LimeNET-Micro v2.1 hardware description

LimeNET-Micro Board Key Features

LimeNET Micro makes deploying wireless networks more accessible than ever before, by extending the LimeNET line of integrated hardware solutions via an ultra-low cost platform that is capable of supporting narrowband systems, such as GSM and IoT wireless standards, in a stand-alone configuration.

File:TBD.png

Figure 1. LimeSDR-Micro v2.1

LimeNET-Micro board features:

• RF transceiver
  • Lime Microsystems LMS7002M
• Raspberry Pi
  • DDR2 SODIMM socket for raspberry Pi CM3(L)
  • 2x downstream USB 2.0 ports
  • Upstream Micro-USB for USB boot of Compute Module
  • 3.5mm analog audio, composite video output
  • Ethernet + active PoE (RJ45) connector
  • Ribbon cable camera and display connectors
  • HDMI connector
  • External UART connector
  • uSD card slot
  • USB2.0 HUB and 10/100 Ethernet controller
  • SDIO Wi-Fi module
  • Jumper for Raspberry boot mode selection
• FPGA Features
  • Intel MAX10 10M16SAU169C8 device in 169-pin UBGA
  • 16K logic elements
  • 549 Kbits embedded memory (M9K) and 2368 Kbits of user Flash Memory
  • 45 embedded 18x18 multipliers
  • 1 PLLs
• FPGA Configuration
  • JTAG mode configuration
• USB Controller
  • FTDI FT601 USB to FIFO interface bridge chip (connects FPGA to USB2.0 HUB)
• Memory Devices
  • 4Mbit FLASH (for FPGA data)
  • 2x 128Kbit (16K x 8) EEPROM (for LMS MCU firmware and FPGA data)
• Other Devices
  • Temperature sensor
  • Crypto Authentication Device
  • GNSS receiver
• Connections
  • 2 x coaxial RF (SMA) connectors
  • SMA connectors for reference clock IN/OUT, GNSS and Wi-Fi antennas
  • 5V DC power jack
  • 5V header for powering external devices
  • Fan header
  • FPGA JTAG connectors (0.05” pitch and side connector)
  • Backup battery connector for GNSS receiver
• Clock System
  • 30.72MHz VCOCXO:
    • Frequency calibration ±0.5ppm;
    • Frequency stability over temperature in still air ±20ppb;
    • Frequency slope ΔF/ΔT in still air ±1.2ppb/°C
  • Possibility to tune VCOCXO by onboard DAC
  • Possibility to use GNSS PPS signal as a reference when tuning VCOCXO frequency
• User I/O
  • GPIO header (0.05” pitch) connected to FPGA
  • 5X dual color (RG) LEDs connected to FPGA
  • Push button connected to FPGA
  • Buzzer connected to FPGA
• Board Size: without connectors 125mm x 65mm (4.92” x 2.56”)

For more information on the following topics, refer to the respective documents:

• FT601 controller resources [link]
• MAX10 device family, refer to Intel documentation [link]
• LMS7002M transceiver resources [link]

Board Overview

LimeNET-Micro board version 2.1 picture with highlighted major components and connections presented in Figure 1 and Figure 2. Lime Microsystems LMS7002M RF transceiver and Intel MAX10 FPGA can be found on bottom side of board, DDR2 SODIMM socket for Raspberry PI Compute module is placed on top side. There are three connector types – data and debugging (USB2.0, FPGA GPIO, Ethernet and JTAG), power (DC jack and external supply pinheader), RF (clock source output, GNSS antenna and time pulse output, RF transmit and receive ports). LimeNET-Micro 2.1 board comes in three versions and each version differs in components which are fitted on board (BOM – Bill Of Material). BOM version can be determined from resistors R34, R35, R36, R37 fitted on board (see Figure 2 “BOM version resistors” and Table 1 for version description).

