Renesas M306N4FCTFP#BTQ

Overview

CYRF6936 from Cypress Semiconductor is a 2.4 GHz WirelessUSB™ LP Radio SoC integrating DSSS/GFSK transceiver, 16-byte TX/RX FIFOs, Auto Transaction Sequencer (ATS), Power Management Unit (PMU), and SPI interface. It delivers +4 dBm transmit power, –97 dBm receive sensitivity, and supports data rates up to 1 Mbps in GFSK mode. Designed for ultra-low-power coin-cell applications, it operates from 1.8 V to 3.6 V and targets wireless peripherals like keyboards and remote controls.

For engineers reviewing the CYRF6936 datasheet, CYRF6936 pinout, CYRF6936 application, or CYRF6936 equivalent, key selection considerations include its 40-pin QFN package, sleep current <1 µA, AutoRate™ dynamic data rate reception, RSSI reporting, and SPI-controlled PMU with VREG output for external sensor/MCU supply.

Technical Context

The CYRF6936 implements a dual-conversion low-IF 2.4 GHz radio architecture with integrated PA (–35 to +4 dBm in 7 steps) and LNA with configurable gain control. Its baseband handles DSSS spreading/despreading using 32/64-chip PN codes, SOP/EOP detection, CRC16 generation/checking, and automatic ACK packet generation.

It features a hardware Auto Transaction Sequencer that autonomously manages full packet transmission (TX → RX → ACK wait) and reception (RX → TX ACK → RX) without MCU intervention for ≤16-byte packets. The SPI interface remains fully functional during sleep mode, enabling register access while the 12 MHz oscillator is disabled.

Key Specifications

Pinout & Package

40-pin QFN package (6 × 6 mm, 0.5 mm pitch) with exposed thermal pad (E-PAD) requiring soldering to ground. Pin 1 marked by corner tab; NC pins must be connected to GND per datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2.4 GHz proprietary radio SoC applications.

Compared with CC2530F256 and nRF24L01+, the CYRF6936 uniquely combines DSSS/GFSK dual-mode operation, hardware ATS, integrated PMU with VREG output, and <1 µA sleep current-making it optimal for ultra-low-power, firmware-light HID and sensor applications without protocol stack overhead.

Availability

CYRF6936 is available at Aetrix Electronics and suitable for wireless peripherals, home automation sensors, remote controls, and consumer audio accessories requiring stable component supply and long-term lifecycle support.

Supply support for CYRF6936 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in programmable system-on-chip (PSoC), memory, and connectivity solutions.

The CYRF6936 belongs to the WirelessUSB™ LP family, engineered specifically for low-cost, low-power, license-free 2.4 GHz proprietary wireless links in human interface devices and battery-operated IoT endpoints.

FAQ

What is the maximum packet length supported by the CYRF6936?

The CYRF6936 supports packets up to 255 bytes in length. However, the actual usable payload depends on clock accuracy and selected data mode. Its internal 16-byte TX/RX FIFOs require MCU intervention for packets exceeding 16 bytes-using interrupt-driven buffer management to prevent overflow during transmission or reception of longer frames. The CYRF6936 datasheet specifies timing constraints for multi-packet burst transfers.

Does the CYRF6936 support over-the-air firmware updates?

The CYRF6936 does not include built-in bootloader or flash memory for over-the-air (OTA) firmware updates. It is a radio transceiver SoC without an embedded programmable MCU core. Firmware resides on an external host microcontroller, which communicates with the CYRF6936 via SPI. OTA capability must be implemented in the host MCU's application layer using CYRF6936's packet transmission and reception functions.

Can the CYRF6936 operate without an external crystal?

No-the CYRF6936 requires a 12 MHz ±30 ppm fundamental-mode crystal connected directly between XTAL and GND, with no external load capacitors. The oscillator circuit is internal and optimized for this specific crystal configuration. Using an external clock source or omitting the crystal prevents proper RF synthesizer operation and invalidates all timing-critical functions including packet framing, SPI synchronization, and sleep/wake transitions.

How does the CYRF6936 handle coexistence with Bluetooth or Wi-Fi in the 2.4 GHz band?

The CYRF6936 mitigates 2.4 GHz band interference through frequency agility (98 selectable 1 MHz channels), AutoRate™ dynamic data rate switching, and RSSI-based channel selection. Its DSSS mode provides inherent processing gain against narrowband interferers like Bluetooth piconets. Unlike Wi-Fi or Bluetooth, it avoids crowded channels (e.g., 2412–2472 MHz) by selecting less congested frequencies, and its fast channel settling (≤100 µs on 25 channels) enables rapid hopping during active links.

Is the CYRF6936 RoHS compliant and qualified for industrial temperature range?

The CYRF6936 is RoHS compliant per Cypress documentation and rated for operation from 0 °C to +70 °C ambient temperature. It is not specified for extended industrial range (–40 °C to +85 °C). For designs requiring wider temperature tolerance, derating analysis and validation under actual operating conditions-including crystal stability, PA output consistency, and PMU regulation-are necessary before deployment.