CC2500 RF ICs and 4-in-1 RC Transmitter Modules

CC2500 parts and multi-protocol 2.4 GHz transmitter hardware

This small assortment combines loose RF transceiver IC choices with assembled four-radio RC transmitter modules and an A7105-based module. A CC2500 chip is not the same item as a complete external transmitter module, and a product headline mentioning CC2500, CC1101, nRF24L01 and A7105 can list alternatives rather than everything supplied. Identify the actual selected variant, transmitter-bay format and firmware before ordering.

What the selected hardware is

• Individual CC2500 or CC1101 IC: one listing has CC2500RGPR (square), CC2500RTKR (round), CC1101RGPR (square) and CC1101RTKR (round) choices. “Square” and “round” are seller labels for package/packaging choices, not evidence of identical chips. The CC2500 is a 2.4 GHz RF device, whereas CC1101 is a separate sub-GHz transceiver family. The selected QFN-20 IC is a component for an appropriately designed PCB, not an Arduino plug-in module or a preprogrammed transmitter. Check the manufacturer's exact part-number suffix, RF matching, supply, land pattern and reel/cut-tape format before a PCB build.
• IRX4 Lite/Plus four-in-one modules: assembled transmitter modules integrate CC2500, nRF24L01-family, A7105 and CYRF6936 radios with a controller to support selected RC protocols when the host transmitter firmware and model settings support them. One listing offers IRX4 Lite and IRX4 Plus as distinct variants; another describes an IRX4 LITE intended for an X-Lite-format host. Bay dimensions and electrical interfaces differ. These are transmitter add-ons, not standalone receivers, complete handheld radios or four loose ICs supplied separately.
• Host-specific RC choices: “For Flysky,” “For JR DSM2,” “For Frsky,” “For FRSKY TX,” “For FLYSKY TX” and “For JR TX” are different selected configurations or fitments on two further multiprotocol listings. Do not assume one variant plugs into every module bay or directly binds to every FrSky, Flysky or JR receiver. Match the module's physical format, PPM/serial interface, host firmware, chosen over-the-air protocol and receiver generation.
• MD7105-SY alternative: the 1pc through 10pcs options of a listing identify an A7105-based 2.4 GHz SPI transceiver module, despite “CC2500 NRF24L01” appearing as comparison terms in its headline. Its source description specifies a 3.3 V module and discusses a test range around 120 m under an open-area setup; neither establishes that it is a CC2500, an nRF24L01 or a Wi-Fi module. Choose A7105 only where the host firmware and link partner support A7105's radio protocol.

How the four-radio transmitter architecture works

A multiprotocol TX module selects a radio chip and an implemented receiver protocol through compatible transmitter firmware or supported PPM configuration. The module's CC2500 path, nRF24L01 path, A7105 path and CYRF6936 path serve different air protocols. Their presence on one PCB does not make the underlying ICs pin-compatible, allow an arbitrary receiver to bind or turn the module into Wi-Fi or Bluetooth. Examples in source listings include various FrSky/Futaba-style modes via CC2500, Flysky-related modes via A7105, DSM/DEVO-style modes via CYRF6936 and other modes via the nRF24L01 path. Actual protocol availability is firmware-, version-, region- and receiver-dependent; verify the exact receiver's protocol/subprotocol before flight or production use.

Several supplier descriptions mention PPM and serial operation. PPM typically relies on the host producing a compatible PPM signal and the module's selected switch position; serial mode relies on supported model-menu configuration, such as a compatible external MULTI/MULT setting on appropriate transmitter firmware. The listings describe different controller generations, including ARM/APM32-based new stock and STM32-branded versions. Therefore do not assume a specific controller chip, factory firmware release, number of protocols or flashing method from a shared product title. Confirm the actual hardware revision and host-firmware support. The selected “IRX4 Lite” need not have the same voltage-input range, dimensions, bay pinout or control current as “IRX4 Plus”; treat each product's own documentation as authoritative.

CC2500 IC design considerations

For a board-level design, the CC2500 component requires appropriate supply regulation, RF matching and antenna layout, oscillator/reference configuration, host digital interface and software controlling packet parameters. An unpopulated QFN IC has no antenna, crystal, programmed RC protocol, USB connector, compliant enclosure or ready-to-use transmitter bay. Confirm the precise CC2500RGPR or CC2500RTKR package and assembly format in the variant you select; the neighboring CC1101RGPR/RTKR selections are a different radio family with different RF frequencies and integration requirements. Do not reuse a CC2500 2.4 GHz antenna network as a validated CC1101 sub-GHz layout or assume a CC1101 choice will talk directly to a CC2500.

Installation and compatibility checks for RC modules

1. Choose a transmitter fitment: verify JR-style bay, X-Lite-style bay or the specific Flysky/FrSky/JR configuration shown for the selected option. An antenna or case pictured in one version does not define every variant's contents.
2. Identify the host signaling: determine whether your transmitter and module revision support PPM, a serial multiprotocol mode or both, and confirm firmware feature flags and update procedures for that hardware.
3. Match the receiver: select the correct radio family, protocol, subprotocol and channel mapping; protocol names in a listing are not proof of universal receiver compatibility. Perform binding and fail-safe testing with the actual receiver on the bench.
4. Verify electrical ratings: source listings give different whole-module supply figures for different IRX4 units, while a loose CC2500 IC and MD7105-SY have their own low-voltage limits. Never transfer an assembled transmitter module's 5–14 V bay-input claim to a bare QFN transceiver or 3.3 V A7105 board.
5. Confirm antenna and regulation: check 2.4 GHz antenna connection, any country-specific transmission limits, model firmware and radio range in real use. A listed +22 dBm figure belongs to a particular assembled TX module claim, not every chip or option in this collection.

Frequently asked questions

Is this all CC2500 silicon? No. The QFN listing includes separate CC2500 and CC1101 variants, multiprotocol boards contain multiple chip families, and MD7105-SY is A7105-based.

Does a four-in-one module include a handheld controller and receiver? The descriptions identify a transmitter add-on; the controller/receiver are not established as included. Check the selected listing's package contents.

Can the CC2500 QFN part replace an IRX4 module? No. One is a bare IC requiring PCB and firmware engineering; the other is a host-specific, assembled multiprotocol transmitter accessory.

Does the phrase “for FrSky/Flysky/JR” guarantee every receiver works? No. Module bay fit, transmitter firmware, receiver protocol and binding/failsafe behavior all need validation for the selected option.

For any RC installation, confirm hardware revision and compliance in the region of operation, then verify antenna, binding, control response and fail-safe settings before using a model.