ESP8685H4 Part Review

adrian95

adrian95

Fix pin 29 to GND/EP and add datasheet-backed pin descriptions and pin types.

flux

I’ll update the terminal metadata from the Espressif pin table: rename pin 29 to GND/EP, set pin types, and add concise datasheet-backed pin descriptions, then verify the changes.

flux

Pin 29 is now labeled GND/EP; I’m applying the datasheet pin descriptions and electrical pin types next.

flux

Completed and verified the pin metadata update.
Open items:
  • None for this request.
Suggested next steps:
  1. Optionally update the Datasheet URL to the official Espressif PDF.
  2. Optionally change package metadata to QFN28 (4x4 mm).
  3. Optionally refine part type/subtype from generic logic IC to wireless MCU/RF SoC.
Update metadata and review
Update datasheet URL
Fix package metadata
Refine part subtype
Run final review
XTAL_N
Pin Number
25
XTAL_P
Pin Number
26
GPIO18
Pin Number
21
GPIO3
Pin Number
8
MTDI
Pin Number
10
VDD_SPI
Pin Number
18
LNA_IN
Pin Number
1
GPIO9
Pin Number
15
VDDA_2
Pin Number
28
MTCK
Pin Number
12
MTDO
Pin Number
13
GPIO19
Pin Number
22
MTMS
Pin Number
9
XTAL_32K_P
Pin Number
4
GPIO10
Pin Number
16
VDDA_1
Pin Number
27
CHIP_EN
Pin Number
7
U0RXD
Pin Number
23
NC_2
Pin Number
20
XTAL_32K_N
Pin Number
5
GPIO8
Pin Number
14
GND/EP
Pin Number
29
VDD3P3_RTC
Pin Number
11
VDD3P3_CPU
Pin Number
17
VDD3P3_2
Pin Number
3
VDD3P3_1
Pin Number
2
GPIO2
Pin Number
6
U0TXD
Pin Number
24
NC_1
Pin Number
19

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ESP8685H4 Part Review
Date: 2026-07-20
Sources Checked
  • Current Flux part/project: silicon-yard/esp8685h4
  • Existing Datasheet URL property: https://nl.mouser.com/datasheet/2/891/Espressif_Systems_7_27_2022_esp8685_datasheet_en-3002656.pdf
  • Official Espressif datasheet located: https://www.espressif.com/sites/default/files/documentation/esp8685_datasheet_en.pdf
  • Official documentation mirror located: https://documentation.espressif.com/esp8685_datasheet_en.pdf
The existing Datasheet URL property was already populated, so no Datasheet URL update was required by the user’s condition. The existing URL is a Mouser-hosted mirror of the Espressif datasheet; the official Espressif PDF is preferable as canonical metadata.
Current Part Metadata Reviewed

Table

FieldCurrent ValueDatasheet Cross-Check
MPNESP8685H4Matches Espressif ordering code
ManufacturerEspressifMatches
Description2.4 GHz Wi-Fi 4 / Bluetooth 5 LE RISC-V wireless MCU with 4 MB embedded flashMatches datasheet feature set
Part TypeIntegrated CircuitsAcceptable, though a more specific RF SoC / wireless MCU category would be clearer
Package or Case Code28-QFNFunctionally correct; datasheet calls package QFN28 (4×4 mm)
Terminal count29Correct: 28 QFN perimeter pins plus exposed ground pad / pin 29
MountSurface MountCorrect
Datasheet URLMouser mirrorContent is correct, but official Espressif URL is more canonical
Key Datasheet Specs

Table

SpecESP8685H4 Datasheet Value
WirelessIEEE 802.11 b/g/n 2.4 GHz Wi-Fi; Bluetooth 5 LE; Bluetooth mesh
CPU32-bit RISC-V single-core, up to 160 MHz
Memory384 KB ROM, 400 KB SRAM, 8 KB RTC SRAM
Embedded flash4 MB SiP flash
Supply voltage3.0 V min, 3.3 V typical, 3.6 V max for VDDA/VDD3P3/VDD3P3_RTC/VDD3P3_CPU
Recommended supply current capacity500 mA minimum if using a single supply
Operating ambient temperature-40 °C to +105 °C
PackageQFN28, 4 mm × 4 mm
Lead pitch0.4 mm BSC
Exposed pad size2.6 mm min, 2.7 mm nominal, 2.8 mm max
Absolute max supply-0.3 V to 3.6 V
Storage temperature-40 °C to +150 °C
Pinout Cross-Check
The current terminal numbers and names match the datasheet pin table except for expected uniqueness suffixes and the exposed pad naming noted below.

