.3 V	Required
2	PVDD2 supply voltage is 1.8 V-3.3 V	Required
3	BUCK1_LX and BUCK1_FB connections are correct	Required
4	BUCK2_LX and BUCK2_FB connections are correct	Required
5	LDO_VOUT1 output has a test point, or a filter capacitor convenient for voltage measurement	Required
6	VDD_RET output has a test point, or a filter capacitor convenient for voltage measurement	Required
7	VDD_RTC output has a test point, or a filter capacitor convenient for voltage measurement	Required
8	VDDIOA supply voltage is 1.8 V-3.3 V; reserve a 0 Ω series resistor in the first board revision	Required
9	VDDIOA2 supply voltage is 1.8 V-3.3 V; reserve a 0 Ω series resistor in the first board revision	Required
10	VDDIOB supply voltage is 1.8 V-3.3 V; reserve a 0 Ω series resistor in the first board revision	Required
11	VDDIOSA supply voltage is 1.8 V, and a load switch is provided so it can be shut off	Required
12	VDDIOSB supply voltage is 1.8 V, and a load switch is provided so it can be shut off	Required
13	VDDIOSC supply voltage is 1.8 V and must always be powered	Required
14	AVDD33_USB supply voltage is 3.3 V	Required
15	AVDD33_ANA supply voltage is 3.3 V	Required
16	AVDD_BRF supply voltage is 1.8 V-3.3 V and must match the VDD1 supply	Required
17	AVDD33_AUD supply voltage is 3.3 V	Required
18	AVDD18_DSI supply voltage is 1.8 V	Required
19	When SF30147C supplies power, the TWI control interface must use MCU PB pins, and those pins must be PD pins	Required
20	Charging circuit requires path management so the system can be powered from the charger 5 V input when battery voltage is too low	Required
21	When SF30147C supplies power, use the chip-dedicated TWI control interface	Required
22	When SF30147C supplies power, rails controlled by EN must use PVDD or AVDD as the EN power domain; do not control EN from an MCU GPIO. Alternatively, tie EN to ground and control the corresponding rail output through registers	Required
23	When SF30147C supplies power, BUCK and LDO1 can only be controlled by their respective enable signals, EN_BUCK and EN_LDO1; internal register control is not provided	Required
24	58x PVDD and VDDIOB supplies must match. If PVDD is lower than VDDIOB, for example VDDIOB = 3.3 V and PVDD = 1.8 V, VDDIOB has about 15 uA leakage in Standby and Hibernate	Required
25	On 58x, pin B4 is VDD_EXT1 and pin B5 is VDD_EXT2; they may be left unconnected in the design	Required

3.3. Power Supply Capacitors and Inductors¶

Table 3.3-1: Power Supply Capacitors and Inductors Checklist

No.	Check Point	Category
1	PVDD1 bulk capacitor is at least 10 uF	Required
2	PVDD2 capacitor is at least 10 uF	Required
3	BUCK1_FB capacitor=4.7u	Required
4	BUCK2_FB capacitor=4.7u	Required
5	LDO_VOUT1 capacitor=4.7u	Required
6	VDD_RET capacitor=0.47u	Required
7	VDD_RTC capacitor=1u	Required
8	VDDIOA capacitor>=1u	Required
9	VDDIOA2 capacitor>=1u	Required
10	VDDIOB capacitor>=1u	Required
11	VDDIOSA capacitor>=1u	Required
12	VDDIOSB capacitor>=1u	Required
13	VDDIOSC capacitor>=1u	Required
14	AVDD33_USB capacitor>=1u	Required
15	AVDD33_ANA capacitor>=4.7u	Required
16	AVDD_BRF capacitor>=4.7u	Required
17	AVDD33_AUD capacitor>=4.7u	Required
18	AUD_VREF capacitor=1u	Required
19	AVDD18_DSI capacitor>=4.7u	Required
20	MIC_BIAS capacitor=1u	Required
21	GPADC VREFP capacitor = 4.7 uF	Required
22	PVDD1, PVDD2, AVDD_BRF, and the RSTN pull-up supply must be the same	Required
23	BUCK1 and BUCK2 inductors are SiFli-recommended part numbers	Required
24	If the BUCK inductor is not SiFli-recommended, it meets L = 4.7 uH, DCR <= 0.4 ohm, and Isat >= 450 mA	Required
25	When PVDD1 and PVDD2 are powered at 1.8 V from VBAT, use a DCDC converter to generate 1.8 V; do not use an LDO	Required
26	Quiescent current of the selected DCDC is recorded and meets project requirements	Required
27	Quiescent current of the selected LDO is recorded and meets project requirements	Required

