This document describes the hardware architecture of the Emcraft Systems nRF9151 System-on-Module (referred to as “nRF9151 SOM” hereafter).

The nRF9151 SOM is intended to provide a low-cost flexible platform for embedded solutions that require rich connectivity and flexibility of the nRF9151 System-in-Package (SiP). The nRF9151 SOM is based on the NORDIC^® Semiconductor nRF9151 (SiP) supporting LTE-M, NB-IoT, GNSS and NR+. The Zephyr kernel and applications execute on the. The integrated peripheral controllers of the nRF9151 are used to implement various communication, connectivity and human-machine interfaces.

Using a miniature mezzanine form factor, the nRF9151 SOM is specifically designed to provide a battery-operated platform for cellular IoT on various boards targeting industrial automation, system and power management, wired and wireless networking / sensors and other embedded applications. The nRF9151 SOM is architected as a low-cost solution with flexibility in customizing its functionality for the needs of particular products and customers.

This section defines the hardware platform of the nRF9151 SOM.

The following are the key hardware features of the nRF9151 SOM:

•   Compact mezzanine module (30.5mm x 55mm);

•   External interfaces using two 50-pin 0.4mm-pitch connectors;

•   Two mounting holes reducing the risk of connector-to-PCB intermittence;

•   Compliant with the Restriction of Hazardous Substances (RoHS) directive;

•   NORDIC^® Semiconductor nRF9151 System-in-Package (SiP) with ARM^® Cortex^®-M33 64 MHz processor core;

•   SWD interface to the nRF9151 on the interface connectors;

•   Powered from a +5V power supply and/or a 1cell 3.7V rechargeable LiIon/Li-Po  battery;

•   Low-power operational modes with fast wake-up;

•   16MBytes SPI Flash memory;

•   On-module clocks;

•   nPM1300 PMIC for battery  charging and fuel gauging;

•   A 3.0V power output for external devices on the interface connectors;

•   2 software configurable power regulator outputs (1.0V-3.0V) up to 200mA in total on the interface connectors;

•   Output power for external devices: VSYS (from either VIN/VBUS or VBAT_C input) and VBUSOUT - available when VIN/VBUS is present

•   Serial console interface at the UART CMOS levels;

•   A Nano/4FF SIM card slot, supporting (e)SIM;

•   An optional MFFx M2M UICC SIM Card;

•   An I-PEX MHF1/u.Fl connector for a LTE antenna;

•   An I-PEX MHF1/u.Fl connector for a GNSS antenna;

•   An RF amplifier for GNSS;

•   A Real Time Clock;

• Various serial digital (UART, SPI, I2C, I2S, PWM, PDM) and analog interfaces of the nRF9151 available on the interface connectors.

The following figure is a functional block diagram of the on the interface connectors:

Open

The architecture of the nRF9151 SOM is built around the NORDIC Semiconductor nRF9151 SPI that combines the ARM^® Cortex^®-M33 64 MHz processor core with a wide range of the integrated peripheral controllers.

The nRF9151 contains a 1MB Flash memory and 236kB low leakage RAM.

The nRF9151 device is implemented using the 12.1mm x 11.1mm 0.5mm-pitch Map LGA package.

The nRF9151 SOM provides a two-pin SWD interface (the SWDIO and SWDCLK signals) on the interface connectors. This interface is routed to the corresponding signals of the nRF9151 device.

The nRF9151 is run from two power sources provided through multiple pins on the interface connectors:

• A USB Type C compliant +5V source (VIN/VBUS);

• A 1cell rechargeable Li-Po battery (VBAT_C/VBAT).

The power architecture of the nRF9151 SOM is based on the NORDIC Semiconductor nPM1300 PMIC, which has several power and system management features, including (refer to NRF9151 SOM Functional Block Diagram for a graphic view of circuit connections):

• System regulator (SYSREG) of the PMIC supplies main power rail VSYS from:

  •  VBUS (VIN from an AC wall adapter or a USB port- if/when they are present);

  • Battery (VBAT_C): when a battery is connected but VIN (VBUS) isn’t present;

• The VSYS voltage is 4V-5.5V when it is supplied from the VIN (VBUS) (+5V power is present) and 3.2V-4.4V when it is supplied from the Battery/VBAT_C (+5V power isn’t present)

  • Two 200mA BUCK regulators:

    • §  BUCK2 (VOUT2) @ 3.0V is used on the SOM and broken out to the SOM interface connectors;

    • §  BUCK1 is disabled by default, may be enabled and configured by software to a 1.0V-3.0V output voltage. It is available on SOM interface connectors;

  • Two LDO/Load Switches :

    • §  LDO1/LSW1 gets power from the BUCK1 output. LDO1/LSW1 is disabled by default, may be enabled and configured by software to a 1.0V-3.0V output voltage. It is available on the SOM interface connectors;

    • §  LDO2/LSW2 isn’t used in the nRF9151 SOM

• SYSREG provide the following features:

  • Operating voltage up to 5.5 V

  • Overvoltage protection to 22 V

  • Undervoltage detection

  • USB port detection and a current limiter to comply with the USB specification

  • Provides VBUSOUT voltage

• In the nRF9151 SOM, the nPM1300 supplies VBUSOUT voltage on the SOM interface connectors when VIN (VBUS) voltage is present. VBUSOUT provides overvoltage and undervoltage protection for safe connection to external devices.

• The nPM1300 supports the USB PD Configuration Channel functionality.

• The PMIC VIN (VBUS) input current limiter manages VIN (VBUS) current limitation and charger detection for USB Type-C compatible chargers. The VIN (VBUS) current limit value is configurable by software.

• The PMIC battery charger is suitable for general purpose applications with lithium-ion (Li-ion), lithium-polymer (Li-poly), and lithium iron phosphate (LiFePO4) batteries.

• nPM1300 supports charging up to 800 mA and delivers up to 500 mA of adjustable regulated voltage.