Semtech SX1308 IMLTRT Indoor Micro Gateway Digital Baseband Chip

Semtech SX1308 is a digital baseband chip mainly used for indoor LoRaWAN pico gateways, with a sensitivity of -139dBm and dynamic data rate adjustment (ADR). The SX1308 digital baseband chip is a huge digital signal processing engine, specially designed to provide breakthrough gateway functions in the ISM worldwide, and integrates LoRa concentrator IP.

Functional block diagram:

SX1308 generally connects two SX1257 (or SX1255). SX125x is a radio frequency front-end chip, which is responsible for converting I/Q (In-phase / Quadrature, in-phase quadrature digital signals) into radio analog signals.

• 2x SX1257 radio front end supports 868 MHz bands and antenna diversity

• 2x SX1255 radio front end is 433 MHz band with antenna diversity support

• 1x SX1257 and 1x SX1255, dual-frequency operation can be performed simultaneously

The IF of all modems can independently adjust the baseband bandwidth within the allowed radio range, such as ±400khz. Provides optimized firmware to optimize the settings of the SX1257/55 radio and performs real-time automatic gain control. As shown in the following block diagram:

Semtech SX1308 features:

• Up to -139dBm sensitivity with SX1257 or SX1255 Tx/Rx front end

• 70dB continuous wave interference offset at 1MHz

• Can work under negative signal-to-noise ratio

• CCR up to 9dB

• 49x LoRa demodulator and 1x (G)FSK demodulator

• Dual digital Tx and Rx radio front-end interface

• 10 programmable parallel demodulation paths

• Dynamic data rate adjustment (ADR)

Semtech SX1308 Product Description

SX1308 is a constant frequency and uses a 6-pin SOT23 current-mode boost converter, so it is suitable for small, low-power applications. It is worth noting that the switching frequency of SX1308 is 1.2MHz, and small and low-cost capacitors and inductors with a height of less than 2mm can be used. Internal soft-start reduces inrush current and extends battery life. SX1308 has the function of automatically switching to pulse frequency modulation mode under a light load. SX1308 includes under-voltage lockout, current limit, and thermal overload protection to prevent damage in case of an output overload.

sx1308 module

Semtech SX1308 application areas:

• Smart metering

• Secure sensor network

• Agricultural monitoring

I will talk about the relevant discussion and introduction of LoRa technology today. The development prospects of LORA are very impressive. What Jotrin will introduce to you today is only a small part of it. If you want to discuss more related issues about LORA technology, Please pay attention to the Lora column of our technical articles.

Tag: sx1308，Semtech

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