3.4. Clock¶

Table 3.4-1: Clock Checklist

No.	Check Point	Category
1	Main 48 MHz crystal is an AVL-listed part number	Required
2	If the 48 MHz crystal is not AVL-listed, it meets 7 pF ≤ CL ≤ 12 pF (8.8 pF recommended), frequency tolerance ≤±10 ppm, ESR ≤30 Ω (22 Ω recommended)	Required
3	RTC 32.768 kHz crystal is an AVL-listed part number	Required
4	If the 32.768 kHz crystal is not AVL-listed, it meets CL ≤12.5 pF (7 pF recommended), frequency tolerance ≤±20 ppm, ESR ≤80 kΩ (38 kΩ recommended)	Required

3.5. Reset¶

Table 3.5-1: Reset Checklist

No.	Check Point	Category
1	RSTN is pulled up to the same supply as PVDD1	Required
2	RSTN reserves a 0.1 uF capacitor to ground	Required
3	RSTN has ESD protection	Required

3.6. Ground Signals¶

Table 3.6-1: Ground Signals Checklist

No.	Check Point	Category
1	All AVSS_* signals are connected to GND	Required
2	All VSS signals are connected to GND	Required

3.7. Boot Mode¶

Table 3.7-1: Boot Mode Checklist

No.	Check Point	Category
1	MODE has an internal pull-down; reserve a 10 kΩ pull-up to VDDIOA and drive MODE high during program download	Required
2	MODE signal has a reserved test point and must be brought out to the production programming fixture	Required

3.8. RF¶

Table 3.8-1: RF Checklist

No.	Check Point	Category
1	The ANT signal is annotated with the single-ended 50 Ω characteristic-impedance requirement	Required
2	A Pi-type matching network is reserved on the ANT signal: a parallel NC (do-not-populate) capacitor and a 15 pF series capacitor	Required
3	If spurious-emission filtering must be considered, a Pi-type matching network is reserved with a 2.7 nH series inductor and a 2 pF parallel capacitor	Optional
4	If an external RF PA requires MCU control of RXEN and TXEN, use only PB39 for PA RXEN and PB40 for PA TXEN	Optional
5	If Wi-Fi chip supports antenna coexistence arbitration: (1) 3-wire mode is recommended: the Wi-Fi chip controls the Bluetooth/Wi-Fi antenna RF switch and performs arbitration. It uses BT_ACTIVE and BT_PRIORITY from Bluetooth to decide whether to grant antenna ownership to Bluetooth, and WLAN_ACTIVE can disable Bluetooth transmit/receive during Wi-Fi operation. (2)BT_ACTIVE must use PB08 or PB45, WLAN_ACTIVE must use PB09 or PB41, and BT_PRIORITY may use any PB GPIO.	Optional
6	If the Wi-Fi chip does not support antenna coexistence arbitration: (1) 1-wire mode is recommended, Bluetooth controls the Bluetooth/Wi-Fi antenna RF switch, performs arbitration using BT_ACTIVE, and notifies the Wi-Fi chip. (2) If Wi-Fi can output an operating-state signal, this scheme can be upgraded to 2-wire mode: connect the Wi-Fi output to WLAN_ACTIVE so Bluetooth can mask low-priority Bluetooth transmit/receive while Wi-Fi is active, without affecting Bluetooth when Wi-Fi is idle. (3)BT_ACTIVE must use PB08 or PB45, WLAN_ACTIVE must use PB09 or PB41	Optional

