ROHM - Wireless Communication LSI with built-in Wireless M-Bus Packet Handler

ROHM – Wireless Communication LSI with built-in Wireless M-Bus Packet Handler

The ML7406 from LAPIS Semiconductor Co., Ltd., a ROHM Group Company, is a low power consumption sub GHz RF Transceiver which is compatible with 868MHz Wireless M-Bus, the European smart meter communication standard. Signal processing functions required for each mode are built in, reducing microcontroller load by about 20% and contributing to lower power consumption of the entire system along with longer operating time and reduced maintenance for battery-operated smart meters.

LAPIS Semiconductor, in collaboration with Steinbeis, a major vendor and key member of the group responsible for establishing the OMS (Open Metering System) protocol, developed specifications for hardware-based packet processing and integrated a Wireless M-Bus packet handler into the LSI. The packet handler is designed to perform hardware-based processing of a variety of functions, such as simultaneous standby for interoperability between C and T Modes, automatic discrimination of Format A and B messages in C Mode, and address filtering that automatically distinguishes whether packets are intended for this or other devices.

LAPIS Semiconductor can supply sample software and C source code that include all of the T, C, and S Mode functions compatible with EN113757-4:2011 in the Wireless M-Bus protocol stack. In addition, an industry-standard OMS-compatible protocol stack that can be used without modification in OMS-based meters, along with Wireless M-Bus protocol analysis software, can be licensed from Steinbeis.

Features:

Supported Standard:
- ETSI EN 300 220 (Europe)
- EN 13757-4:2011 (Wireless M-BUS)
- IEEE802.15.4g
- ARIB STD T108 (Japan)
RF frequency: 750MHz to 960MHz
Realized high resolution modulation by using fractional N type PLL direct GFSK Modulation
Modulation: GFSK/GMSK/FSK/MSK (MSK is a case that FSK modulation index = 0.5)
Data transmission rate: 1.2 to 500 kbps
Data encoding/decoding by HW: NRZ, Manchester, 3 out of 6
Data whitening by HW
Programmable frequency channel filters
Programmable frequency deviation function
TX/RX data inverse function
26 MHz oscillator circuits version (ML7406C)
TCXO (26 MHz) direct input version (ML7406T)
SPXO input(CMOS level) version (ML7406S)
Oscillator capacitance fine tuning function
On chip low speed RC oscillation circuit
Low speed clock adjustment function
frequency fine tuning function (using fractional N type PLL)
Synchronous serial peripheral interface(SPI)
On-chip TX PA. (20 mW / 10 mW / 1 mW selectable)
TX power fine tuning function (±0.2 dB)
TX power automatic ramping control
External TX PA control function
RSSI indicator and threshold judgment function
High speed carrier checking function
AFC function (IF frequency automatic adjustment by Fractional N type PLL adjustment)
Antenna diversity function
Automatic Wake UP, auto SLEEP function (external RTC input or internal RC oscillator selectable)
General purpose timer (2ch)
Test pattern Generator (PN9 ,CW, 01 PATTERN, ALL”1”, ALL”0” OUTPUT)
Packet mode function:
- Wireless M-BUS packet format (Format A/B)
- General purpose packet format (Format C)
- Max.255 byte (Format A/B), 204t byte (Format C)
- TX FIFO (64 byte), RX FIFO (64 byte)
- RX Preamble pattern detection (Max.4 byte)
- Automatic TX preamble length generation (Max.length 16383 byte)
- SyncWord setting function (Max. 4byte × 2 type)
- Program CRC function (CRC32/CRC16/CRC8 selectable, fully programmable polynomial)
- Wireless M-BUS field checking function (C-field/M-field/A-field can be detected automatically)
Supply voltage:
- 1.8 V to 3.6 V (TX power 1 mW mode)
- 2.3 V to 3.6 V (TX power 10 mW mode)
- 2.6 V to 3.6 V (TX power 20 mW mode)
Operational temperature: -40 to +85 °C
Current consumption (868 MHz):
- Deep sleep mode 0.1 μA (Typ.)
- Sleep mode2 0.56 μA (Typ.)
- Idle mode 1.4 mA (Typ.)
- TX 20 mW 34 mA (Typ.)
- TX 10 mW 24 mA (Typ.)
- TX 1 mW 13 mA (Typ.)
- RX 15 mA (Typ.)
Package: 32pins WQFN (5mm × 5mm)