ZR-3A 433MHz ASK RF Receiver Module with TTL Output and AGC

The ZR-3A is a compact 433MHz RF receiver module designed for short-range wireless data reception in remote control, security, and automation projects. It operates on the ASK (Amplitude Shift Keying) modulation principle and employs a super-regenerative receiving architecture, which keeps the circuit simple and the cost low while remaining effective for typical low-data-rate remote control signals. The module operates from a 5V DC ± 0.3V supply and draws only 2.5mA, making it suitable for battery-powered and energy-sensitive devices. Its receiver sensitivity is rated at -106dBm, allowing it to pick up weak signals from compatible 433MHz ASK transmitters.

The ZR-3A delivers a TTL-level output, which means it can connect directly to the digital input of an Arduino, STM32, ESP32, or any other 3.3V/5V microcontroller without additional level-shifting circuitry. The module includes an automatic gain control (AGC) circuit that adjusts the amplification factor according to the received signal strength, helping to stabilize the output when the distance between the transmitter and receiver changes. Because the AGC applies maximum gain when no signal is present, the output may show noise in idle conditions; this is typically handled in software by using Manchester encoding to ensure reliable data detection.

The board measures 30.3mm × 14.9mm × 9mm, and a 18cm antenna wire is recommended for best performance. The working range is approximately 100 meters in open space, depending on the matching transmitter and environmental conditions. The module operates across a temperature range of -10°C to +60°C and is widely used in car alarm systems, remote-controlled electrical switches, automatic doors and shutters, home automation, and educational wireless communication projects.