3.9. I/O Resource Allocation¶

Table 3.9-1: I/O Resource Allocation Checklist

No.	Check Point	Category
1	A GPIO resource-allocation table matching the schematic is provided	Required
2	The GPIO allocation in the resource table matches the schematic	Required
3	The actual GPIO allocation follows SiFli recommendations; refer to the EVB I/O config file	Required

3.10. Hardware Wake-up¶

Table 3.10-1: Hardware Wake-up Checklist

No.	Check Point	Category
1	HCPU wake-up interrupt sources are correct: PA64, PA65, PA66, PA67, PA68, and PA69, six pins total	Required
2	LCPU wake-up interrupt sources are correct: PB54, PB55, PB56, PB57, PB58, PB59, PBR0, PBR1, PBR2, and PBR3, ten pins total. After MCU wake-up, PBR0-PBR3 cannot receive interrupt signals	Required
3	Interrupt and control signals for LCPU-side peripherals such as G-sensor and heart-rate sensor must connect to PB GPIOs	Required

3.11. Storage¶

Table 3.11-1: Storage Checklist

No.	Check Point	Category
1	MPI3 is connected to NOR flash or SPI NAND flash as intended	Required
2	VDDIOSC is always powered	Required
3	VDDIOSA and VDDIOSB supplies are enabled by PBR0	Required
4	MPI3 or MPI4 may be used for external NOR flash or SPI NAND flash	Required
5	The SPI NAND flash HOLD# pin is pulled up to the SPI NAND flash supply through a 10 kΩ resistor	Required
6	If production needs to program external flash on MPI3 or MPI4, the download tool drives PA43 high to enable MPI3 power	Required
7	If production needs to program eMMC or SD NAND on SDIO1, the download tool enables the corresponding power supply	Required
8	PBR0/PA43-controlled voltage switches are active-high on and active-low off. In Hibernate, PBR0 controls VDDIOSA/VDDIOSB power switching, VDDIOSC remains always powered, and PA43 controls external flash power switching	Required
9	If the SD1 interface connects to eMMC or SD NAND, the signal connections are correct	Required
10	The eMMC or SD NAND I/O interface level matches VDDIOA2	Required
11	MPI3 or MPI4 signal connections are correct	Required
12	The peripheral device's I/O logic level matches the main chip's	Required
13	NOR flash is qualified in the key-component selection guide	Required
14	SPI/SD NAND flash is qualified in the key-component selection guide	Required
15	eMMC is qualified in the key-component selection guide	Required

3.12. Display¶

Table 3.12-1: Display Checklist

No.	Check Point	Category
1	SF32LB58x connects the display through DSI + LCDC2 as intended	Required
2	DSI signal connections are correct	Required
3	If only QSPI LCD is used, use the HCPU LCDC1 QSPI interface to avoid frame-rate and RAM issues	Required
4	DSI_REXT is connected to GND through a 10 kΩ resistor	Required
5	The LCDC RSTB connection is correct	Required
6	LCDC TE connection is correct (connects to the panel's TE or Fmark signal)	Required
7	TP signals follow the recommended pin assignment (refer to the EVB I/O config file)	Required
8	The LCD interface supports MIPI-DSI, 3-/4-wire SPI, dual/quad-data SPI, DBI 8080, DPI, and parallel/serial JDI interfaces	Required
9	SPI LCD, 3-wire mode: CS connected to PA44 or PB08, CLK connected to PA46 or PB10, DATA connected to PA50 or PB09; 4-wire mode: CS connected to PA44 or PB08, CLK connected to PA46 or PB10, DATA connected to PA50 or PB09, DC connected to PA48 or PB03	Required
10	Confirm whether the LCD must support AOD; if so, a QSPI panel must connect to HCPU, while a JDI panel may connect to LCPU	Required
11	The peripheral device's I/O logic level matches the main chip's	Required
12	For DSI LCDs, connect DSI data and clock signals. DSI video-mode panels behave like RGB panels and have no TE signal; DSI command-mode panels have a TE signal, and DSI17801 requires TE. TE and RST are both recommended; final usage depends on the selected LCD	Required

