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

Chip Silk Marking Diagram
Pin 1: Position of Pin 1.
Espressif Logo: Company logo.
Product Name: Specifies the chip name.
Product Specification is a code that indicates:
- Operating temperature:
N = Up to 85 °C
H = Up to 105 °C
- (Optional) Flash and PSRAM configuration:
F = In-package flash
R = In-package PSRAM
- (Optional) Voltage level and interface:
No letter = 3.3 V Quad SPI
V = 1.8 V Octal SPI
W = 1.8 V Hex SPI
(Optional) Flash or PSRAM size.
Examples:
- NRW16:
The chip supports up to 85 °C operating temperature, and includes in-package 1.8 V Hex SPI PSRAM (16 MB).
- NR4:
The chip supports up to 85 °C operating temperature, and includes in-package 3.3 V Quad SPI PSRAM (4 MB).
Manufacturing Code: Identifies the chip revision.
Espressif Tracking Information: Identifies the chip lot number.