The Ebyte E49-900T20S is an ultra-cost-effective SMD wireless data transmission module operating in the 850-930MHz (ISM 915MHz) sub-GHz band, powered by the CMT2300A RF chip and delivering up to 20dBm transmit power for reliable line-of-sight communication up to 2.5km. Featuring a compact 26x16mm footprint, GFSK modulation, 1.2k-200kbps air data rate, 1.3uA sleep power consumption, and dual IPEX/stamp hole antenna options, it supports 4 flexible operating modes for long-range industrial IoT telemetry.
| Parameter Specification | E49-900T20S | E49-900T20S + TX915-FPC-8521 | E49-900T20S + TX915-JKS-IPX20 |
|---|---|---|---|
| Operating Frequency | 850 to 930 MHz (Supports 868MHz / 915MHz ISM Band) | ||
| RF Transceiver IC | CMT2300A | ||
| Transmit Power | Max 20 dBm (approx. 100 mW, software adjustable) | ||
| Receiving Sensitivity | -114 to -116 dBm (at 1.2 kbps air rate) | ||
| Communication Distance | 2500m (Clear open area, 5dBi gain, 2.5m height) | Compact indoor / embedded flexible enclosure range | Extended omnidirectional field communication range |
| Antenna Interface / Type | IPEX 1st Gen / Stamp Hole (50 Ohm) | Bundled internal FPC antenna (IPEX connector) | Bundled high-gain rubber duck antenna + IPEX cable |
| Air Data Rate | 1.2k, 2.4k to 200 kbps (Configurable) | ||
| Modulation Type | GFSK | ||
| Operating Voltage | 3.3V to 5.0V DC (Typical: 5.0V, Max: 5.5V) | ||
| Communication Level | 3.3V TTL (Requires level conversion for 5V TTL) | ||
| Power Consumption | TX: 97.9 mA | RX: 12.04 mA | Sleep: 1.3 uA | ||
| Communication Interface | UART Serial Port (1.27mm pin pitch SMD package) | ||
| FIFO / Cache Capacity | 54 Bytes FIFO (Auto-subpacketizing) / 500 Bytes Cache | ||
| Dimensions & Weight | 26 x 16 mm | 2.1g | ||
| Operating Temperature | -40 to +85 deg C (Industrial-grade design) | ||
| Main parameter | Description |
Remark |
| Distance for reference |
2500m |
Test condition：clear and open area, antenna gain:5dBi,antenna height:2.5m，air data rate:1.2kbps |
| FIFO |
54 Btye |
Maximum capacity of single transmission, auto-sub-packing when exceeding |
| Cache capacity |
500 Btye |
- |
| Modulation |
GFSK |
- |
| Communication interface |
UART serial port |
- |
| Package |
SMD |
- |
| Connector |
1.27mm |
- |
| Size |
26*16mm |
- |
| Antenna |
IPEX/Stamp hole |
50 ohm impedance |
| Main parameter | Min. | Typ. | Max. | Unit | Remark |
| Operating voltage |
3.3 |
5 | 5.5 | V | Over 5.5V will permanently damage module |
| Operating frequency |
850 |
868 |
930 |
MHz |
Support ISM band |
| Communication level | - | 3.3 | - | V | For 5V TTL, it may be at risk of burning down |
| TX current | - |
97.9 |
- | mA | Instant power consumption |
| RX current | - | 12.04 |
- | mA |
- |
| Sleep current | - | 1.3 |
- | μA | Software is shut down |
| Operating temperature |
-40 | - |
+85 | ℃ | Industrial design |
| Max Tx power |
- | - | 20 | dBm |
- |
| Receiving sensitivity |
-114 |
-115 |
-116 |
dBm |
Air data rate is1.2kbps |
| Air data rate |
1.2k | 2.4k | 200k | bps |
Controlled via user’s programming |
Practical Application Scenarios
1. Solar-Powered Smart Agricultural Irrigation and Soil Sensor Nodes
Agricultural IoT system integrators use the E49-900T20S wireless module integrated into field soil moisture probes and valve controllers. Operating in mode 2 or wake-on-radio WOR mode, the module draws only 1.3 uA during sleep, extending battery life up to several years on small solar panels. The sub-GHz 915MHz GFSK signal bypasses dense crop foliage and greenhouse walls, delivering reliable sensor telemetry over 2 km back to a centralized gateway.
2. Decentralized Industrial Utility Metering and Modbus RTU Telemetry
In smart grid and automated water distribution networks, engineering teams integrate the E49-900T20S into electric meters and flow sensors. Utilizing the UART interface and 500-byte cache memory, the module transparently transmits Modbus RTU data packets without needing complex protocol translation. Its 20dBm output power enables penetrate through concrete walls and basement enclosures to link remote sensors to industrial DTUs or edge gateways.
3. Multi-Node Building Automation and Environmental HVAC Control
Building management engineers embed the E49-900T20S into indoor wireless temperature, humidity, and air quality monitors. Operating across the 850 to 930 MHz spectrum, the module avoids interference from crowded 2.4 GHz Wi-Fi and Bluetooth channels in commercial buildings. Combined with flexible FPC antennas attached via IPEX connectors, nodes can be hidden inside ultra-thin wall mounts while maintaining steady multi-floor wireless links.
FAQ Section
1. What are the 4 operating modes of the E49-900T20S and how do I switch between them?
The E49-900T20S features Mode 0 (Transparent Transmission Mode), Mode 1 (WOR Transmitter Mode), Mode 2 (WOR Receiver / Power Saving Mode), and Mode 3 (Sleep / Configuration Mode). Operating modes are controlled by setting the high/low logic levels on the onboard M0 and M1 control pins via your host MCU or DIP switches.
2. Can I directly connect the UART pins of the E49-900T20S to a 5V microcontroller like a standard Arduino?
The communication signal logic level of the E49-900T20S is 3.3V TTL. Although the power supply pin accepts up to 5V DC, connecting 5V TTL UART signals directly to the RXD and TXD pins poses a risk of damaging the module. A 3.3V-to-5V bidirectional logic level converter or series resistor circuit is required when interfacing with 5V microcontrollers.
3. What happens if my single data transmission exceeds the 54-byte FIFO buffer limit?
The E49-900T20S contains a 54-byte single-transmission FIFO and a 500-byte continuous cache memory. If the data packet sent over UART exceeds 54 bytes, the module automatically handles sub-packetization and continuous transmission without losing data, ensuring transparent streaming up to the total cache capacity.
4. Does the E49-900T20S require licensing for industrial deployment in North America or Europe?
The module operates within the license-free Sub-GHz ISM bands (868 MHz for Europe and 915 MHz for North America). As long as your final product complies with local ERP/EIRP power limits and duty cycle regulations, no individual radio station license is required for operation.
