Chip Silk Marking

Espressif chip silk marking provides information such as chip name, flash size, and operating temperature.

Marking Convention

Diagram showing chip marking information — Chip Silk Marking Diagram

Pin 1: Position of Pin 1.
Espressif Logo: Company logo.
Product Name: Specifies the chip name.
Date Code: WW is the week number of year YYYY. Example: Date Code “122017” stands for the 12th week of year 2017.
Flash Code is a code that indicates:
- (Optional) Temperature and flash size.
- The tracking information of the in-package flash.
The arrangement of the flash code can vary by product. Please see Flash Code and PSRAM Code Conventions for details.
PSRAM Code is a code that indicates:
- (Optional) Temperature and PSRAM size.
- The tracking information of the in-package PSRAM.
The arrangement of the PSRAM code can vary by product. Please see Flash Code and PSRAM Code Conventions for details.

Espressif Tracking Information: The second character of this code correlates to the chip revision. For details, see ESP32 Series SoC Errata.

Chip Revision Identification by Chip Marking
Chip Revision	Espressif Tracking Information
v0.0	XXXXXXXX
v1.0	X `B` XXXXXX
v1.1	X `F` XXXXXX
v3.0	X `E` XXXXXX
v3.1	X `G` XXXXXX

Flash Code and PSRAM Code Conventions

Based on the in-package flash or PSRAM, ESP32 chips can be divided into the following categories.

No Flash, No PSRAM

This section applies to ESP32 chips without any in-package flash or PSRAM. For such chips, flash code and PSRAM code are simply left empty.

In-package Flash, No PSRAM

This section applies to ESP32 chips with only in-package flash. For such chips, only the flash code is used. PSRAM code is left empty.

(Optional) Temperature (2 characters):
- FH: 105 °C
- FN: 85 °C

(Optional) Size (1 character):
- 2: 2 MB
- 4: 4 MB
- 8: 8 MB
Flash Tracking Information (7 characters).

Note

For ESP32-U4WDH, ESP32-PICO-V3 and ESP32-PICO-D4, the flash codes are not provided on the silk markings.

In-package PSRAM, No Flash

This section applies to ESP32 chips with only in-package PSRAM. For such chips, only the PSRAM code is used.

Flash Code and PSRAM Code Diagram - In-package PSRAM, No Flash

Size (5 or 6 characters):

R2-V3: 2 MB, -40 °C ~ 85 °C

RH2-V3: 2 MB, , -40 °C ~ 105 °C

PSRAM Tracking Information (9 characters).

In-package Flash, In-package PSRAM

This section applies to ESP32 chips with both in-package flash and PSRAM. For such chips, both flash code and PSRAM code are used.

(Optional) Temperature (1 character):
- H: 105 °C
- N: 85 °C
(Optional) Flash Size (1 character):
- 4: 4 MB
- 8: 8 MB
(Optional) PSRAM Size (2 characters):
- R2: 2 MB
- R8: 8 MB
Flash Tracking Information (7 characters).
PSRAM Tracking Information (9 characters).

Note

For ESP32-PICO-V3-02, the flash code and PSRAM code are not provided on the silk markings.