Table 1. BOM version description

BOM_VER	R34	R35	R36	R37	Comment
0	Fitted	Fitted	Fitted	Fitted	Lime (full version)
1	NF	Fitted	Fitted	Fitted	SDR (without duplexers and WiFi module)
2	Fitted	NF	Fitted	Fitted	GSM (with duplexers, without PoE, audio and video)

Figure 2. LimeNET-Micro top side components and connectors

Figure 3. LimeNET-Micro bottom side components

Board components description listed in the Table 2 and Table 3.

Table 2. Board components

Featured devices
Board Reference	Type	Description
IC1	RF transceiver	Lime Microsystems LMS7002M
IC14	GNSS module	GNSS receiver
IC12	FPGA	Intel MAX10, 10M16SAU169C8G, 169-UBGA
IC24	USB 2.0 HUB	Microchip Technology LAN9514 USB 2.0 Hub and 10/100 Ethernet Controller
IC27	USB to FIFO	FTDI FT601, USB to FIFO interface bridge
IC30	Wi-Fi	SDIO Wi-Fi module (WF111)
Miscellaneous devices onboard
IC13	IC	Temperature sensor LM75
IC20/21	IC	I2C secure key storage ATECC508A
Configuration, Status and Setup Elements
J3	JTAG chain pin header	FPGA programming pin header for Altera USB-Blaster download cable, side connection.
J4	JTAG chain pin header	FPGA programming pin header for Altera USB-Blaster download cable, 0.05” pitch
LED1, LED2, LED3, LED4, LED5	Red-green status LEDs	User defined FPGA indication.
LED6	Red-green status LEDs	VCC3P3 power rail indications
LS1	Buzzer	Buzzer (WST-1203UX), connected to FPGA.
J14	Jumper	USB boot mode jumper
J18	Jumper	External USB mode jumper
J27	Jumper	Power source selection
General User Input/Output
J5	Pin header	8 FPGA GPIOs plus 2 power pins, 0.05” pitch
SB1	Push button	Push button connected to FPGA
Memory Devices
IC3, IC16	EEPROM	128K (16K x 8) EEPROM connected to FPGA and LMS7002M
IC23	Flash memory	4Mbit FLASH memory connected to FPGA
Communication Ports and interfaces
J9	RJ45 connector	Ethernet + active PoE connector
J10	USB2.0 connector	2x downstream USB2.0 type A connectors
J11	Header	USB downstream header
J12	Header	Upstream USB2.0 header
J13	Socket	DDR2 SODIMM socket for Raspberry Pi CM3(L)
J15	USB2.0 connector	microUSB2.0 upstream connector
J17	Header	External UART header
J19	Connector	HDMI connector for display
J22	Connector	LVDS connector for display
J23	Connector	LVDS connector for camera

Table 3. Board components

Clock Circuitry
Board Reference	Type	Description
XO1	VCOCXO	30.72 MHz voltage-controlled crystal oscillator used as a reference clock.
XO2	VCTCXO	30.72 MHz voltage-controlled, temperature compensated crystal oscillator used as a reference clock.
XO3	VCTCXO	30.72 MHz voltage-controlled, temperature compensated crystal oscillator used as a reference clock. (Not fitted by default)
XO4	VCTCXO	40.0 MHz voltage-controlled, temperature compensated crystal oscillator used as a reference clock.
IC35 OR IC37	IC	Analog devices 16bit AD5662 or 8bit AD5601 Digital-to-analog converter for reference clock voltage control
IC36	IC	Phase detector (ADF4002)
J25	SMA connector	Reference clock input
J24	SMA connector	Reference clock output
RF connectors
J1	SMA connector	Transmit port or TRXA channel in duplex mode
J2	SMA connector	Receive port or TRXB channel in duplex mode
J7	SMA connector	GNSS module antenna connector
J20	SMA connector	Antenna connector for Wi-Fi module
Power Supply
J28	DC input jack	External 5V DC power supply input
J26	Pin header	5V DC power supply output header and main internal power rail
J6	Pin header	Backup battery connection header for GNSS module. Typical 3.0V (follow recommendation in fitted GNSS module datasheet)
Other
J16	Card slot	uSD card slot for Raspberry Pi boot
J11	Header	Fan connection header