3.13. GPADC¶

Table 3.13-1: GPADC Checklist

No.	Check Point	Category
1	GPADC input is connected to the corresponding pin	Optional
2	GPADC input range is correct; maximum input voltage must not exceed AVDD33_AVA	Optional
3	Battery-voltage divider recommendation: 470 kΩ 1% resistor on the supply side, 1 MΩ 1% resistor to ground, and 100 nF filter capacitor	Required
4	For every resistor-divider signal measured by GPADC, use 1%-tolerance divider resistors; each GPADC channel must have a 100 nF filter capacitor placed close to the chip pin	Required
5	ADC can detect multiple buttons and save pins; for example, when PB32 is used as an ADC button, do not use the battery as the pull-up supply	Required

3.14. SDMADC¶

Table 3.14-1: SDMADC Checklist

No.	Check Point	Category
1	SDMADC input is connected to the corresponding pin	Optional
2	SDMADC input range is correct; maximum input voltage should not exceed AVDD33_AVA	Optional
3	SDMADC_VREF and SDMADC_VSS_VREF connections are correct	Required

3.15. Buttons¶

Table 3.15-1: Buttons Checklist

No.	Check Point	Category
1	Confirm with the customer whether the button requires wake-up capability	Required
2	Ordinary-button connection is correct (pull-up present, correct resistor value, correct pull-up voltage domain)	Required
3	Power button must use PB54, active-high, 10-second long-press reset, 10 kΩ pull-down resistor must be on the main board	Required
4	All button signals have ESD protection	Required

3.16. EOS and ESD Protection¶

Table 3.16-1: EOS and ESD Protection Checklist

No.	Check Point	Category
1	Charging interface has EOS, ESD, and OVP design	Required
2	Charger-insertion detection signal has an ESD device	Required
3	Battery interface has an ESD device	Required
4	Antenna interface has an ESD device	Required
5	LCD and TP power interfaces have ESD devices	Required
6	TP I2C, RST, and INT lines have ESD devices	Required
7	Heart-rate sensor power interface and signal lines have ESD devices	Required

3.17. I2C¶

Table 3.17-1: I2C Checklist

No.	Check Point	Category
1	I2C assignment accounts for HCPU/LCPU partitioning and whether the device must run in low-power mode	Required
2	I2C has pull-ups with the correct resistor value; if 400 kHz operation is required, 2.2 kΩ pull-ups are recommended. Use the peripheral-side voltage domain and shut the pull-up supply off with the peripheral at power-down	Required
3	I2C interrupt signal supports hardware wake-up where required	Required
4	If multiple devices share one I2C bus, their addresses are distinguished	Required

3.18. I2S¶

Table 3.18-1: I2S Checklist

No.	Check Point	Category
1	I2S1 is input-only and operates only in master mode; the microphone is connected to I2S1 as intended	Optional
2	I2S2 supports input and output in master mode only, and may connect to external codec DAC/ADC devices	Optional
3	I2S3 supports input and output in master mode only; it is suitable for low-power use cases where HCPU sleeps and LCPU receives/processes audio through I2S3	Optional
4	I2S signal connections are correct	Optional
5	I2S1 interface digital MIC connection is correct	Optional
6	The peripheral device's I/O logic level matches the main chip's	Optional