Table

PinDatasheet NameCurrent TerminalResult
1LNA_INLNA_INMatch
2VDD3P3VDD3P3_1Match with uniqueness suffix
3VDD3P3VDD3P3_2Match with uniqueness suffix
4XTAL_32K_PXTAL_32K_PMatch
5XTAL_32K_NXTAL_32K_NMatch
6GPIO2GPIO2Match
7CHIP_ENCHIP_ENMatch
8GPIO3GPIO3Match
9MTMSMTMSMatch
10MTDIMTDIMatch
11VDD3P3_RTCVDD3P3_RTCMatch
12MTCKMTCKMatch
13MTDOMTDOMatch
14GPIO8GPIO8Match
15GPIO9GPIO9Match
16GPIO10GPIO10Match
17VDD3P3_CPUVDD3P3_CPUMatch
18VDD_SPIVDD_SPIMatch
19NCNC_1Match with uniqueness suffix
20NCNC_2Match with uniqueness suffix
21GPIO18GPIO18Match
22GPIO19GPIO19Match
23U0RXDU0RXDMatch
24U0TXDU0TXDMatch
25XTAL_NXTAL_NMatch
26XTAL_PXTAL_PMatch
27VDDAVDDA_1Match with uniqueness suffix
28VDDAVDDA_2Match with uniqueness suffix
29GNDEPMismatch / should be GND or GND/EP
Footprint Cross-Check
Current footprint asset: QFN40P400X400X90-29N.kicad_mod

Table

Footprint FeatureCurrent FootprintDatasheet ValueResult
Body / fab outline4 mm × 4 mmQFN28 4 mm × 4 mmMatch
Perimeter pads28QFN28 perimeter leadsMatch
Total pads including center pad29Pin 29 GND exposed padMatch
Pitch0.4 mm0.4 mm BSCMatch
Perimeter pad width0.2 mmLead width 0.15 / 0.20 / 0.25 mmNominal match
Perimeter pad length0.75 mm landPackage lead length 0.25 / 0.35 / 0.45 mmPlausible land pattern; datasheet package drawing is not a full recommended PCB land pattern
Exposed pad2.8 mm × 2.8 mmEP size max 2.8 mm, nominal 2.7 mmWithin package max; verify against Espressif land-pattern guidance if available
Pin 1 markerPresent near pin 1Required by conventionOK
Mismatches and Recommendations
  1. Pin 29 is named EP in Flux but GND in the datasheet. Functionally this is the exposed ground pad, but the official pin name is GND. Recommended terminal display/name: GND or GND/EP.
  2. Pin descriptions are missing in the Flux terminals. The datasheet includes useful functions for every pin, such as GPIO18, USB_D-, GPIO19, USB_D+, and CHIP_EN behavior. Add Pin Description properties from Table 3.
  3. Pin Type is Unspecified for every terminal. Recommended types should reflect the datasheet: power pins as Power In, GND as Ground, NC pins as Not Connected, CHIP_EN as Input, and GPIO/RF pins as bidirectional or I/O.
  4. Datasheet URL is a distributor mirror. It is populated and valid, but the official Espressif PDF is preferable for canonical library metadata.
  5. Package naming is correct but non-canonical. 28-QFN is understandable; QFN28 (4×4 mm) more directly matches the datasheet.
  6. Part type/subtype metadata is broad/questionable. Library search reports Integrated Circuits / Logic and logic function AND, which does not represent this RF SoC/wireless MCU.
Internal Quality Report
An internal part-quality report was filed for the key library metadata issues: pin 29 naming, missing pin descriptions, unspecified pin types, distributor datasheet URL, and non-representative IC subtype/logic metadata.
Metadata Fixes Applied
2026-07-20 update:
  • Renamed pin 29 terminal from EP to GND/EP.
  • Added datasheet-backed Pin Description properties for all 29 terminals from Espressif Table 2-1 / ESP8685H4 pin description.
  • Replaced Unspecified pin types with electrical types based on the datasheet: GPIO/RF pins as Bi-Directional, supply pins as Power In, NC pins as Not Connected, CHIP_EN and XTAL_P as Input, XTAL_N as Output, and pin 29 as Ground.

  • Sources Checked

  • Current Part Metadata Reviewed

  • Key Datasheet Specs

  • Pinout Cross-Check

  • Footprint Cross-Check

  • Mismatches and Recommendations

  • Internal Quality Report

  • Metadata Fixes Applied

Documents

Assets

ESP8685H4

QFN40P400X400X90-29N.kicad_modFootprint
ESP8685H4-thumb.png

ESP8685H4-thumb.png

ESP8685H4-thumbThumbnail
ESP8685H4

ESP8685H4

ESP8685H4.stp3D Model

ESP8685H4

ESP8685H4 Symbol.svgDefault

ESP8685H4

ESP8685H4 thumbnail
IC RF TxRx + MCU Bluetooth, WiFi 802.11b/g/n, Bluetooth v5.0 2.4GHz 28-VFQFN Exposed Pad
ESP8685H4 is a 2.4 GHz Wi-Fi 4 and Bluetooth® 5 (LE) wireless microcontroller integrating a 32-bit RISC-V single-core processor with 4 MB embedded flash memory. It operates from a 3.0 V to 3.6 V supply, supports IEEE 802.11 b/g/n and Bluetooth 5 LE, and provides multiple peripherals including SPI, UART, I²C, I²S, PWM, ADC, RMT, TWAI®, and GPIO for embedded wireless applications.
#WiFiModule #BluetoothLE #MCU #2_4GHz #RISCV #Embedded

Properties

ESP8685H4

Espressif Systems

Integrated Circuits

documentation.espressif.com/esp8685_datasheet_en.pdf

IC

Surface Mount

28-QFN

parametric-v1

creativecommons.org/licenses/by/4.0/

Pricing & Availability

DPN

Stock

Qty 1

1

1.7K

$1.3435

1

2.1K

$2.84

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