SRF NRM7292D Ultra Low Power and Long Range WiFi Module

NRM7292D Ultra Low Power and Long Range WiFi Module

Overview

IEEE 802.11ah is a new Wi-Fi standard operating in the Sub 1GHz license-exempt band, offering longer range and lower power connectivity necessary for internet of things (IoT) applications. NRM7292D contains external RF front end module (FEM) which can increase transmission power up to 23 dBm. Onboard serial flash can be used for OTA software development and with internal 32KB cache memory, it can support execution in place (XIP) feature.
Figure 1.1 NRM7292D pictures

Applications

Low to high data rate of NRM7292D can be applied in various IoT applications like:

  • Wearable
  • Home automation
  • Healthcare
  • Industrial automation
  • Safety and security
  • Smart grid
  • Multimedia streaming
NRM7292D module features

The main features of NRM7292D are represented as follows:

  • Standard
    • IEEE Std 802.11ahTM-2016 compliant
    • 1/2/4 MHz channel bandwidth support
    • WPA2 PSK support
    • 150 Kbps ~ 15 Mbps data rate
    • AP and STA role support
  • Radio frequency
    • 109 dBm minimum receive sensitivity
    • +23 dBm transmit power
    • 902~928 MHz frequency band (By replacing RF SAW filter, other frequency band can be supported within 750~950 MHz)
  • CPU
    • ARM Cortex-M3 for application
    • ARM Cortex-M0 for IEEE 802.11ah WLAN
    • Clock frequencies for both processor (32/48 MHz)
  • Host interface
    • UART and SPI support for host interface
  • Peripherals
    • GPIO, ADC, PWM and timers
    • I2C, SPI and UART

Pin Description

Figure 3.1 NRM7292D module pinout (top view)

Table 3.1 NRM7292D signal description

Pad No

Name Direction Volt Description
1 GROUND GND

2

GROUND GND
3 GROUND GND

4

GROUND GND
5 VDD_FEM P

Front End Module power input

6

VBAT P NRC7292 power input
7 GROUND GND

8

GROUND GND
9 MODE_00 I

SW Define (When ROM BOOT) 11: Internal SRAM BOOT

10

MODE_01 I

11

MODE_02 I

0: ROM BOOT
1: XIP BOOT

12

MODE_03 I

0: Cortex-M0 Master
1: Cortex-M3 Master

13

MODE_04 I

0: Two CPU
1: One CPU

14

GROUND

GND

15

HSPI_nCS I Host SPI – Chip Select (active low)
16 HSPI_CLK I

Host SPI – Clock

17

HSPI_MISO O Host SPI – Master in Slave out
18 HSPI_MOSI I

Host SPI – Master out Slave in

19

HSPI_EIRQ O Host SPI – Interrupt
20 GROUND GND

21

GROUND GND
22 NC

23

NC
24 NC

25

GP_00_UART2_TX I/O UART Channel2 Tx
26 GP_01_UART2_RX I/O

UART Channel2 Rx

27

GP_02_UART2_RTS I/O UART Channel2 RTS
28 GP_03_UART2_CTS I/O

UART Channel2 CTS

29

GP_04_UART0_TX I/O UART Channel0 Tx
30 GP_05_UART0_RX I/O

UART Channel0 Rx

31

GP_06_UART3_TX I/O UART Channel3 Tx
32 GP_07_UART3_RX I/O

UART Channel3 Rx

33

GP_08_UART1_RX I/O UART Channel1 Rx
34 GP_11_UART1_TX I/O

UART Channel1 Tx

35

GP_10_GPIO I/O Multiple purpose (GPIO,I2C,PWM,SPI, Ext-INT)
36 GP_09_GPIO I/O

37

GP_17_I2C_SDA I/O I2C_SDA
38 GP_16_I2C_SCL I/O

I2C_SCL

39

GP_15_SSP0_CLK O SPI0_Clock
40 PD_14_SSP0_CS O

SPI0_Chip Enable(active low)

