Introducing the New ESP32-PICO-D4 SIP

Alasdair Allan
3 min readAug 24, 2017


The ESP8266 was a breakthrough success for Espressif Systems. Since it first came to the attention of makers back in 2014 it has become the “third community” in the maker electronics world, alongside the Arduino and the Raspberry Pi. As a result, last year’s release of the ESP32 was highly anticipated.

The ESP32 was faster, had better WiFi, support for Bluetooth LE, and it was only slightly more expensive—and importantly for the Internet of Things, it also had onboard security support. So the announcement a couple of days ago that Espressif is introducing an ESP32-based System-in-Package (SIP) module, the ESP32-PICO-D4, is arguably rather important.

The new ESP32-PICO-D4 (📷: Espressif System)

The new ESP32-PICO-D4 SIP combines an ESP32 SoC, crystal oscillator, filter capacitors, RF matching links, and 4MB flash, into a single 7 mm × 7 mm QFN package.

“With its ultra-small size, robust performance and low-energy consumption, ESP32-PICO-D4 is well suited for any space-limited or battery-operated applications, such as wearable electronics, medical equipment, sensors and other IoT products.”

Including the passive components in the design means that the new QFN package needs very little external support to be used on your own PCB. Making it perfectly suited for wearables and other Internet of Things devices.

The ESP32 at the heart of the package has a Tensilica Xtensa dual-core 32-bit LX6 microprocessor, with 448KB of ROM and 520KB of SRAM (including 8KB of RTC memory) and a 1KB eFuse. The SIP module integrates 4MB of SPI Flash memory, although as the ESP32 can support up to 16MB it’s possible we might see that in future revisions

Wireless connectivity support is 802.11 b/g/n/e/i (802.11n up to 150 Mbps), alongside Bluetooth V4.2 (BR/EDR and Bluetooth LE support).

The module interfaces include SD card, UART, SPI, SDIO, LED PWM, Motor PWM, I2S, I2C, IR, as well as GPIO, capacitive touch sensor, ADC, DAC, and a LNA pre-amplifier. The chip also has two onboard sensors—a Hall sensor to detect magnetic fields, and a temperature sensor.

“Years ago, we were the first WiFi company to integrate the power amplifier, balun and switch within a single piece of silicon (ESP8089) and have good RF performance. This reduce the cost and BoM to only 7 components. We make hardware design as simple as possible for our customers, and remove that uncertainty and dreadful hardware iterations, possibly saving many projects along the way. We are still looking into creating something more interesting; expect something different from us in the near future!” — John Lee 李赤水, Espressif Systems.

Unfortunately, outside of the datasheet, there really isn’t other any information about the new ESP32-based SIP available. We don’t have a release date, or other time scales, and we don’t yet have a price point. However, like many of you, I’m looking forward to getting my hands on some samples and seeing what we can do with them.