3.19. PDM and Analog Audio¶

Table 3.19-1: PDM and Analog Audio Checklist

No.	Check Point	Category
1	PDM dual-mic connection is correct	Optional
2	PDM MIC is powered from a digital supply	Optional
3	The peripheral device's I/O logic level matches the main chip's	Optional
4	Analog dual-mic connection is correct	Optional
5	Analog MIC is powered by MIC_BIAS output	Optional
6	Both audio ADC inputs must each include at least 2.2 uF DC-blocking capacitor	Optional
7	DAC output paths P and N each have a 1 kΩ series resistor, with a 1.5 nF capacitor between them	Optional
8	AW8155 is the recommended audio amplifier; configure it in software for Mode 4 / Class AB mode when using the recommended part	Optional
9	When feeding audio PA output back to the MCU ADC, add a divider and RC filter or additional digital filtering; the divided voltage must stay within the ADC input range, and RC filter cutoff should be 20 kHz	Optional
10	If the chip integrated analog audio ADC path is unused, ADC1P/ADC1N and ADC2P/ADC2N are each recommended to have a 0 Ω series resistor to ground	Optional

3.20. SPI¶

Table 3.20-1: SPI Checklist

No.	Check Point	Category
1	SPI connection is correct; SDO and SDI are crossed correctly between MCU and peripheral	Optional
2	SPI peripheral timing requirements are confirmed and supported	Optional
3	The peripheral device's I/O logic level matches the main chip's	Optional

3.21. USART¶

Table 3.21-1: USART Checklist

No.	Check Point	Category
1	USART4 is designed as the download and log interface	Required
2	USART4 has test points; TXD and RXD are recommended with a series 100 Ω resistor	Required
3	USART1 has a test point	Required
4	Devices that must run on HCPU are connected to USART2 or USART3	Optional
5	Devices that must run on LCPU are connected to USART5 or USART6	Optional
6	When connecting to a peripheral, RXD and TXD are crossed correctly	Required
7	The peripheral device's I/O logic level matches the main chip's	Required
8	Unused USART test points are reserved for backup use	Optional
9	UART connected to peripherals is recommended to use the HCPU interface to avoid HCPU software using an LCPU UART interface	Required

3.22. PWM¶

Table 3.22-1: PWM Checklist

No.	Check Point	Category
1	Backlight PWM pin allocation is correct; use a GPTIMx different from motor PWM, preferably on the PB interface, to avoid HCPU frequency reduction affecting the backlight	Required
2	Motor PWM pin allocation is correct; use a GPTIMx different from backlight PWM, preferably on the PB interface, to avoid HCPU frequency reduction affecting vibration	Required
3	For motor PWM control, select a default-disabled GPIO to avoid abnormal behavior during firmware programming when an SMT motor is used	Required
4	Signals that need PWM output must use the PB interface; also check for cold-boot abnormal behavior	Required

3.23. Debug¶

Table 3.23-1: Debug Checklist

No.	Check Point	Category
1	SWD signal connections are correct	Required
2	The J-Link connector or test points correctly reserve the I/O power supply reference	Required
3	During program download, PVDD, VDDIO, VDDSC, and similar rails must be powered, AVDD18_DSI (CAU2 power) must also be powered	Required

3.24. USB¶

Table 3.24-1: USB Checklist

No.	Check Point	Category
1	USB interface connection is correct	Optional
2	USB interface has ESD protection	Optional
3	During normal non-sleep operation, as long as USB remains enabled, the PC/device side can sense insertion and removal; If MCU sleeps, must sense insertion and removal, add a VBUS resistor-divider circuit, the divider outputs a high level matching the IO voltage, feed into an MCU wake-up pin, sharing the charger-insertion detection wake pin is recommended	Optional