41

PD_13_SSP0_MOSI O SPI0_Master out slave in
42 PD_12_SSP0_MISO I

SPI0_Master in Slave out

43

RESET I Reset (active high)
44 GROUND GND

45

JTAG_TRSTN I JTAG reset
46 JTAG_TMS I

JTAG mode selection

47

JTAG_TCK I JTAG clock
48 JTAG_TDI I

JTAG data input

49

JTAG_TDO O JTAG data output
50 GROUND GND

51

VDDIO P NRC7292 I/O supply Input
52 GROUND GND

53

GROUND GND
54 AUXADCIN3 I

AUXADC input 3

55

AUXADCIN2 I AUXADC input 2
56 AUXADCIN1 I

AUXADC input 1

57

GROUND GND
58 NC

59

NC
60 GROUND

GND

61

GROUND GND
62 RF_ANT I/O

RF IN/OUT

63

GROUND GND

64

GROUND GND

65 GROUND GND

66

GROUND GND

67

GROUND GND
68 GROUND GND

Antenna Connection

Antenna Connection

An external Antenna is connected through the SMA type connector. It’s connected to Pad # 62 (RF_ANT) of NRM7292D through the PCB trace of 50ohm impedance.

  • Antenna Requirements
  • Connection Type: External Antenna (SMA connector)
  • Frequency Range : 902~928MHz
  • Input Impedance: 50ohm
  • Gain: Ang 0dBi (Max <1.68dBi)

Please refer to NRM7292 EVK which use 900MHz Dipole Antenna as bellow
Figure 4.1 Antenna Connection on EVK

Operating Condition

Absolute Maximum Rating

Table 5.1 NRM7292D absolute maximum rating

Symbol

Min Max Unit
Storage Temperature -40 +125

Supply Voltage

VDD_FEM -0.5 5.25 V
VBAT -0.5 3.8

V

VDDIO

-0.5 3.8

V

  • NOTE : Stresses above those listed in Absolute Maximum Rating may cause permanent device Functionality at or above these limits is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability.
Operating condition

Table 5.2 NRM7292D operating condition

Symbol

Min Typ Max unit
Operating Temperature Range -40 +85

Operating Voltage

VDD_FEM 2.8 4.0 4.2 V
VBAT 2.8 3.3 3.6

V

VDDIO

1.8 3.3 VBAT V
  • NOTE : To ensure WLAN performance, ripple on the 2.1- to 3.3-V supply must be less than ±300 mV and ripple on the 1.8-V supply must be less than 2% (±40 mV).
Current consumption

Table 5.3 NRM7292D current consumption

MODE

 DUT Status Band (MHz) VDDIO (mA) VBAT (mA)

VDD_FEM (mA)

802.11ah (1/2/4Mhz BW)

Tx @ 17 dBm (VDD_FEM = 3.3V)

915 0.5 33 148
Tx @ 17 dBm (VDD_FEM = 4.0V) 0.5 33

153

Tx @ 20 dBm (VDD_FEM = 3.3V)

0.5 33 177
Tx @ 20 dBm (VDD_FEM = 4.0V) 0.5 33

184

Continuous Rx @ -80 dBm (VDD_FEM = 3.3V)

0.5 33 7
Continuous Rx @ -80 dBm (VDD_FEM = 4.0V) 0.5 33

7

Deep Sleep mode

0.6(uA) 27(uA)

0.4(uA)

  • Note: Unless otherwise specified, TA.=27℃, VBAT= 3.3V, 99% tx burst time, using internal PMU.
  • Power measurements are done at antenna port, which is directly connected to the device.
  • HSPI pins to host are disconnected.

