Lapis ML7421 Achieves 300kbps

Rohm group company Lapis Semiconductor has announced the availability of a multiband (sub-1GHz/2.4GHz) wireless communication LSI, ML7421, aimed at applications requiring low power consumption over distance, such as smart meters, alarms, smart agriculture and building security systems.

The ML7421 supports both sub-1GHz (400MHz to 960MHz) and 2.4GHz. By supporting the 2.4GHz band available world-wide, a single device can be deployed globally. Additionally, in environments where communication at 2.4GHz is unstable, long-distance sub-1GHz communication is available.

2.4GHz and sub-1GHz can be used as bridged communication depending on the application or the environment.

The ML7421 can be used in radio stations compliant to ETSI EN 300 200, FCC PART15, and ARIB STD-T66, T67, T108 with packet handling functions based on wireless m-bus and IEEE802.15.4g.

Lapis claims the LSI has stable wireless characteristics even with environmental changes such as voltage and temperature fluctuations. Fluctuations over temperature (-40 to 85℃) are 0.5dB in TX output power and 1.0dB in RX sensitivity.

Improving delta-sigma ADCs makes it possible to achieve flexible data rate demodulation up to 300kbps for global usage, while improving receiver sensitivity.

As a result, the ML7421 is suitable for equipment used outdoors such as smart meters and various IoT sensors. These characteristics make it possible to extend long-range communication further with high power amplifier.

Low power design technology allows Lapis to decrease average current consumption by 15% during the general sensor operation (in 5-second intervals, sleep mode, transmitter(TX) mode and receiver(RX) mode are included).

Improving the dc-dc converter and the class-E power amplifier reduces transmitter (TX) mode current consumption down to 27mA at 13dBm output. In addition radio wave check function reduces the time required for start-up of reception, bringing the total time for receiver strength detection to approximately 1ms.