3.25. PBR¶

Table 3.25-1: PBR Checklist

No.	Check Point	Category
1	PBR0 changes from 0 to 1 during power-on and may be used for some external load-switch control; PBR1-PBR5 default to output low	Required
2	PBR0-PBR5 can be used as outputs in both Standby and Hibernate	Optional
3	PBR0-PBR5 can output LPTIM signals	Optional
4	For 567, LPTIM3 is recommended: LPTIM3_OUT and LPTIM3_OUT_BAR output 21-25 kHz signals from PBR pins with different duty cycles and opposite polarity	Optional
5	The 21-25 kHz opposite-polarity signals with different duty cycles may also be output from HCPU ATIM; select suitable ATIMx_CHx and ATIMx_CHxN signals together with Pin_Config and consider the impact of HCPU frequency reduction	Optional
6	PBR0-PBR5 can output a 32 kHz clock signal	Optional
7	PBR0-PBR3 can be configured as wake-up inputs, but after MCU wake-up PBR0-PBRx cannot receive interrupt signals and can only detect 0/1 levels; use with caution	Optional

3.26. Power Consumption¶

Table 3.26-1: Power Consumption Checklist

No.	Check Point	Category
1	For all MOSFET, LDO, and DCDC enable pins used for power switching, reserve a 1 MΩ pull-down to ground when the enable pin is active-high	Required
2	Hibernate-mode base-current requirement is recorded	Required
3	The sum of selected peripheral base currents in Hibernate mode is recorded and meets project requirements	Required
4	Standby-mode base-current requirement is recorded	Required
5	The sum of selected peripheral base currents in Standby mode is recorded and meets project requirements	Required

3.27. Download and Crystal Calibration¶

Table 3.27-1: Download and Crystal Calibration Checklist

No.	Check Point	Category
1	SWD download test points, reserve VBAT, GND, SWDIO, SDCLK, MODE, RSTN, VDDIOA, VDDIOB test point	Required
2	If an offline-download board is required to program firmware, reserve VBAT, GND, UART4_TXD, UART4_RXD, MODE, RSTN, and VDDIOA test points	Optional
3	If crystal calibration is required, reserve a crystal-calibration test point; PB45 is recommended	Optional

4. PCB Layout Checklist¶

Each table below covers one PCB layout review area. When an Applies To column is not present, the row applies to all variants covered by the workbook.

4.1. Package¶

Table 4.1-1: Package Checklist

No.	Check Point	Category
1	Footprint matches the package SPEC	Required

4.2. Power Supply¶

Table 4.2-1: Power Supply Checklist

No.	Check Point	Category
1	VDD1 supply trace is at least 8 mil	Required
2	VDD2 supply trace is at least 8 mil	Required
3	BUCK1_VSW and BUCK1_VOUT trace is at least 8 mil	Required
4	BUCK2_VSW and BUCK2_VOUT trace is at least 8 mil	Required
5	VDDIOA supply trace is at least 10 mil	Required
6	VDDIOA2 supply trace is at least 10 mil	Required
7	VDDIOB supply trace is at least 10 mil	Required
8	VDDIOSA supply trace is at least 6 mil	Required
9	VDDIOSB supply trace is at least 6 mil	Required
10	VDDIOSC supply trace is at least 6 mil	Required
11	AVDD33_USB supply trace is at least 6 mil	Required
12	AVDD33_ANA supply trace is at least 6 mil	Required
13	AVDD_BRF supply trace ≥8 mil	Required
14	AVDD33_AUD supply trace is at least 6 mil	Required
15	AVDD33_DSI supply trace is at least 8 mil	Required