11ah WLAN RF Specifications and Performance

Transmitter Specifications

Table 6.1 Transmitter Spec/Feature (RF)

Parameter

Conditions Min Typ Max Unit
RF Output Frequency Range (1) 902 928

MHz

EVM Compliant Output Power

15 Mbps (MCS7, 4 MHz BW) 20 dBm
EVM at 0 dBm output power -35

dB

Transmitter Spurious Signal Emissions

< 700 MHz <-36 dBm/ MHz
> 1 GHz <-45

RF Output Return Loss

Single ended output port -10 dB
Output 1dB Gain Compression 0.4 MHz CW signal input 27

dBm

Gain Control Range

30 dB
Gain Control Step 1

dB

Unwanted Sideband

Over RF channel, RF frequency, and baseband frequency at 0 dBm output power <-40

dBc

  • Note: Unless otherwise specified, TA.=27℃, VBAT=2.6 to 3.6V, VDD_FEM=4.0V. RF input/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit OCB and SMA
    (1) RF output frequency range depends on RF SAW filter on the module. The NRC7292 chipset by itself can support frequency range from 750 to 950 MHz.
Receiver Specifications

Table 6.2 Receiver Spec/Feature (RF)

 

Parameter

Conditions Min Typ Max Unit
RF Input Frequency Range (1) 902 928

MHz

RF Input Return Loss

For LNA high/mid/low gain modes -10 -12 -15 dB
Total Voltage Gain Range Analog + Digital Gain -10 92

dB

RF Gain Step

From high gain mode to medium gain mode 6

dB

RX Gain Step

From RF to Analog 1

dB

DSB Noise Figure

LNA max gain mode 3.5

dB

IIP3

LNA with high gain mode -17  

dBm

LNA with low gain mode 24

Baseband Filters for Receiver (Analog + Digital Filter)

Baseband -3dB Low-pass Corner Frequency (Controllable) 1 MHz channel 0.5 MHz
2 MHz channel 1.0

MHz

4 MHz channel

2.0

MHz

  • Note: Unless otherwise specified, TA.=27℃, VBAT=2.6 to 3.6V, VDD_FEM=4.0V. RF input/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit OCB and SMA
    (1) RF input frequency range depends on RF SAW filter on the module. The NRC7292 chipset by itself can support frequency range from 750 to 950 MHz.
Transmitter Performance

DR/MCS/BW (Mbps/ /MHz)

IEEE Relative constellation error (dB) EVM (%) (IEEE) EVM (%)(NRM7292D)

 Comments

0.15/MCS10/1

-4 63.1 3.0 BPSK Peak
0.30/MCS0/1 -5 56.2 3.0

BPSK Peak

0.60/MCS1/1

-10 31.6 3.0 18 dBm OFDM, RMS
0.90/MCS2/1 -13 22.4 3.0

18 dBm OFDM, RMS

1.20/MCS3/1

-16 15.8 3.0 18 dBm OFDM, RMS
1.80/MCS4/1 -19 11.2 3.0

18 dBm OFDM, RMS

2.40/MCS5/1

-22 7.9 3.0 18 dBm OFDM, RMS
2.70/MCS6/1 -25 5.6 3.0

18 dBm OFDM, RMS

3.00/MCS7/1

-27 4.5 3.0 18 dBm OFDM, RMS
0.65/MCS0/2 -5 56.2 3.2

BPSK Peak

1.30/MCS1/2

-10 31.6 3.2 18 dBm OFDM, RMS
1.95/MCS2/2 -13 22.4 3.2

18 dBm OFDM, RMS

2.60/MCS3/2

-16 15.8 3.2 18 dBm OFDM, RMS
3.90/MCS4/2 -19 11.2 3.2

18 dBm OFDM, RMS

5.20/MCS5/2

-22 7.9 3.2 18 dBm OFDM, RMS
5.85/MCS6/2 -25 5.6 3.2

18 dBm OFDM, RMS

6.50/MCS7/2

-27 4.5 3.2 18 dBm OFDM, RMS
1.35/MCS0/4 -5 56.2 3.0

BPSK Peak

2.70/MCS1/4

-10 31.6 3.0 18 dBm OFDM, RMS
4.05/MCS2/4 -13 22.4 3.0

18 dBm OFDM, RMS

5.40/MCS3/4

-16 15.8 3.0 18 dBm OFDM, RMS
8.10/MCS4/4 -19 11.2 3.0

18 dBm OFDM, RMS

10.80/MCS5/4

-22 7.9 3.0 18 dBm OFDM, RMS
12.15/MCS6/4 -25 5.6 3.0

18 dBm OFDM, RMS

13.50/MCS7/4

-27 4.5 3.0

18 dBm OFDM, RMS

  • Conditions: supply voltage VBAT=2.6 ~ 3.6V, VDD_FEM=4.0V, Ta=25℃, signal within spectrum
Receiver Performance

Receiver Sensitivity
Table 6.4 Sensitivity (minimum input level)

Band

BW Rate Modulation/Coding Rate Conditions Chip Port Specification [dBm]
kbps Min Typ

Max

902~ 928MHz 1 MHz

300

BPSK 1/2 @ PER<10%, 256 bytes Full Operating Temperatures Battery Voltage Range;
Load Z : 50 Ohms;
-106
600 QPSK 1/2 -104

900

QPSK 3/4 -101
1200 16QAM 1/2 -98

1800

16QAM 3/4 -95
2400 64QAM 2/3 -91

2700

64QAM 3/4 -90
3000 64QAM 5/6

-88

150

BPSK 1/2 rep. 2x -109
2 MHz

650

BPSK 1/2

@ PER<10%, 256 bytes Full Operating Temperature; Full Battery Voltage Range; Load Z : 50 Ohms;

-100

1300

QPSK 1/2 -98
1950 QPSK 3/4

-97

2600

16QAM 1/2 -94
3900 16QAM 3/4

-91

5200

64QAM 2/3 -86
5850 64QAM 3/4

-85

6500

64QAM 5/6 -83
4 MHz 1350 BPSK 1/2 @ PER<10%, 256 bytes Full Operating Temperature; Full Battery Voltage Range; Load Z : 50 Ohms;

-99

2700

QPSK 1/2 -97
4050 QPSK 3/4

-94

5400

16QAM 1/2 -91
8100 16QAM 3/4 -88

10800

64QAM 2/3 -83
12150 64QAM 3/4

-82

13500

64QAM 5/6

-80

Adjacent Channel Rejection (ACR)

Band

BW Rate Modulation/Coding Rate Conditions ACR [dB]
kbps Min Typ

Max

902~ 928MHz

1 MHz

300

BPSK 1/2 @ PER<10%, Pdesired=Psensitivty + 3dB, Pinterfere]@ N+1 channel 36
600 QPSK 1/2 34

900

QPSK 3/4 31
1200 16QAM 1/2 28

1800

16QAM 3/4

26

2400

64QAM 2/3 22
2700 64QAM 3/4

20

3000

64QAM 5/6 19
150 BPSK 1/2 rep. 2x

39

 

 

 

 

2 MHz

650

BPSK 1/2 @ PER<10%, Pdesired=Psensitivty + 3dB, Pinterfere]@ N+1 channel 32
1300 QPSK 1/2

31

1950

QPSK 3/4 30

2600

16QAM 1/2

27

3900 16QAM 3/4

24

5200

64QAM 2/3 21
5850 64QAM 3/4

20

6500

64QAM 5/6

19

4 MHz

1350

BPSK 1/2 @ PER<10%, Pdesired=Psensitivty + 3dB, Pinterfere]@ N+1 channel 32
2700 QPSK 1/2

29

4050

QPSK 3/4 28
5400 16QAM 1/2

25

8100

16QAM 3/4

22

10800 64QAM 2/3

20

12150

64QAM 3/4

17

13500

64QAM 5/6

15

Packing Specification

Dimensions of Tape

Figure 7.1 Tape information

Taping Diagrams

Figure 7.2 Device orientation on tape

Box Information

Figure 7.3 Box dimension

Label Information
  • Reel / AL Bag / Inner Box

Figure 7.4 Label information

Packing Process

Figure 7.5 Packing process

SMT Temperature Sequence (Pb-free)