4.3. Power Supply Capacitor and Inductor Placement¶

Table 4.3-1: Power Supply Capacitor and Inductor Placement Checklist

No.	Check Point	Category
1	VDD1 capacitor is placed close to the pin	Required
2	VDD2 capacitor is placed close to the pin	Required
3	BUCK1 inductor is placed close to the chip	Required
4	BUCK1 capacitoras much as possibleclose to the chip pin	Required
5	BUCK2 inductor is placed close to the chip	Required
6	BUCK2 capacitoras much as possibleclose to the chip pin	Required
7	HPSYS_LDO_VOUT capacitor is placed close to the pin	Required
8	LPMU_VDD07_RET capacitor is placed close to the pin	Required
9	LPMU_VDD11_RTC capacitor is placed close to the pin	Required
10	VDDIOA capacitor is placed close to the pin	Required
11	VDDIOA2 capacitor is placed close to the pin	Required
12	VDDIOB capacitor is placed close to the pin	Required
13	VDDIOSA capacitor is placed close to the pin	Required
14	VDDIOSB capacitor is placed close to the pin	Required
15	VDDIOSC capacitor is placed close to the pin	Required
16	AVDD33_USB capacitor is placed close to the pin	Required
17	AVDD33_ANA capacitor is placed close to the pin	Required
18	AVDD_BRF capacitor placed close to the pin	Required
19	AVDD33_AUD capacitor placed close to the pin	Required
20	AVDD33_DSI capacitor is placed close to the pin	Required

4.4. Clock¶

Table 4.4-1: Clock Checklist

No.	Check Point	Category
1	Crystal placed close to the chip	Required
2	GND shielding applied around the crystal	Required
3	Copper keep-out is provided beneath the crystal: at least the top layer on a 4-layer board, and layers 2 and 3 where required	Required
4	Crystal-trace clearance to GND guard copper is greater than 3x the trace width	Required

4.5. Buttons¶

Table 4.5-1: Buttons Checklist

No.	Check Point	Category
1	Button's ESD protection device placed close to the button	Required

4.6. RF¶

Table 4.6-1: RF Checklist

No.	Check Point	Category
1	RF trace meets the single-ended 50 Ω characteristic-impedance requirement	Required
2	RF trace width ≥10 mil	Required
3	Reserved Pi-type antenna matching network placed close to the chip side	Required
4	Continuous GND plane beneath the RF signal	Required
5	No high-speed digital signal traces cross beneath the RF signal	Required
6	No high-di/dt power traces cross beneath the RF signal	Required

4.7. Audio¶

Table 4.7-1: Audio Checklist

No.	Check Point	Category
1	AU_ADC1P and AU_ADC1N parallel traces use ground guarding	Required
2	AU_ADC2P and AU_ADC2N parallel traces use ground guarding	Required
3	AU_DAC1P and AU_DAC1N parallel traces use ground guarding	Required
4	AU_DAC2P and AU_DAC2N parallel traces use ground guarding	Required
5	The AU_DAC1P, AU_DAC1N, AU_DAC2P, AU_DAC2N trace capacitance < 10 pF, length < 2cm	Required

4.8. High-speed Signals¶

Table 4.8-1: High-speed Signals Checklist

No.	Check Point	Category
1	DSI differential signals meet the 100 Ω differential-impedance requirement	Required
2	DSI data differential pairs are length-matched to the clock differential pair within 200 mil	Required
3	DSI signals are routed on the same layer as much as possible	Required

4.9. ADC¶

Table 4.9-1: ADC Checklist

No.	Check Point	Category
1	GPADC signal has no high-speed changing signal routed in parallel, or is properly guarded	Required
2	Battery-voltage divider resistors are placed close to the chip input pin	Required
3	SDMADC signal has no high-speed changing signal routed in parallel, or is properly guarded	Optional

4.10. Test Points¶

Table 4.10-1: Test Points Checklist

No.	Check Point	Category
1	Test-point locations are suitable for probing or fixture soldering	Required
2	Program-download and crystal-calibration test points (VBAT, GND, SWDIO, SWCLK, VDDIOB, MODE, RESET, UART4_TXD, UART4_RXD, etc.) meet fixture size and location requirements	Required

4.11. PCB Stack-up¶

Table 4.11-1: PCB Stack-up Checklist

No.	Check Point	Category
1	The layer adjacent to the main chip must be a continuous main-ground plane	Required