Figure 8.1 Reflow profile

Revision History

Revision No

Date Comments
Ver 1.0 7/27/2022

Initial version for customer release created

FCC Compliance Statement

This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

FCC Interference Statement

This equipment has been tested and found to comply with the limits for a Class B  digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to correct the interference by one of the following measures:

  • Reorient or relocate the receiving antenna.
  • Increase the separation between the equipment and receiver.
  • Connect the equipment into an outlet on a circuit different from which the receiver is connected.
  • Consult the dealer or an experienced radio/TV technician for help
FCC Caution

Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate this equipment. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.

FCC Radiation Exposure Statement

This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20 cm between the radiator and your body. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.

Information on test modes and additional testing requirements

a) The modular transmitter has been fully tested by the module grantee on the required number of channels, modulation types and modes, it should not be necessary for the host installer to retest all the available transmitter modes or settings. It is recommended that the host product manufacturer installing the modular transmitter, perform some investigative measurements to confirm that the resulting composite system does not exceed the spurious emissions limits or band edge limits(e.g., where a different antenna may be causing additional emissions).
b) The testing should check for emissions that may occur due to the intermixing of emissions with the other transmitter, digital circuitry, or due to physical properties of the host product(enclosure).
This investigation is especially important when integrating multiple modular transmitters where the certification is based on testing each of them in a standalone configuration. It is important to note that host product manufactures should not assume that because the modular transmitter is certified that they do not have any responsibility for final product compliance.

Additional testing, Part 15 subpart B disclaimer

The final host/module combination need to be evaluated against the FCC Part 15B criteria for unintentional radiators in order to be properly authorized for operation as a Part 15 digital device.

The host integrator installing this module into their product must ensure that the final composite product complies with the FCC requirements by a technical assessment or evaluation to the FCC rules, including the transmitter operation and should refer to guidance in KDB 996369.

This appliance and its antenna must not be co-located or operation in conjunction with any other antenna or transmitter.

  • OEM integrators must ensure that its product is electrically identical to the device, FCC ID: 2A32R-NRM7292D reference designs . Any modifications to module reference designs may invalidate regulatory approvals in relation to the product, or may necessitate notifications to the relevant regulatory authorities.
  • OEM integrators are responsible for regression testing to accommodate changes to designs, new antennas, and host and submit for C2PC filings.
  • Colocation with other transmitter modules will be addressed through filings for those co-located transmitters when necessary or that colocation of other transmitters will be according to applicable KDB guidelines including those for RF exposure
  • Appropriate labels must be affixed to the product that complies with applicable regulations in all respects. The regulatory label on the final system must include the statement:
    “Contains FCC ID: 2A32R-NRM7292D”.
  1. The module is limited to OEM installation ONLY.
  2. OEM integrators are responsible for ensuring that the end-user has no manual instructions to remove or install module.
  3. The module is limited to installation in mobile or fixed applications, according to Part 2.1091(b).
  4. Separate approval is required for all other operating configurations, including portable configurations with respect to Part 2.1093 and different antenna configurations.
End Product Labeling

The module is labeled with its own FCC ID. If the FCC ID is not visible when the module is installed inside another device, then the outside of the device into which the module is installed must also display a label referring to the enclosed module. In that case, the final end product must be labeled in a visible area with the following:
“Contains FCC ID: 2A32R-NRM7292D

SRF-Logo.png

Documents / Resources

SRF NRM7292D Ultra Low Power and Long Range WiFi Module [pdf] User Manual
NRM7292D, 2A32R-NRM7292D, 2A32RNRM7292D, NRM7292D Ultra Low Power and Long Range WiFi Module, Ultra Low Power and Long Range WiFi Module, Low Power and Long Range WiFi Module, Long Range WiFi Module, WiFi Module, Module

References

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