NXP PEPS solution in simple terms (1)-System structure and selection

    Taking the keyless entry of a car as an example, the following figure (1) is its development history. We can see that the car key has developed from a simple mechanical key to the addition of chip anti-theft to the current new type of smart key, which has been developing towards miniaturization, multi-function, and personalization.

Figure (1) The historical data of the keyless development of automobiles comes from the Gestapo Automobile Research Institute.

     Abstract the above development history into the trend of successful performance changes, as shown in Figure (2) below.:

Figure (2) Keyless car development trend

    Next, this article will focus on the three mainstream implementation methods to introduce the PEPS system, including: radio frequency scheme, Bluetooth scheme + NFC scheme, and UWB. And take the NXP solution, the chip supplier with the largest market share in the world, as an example as a reference for selection.

1. RF solution

    The traditional radio frequency solution consists of a controller, a radio frequency (RF) transmitter in the smart key, and a receiver on the car side. When the key is within the effective range, the owner pulls the car door or presses a key to start the switch, the corresponding module will send an interrupt signal to wake up the main controller and start the entire communication process. The whole process does not require the use of a key to open the car door or start the engine.

Figure (3) A simple structure diagram of the traditional radio frequency scheme. The data comes from the Gestalt Automobile Research Institute.

    Judging from the mainstream models on the market, the main anti-theft methods are achieved by radio frequency, including engine anti-theft locking system (IMMO is immobilization), remote control door lock (RKE is RemoteKeyless Entry), keyless access control (PKE is Passive Keyless Entry/GO). At present, IMMO and RKE are the most widely used, and the new PKE, welcome and other functions are more popular with users.

    The following figure (4) shows the application scenario described by the original NXP factory

Figure (4) The application scenario described by the original NXP factory

    Based on this application scenario and customer needs, the block diagram of the Total Solution solution provided by WPI Jinping Group based on the NXP chip is as follows：

Figure (5) WPI is based on NXP Total Solution block diagram

    The program has IMMO, PKE, RKE and other functions, and can read RSSI values in different ways in real time.

    Selection recommendation：

1. IMMO & LF Driver

    The following is the current NXP main promotion plan：

Figure (6) Basic functional structure of NXP IMMO & LF Driver

①: The ABIC series has IMMO function. It integrates all the functions necessary for the repeater to read and write, and uses a unique AM/PM demodulation technology that can automatically adjust the sampling time to effectively expand the operating range of the system. It has programmable clock division, modulation, reception gain and filter, and fast write-and-read-out reception setting characteristics.

It is recommended to be used in the electric motorcycle market, which is cost-effective.

②: JOKER NJJ29C0 series is the main product number of NXP in the keyless car, integrating IMMO+LF Driver function, its characteristics are as follows：

Figure (7) NJJ29C0 Characteristics

    Recommended application scenarios: advanced car keyless entry, LF+IMMO.

       ：: CENDRIC NJJ29C2 series is an upgraded version of NJJ29C0. It mainly improves the LF drive current (2.5A peak current in High-power-driver mode), LF channels are optional (the number of LF channels is divided into 5, 7, and 9 according to the different suffix), and supports two IMMOS.

    Recommended application scenario: advanced car keyless entry.

    Due to NXP NDA management, please contact a WPI technician for more details.

1. UHF

    UHF is divided into TRx and Rx, of which Rx is placed in the base station part and is used to receive the key signal. The mantra in TRx is placed at the key terminal, and MANTRA/CS is placed at the base station terminal, which is used to send signals to the base station and receive signals from the base station.

Figure (8) NXP UHF mainly promotes UHF solutions

①：Mantra Family TRx 主要包括三颗料号，基本特点如下

MantraC (NCK2983): 3 Rx parallel reception + 1 Tx

MantraCS (NCK2982): 1Rx serial reception + 1 Tx

MantraF (NCF2984): Keyfob application: 1 Rx + 1 Tx

推荐应用场景：先进汽车无钥匙进入、TPMS(胎压侦测)、Bi-Di Communication(双向通信)

 
② ：Sparc Cobra Rx

Sparc (NCK2913): 3 Rx parallel reception

Cobra (NCK2912): 1Rx serial reception

Recommended application scenarios: applications for receiving radio frequency information (which can be developed independently), such as TPMS base station terminals.

③：Lizard Basic Rx

Lizard (NCK2910): 1 Basic Rx

Recommended application scenarios: low-cost, low-difficulty software development applications.

    The above is the main product of NXP UHF. Due to the management of NXP NDA, please contact the WPI technician for more details.

1. Key or Tag（Token Family）

    At present, the key terminals of NXP's main solutions are divided into two categories: integrated and separate.

       ①: Integrated

       Tokens: NCF29A1, A2 (A1 supports 3D antenna, A2 supports 1D antenna)

       Token Plus: NCF29A7, A8

       Token SRx: NCF29AA, AB

       Token SRx2：NCF29AE

       The above series is mainly improved from top to bottom in the following aspects：

• Sensitivity (120 µVpp Wake-up sensitivity @6.6µA)
• Wake-up pulse time (6.1ms short WUP)
• RSSI(Narrow Band)
• Number of GPIOs (Up to 15)
• EROM(Up to 64K)
• LF baud rate (4K)
• Packge(HVQFN32 to HVQFN40)

The parameters in brackets above are the reference parameters of the new product. Due to NDA reasons, the specific details are not convenient to disclose. If necessary, please contact the WPI technical staff.

Recommended application scenario: high-frequency one-way smart key, of which NCF29A1 has a better price/performance ratio in terms of electric motorcycle.

       ②: Separate type

       ACTIC_active：NCF2953 (ACTIC 5G/3D) / NCF2954 (ACTIC 5G/1D)

       Mantra Family TRx: The above UHF is mentioned, Mantra (NCF2984)

       Recommended application scenario: two-way communication, high-end digital key.

       The above is the basic description of NXP Token Family.

Summary：

In summary, NXP's original RF solutions for PEPS have a wealth of products and very detailed classifications, which can be tailored to different needs for customers. Moreover, NXP has been at the forefront of the PEPS market, continuously improving product characteristics, continuously laying out, and striving for long-term development.

WPI World Peace Group is one of NXP's most important partners, and the two parties continue to cooperate. WPI launched the NXP PEPS Total Solution in "Datong". The block diagram of the solution is as follows. For detailed information or to purchase a Demo (including schematic diagram, PCB, program demo, test report, etc.), please click on the link below.：

https://www.wpgdadatong.com/IotNewsDetail?PID=0566#

Figure (9) WPI Total Solution

1. Bluetooth+NFC solution

With the development of Bluetooth and NFC technology, mobile phones and cards have gradually entered people's vision through Bluetooth or NFC technology as car keys.

Tesla released Moduel3 in the United States. The car does not come standard with a car key (if you want a car key, you need to pay an additional fee). Instead, the mobile phone app uses Bluetooth to drive, drive the trunk and other operations. If the phone is out of power, then the NFC function included with the phone can also realize the function. At present, the car has entered the Chinese market in November 2019. In addition, Tesla also equipped the owner with a spare key card, as shown in the figure below.：

 Picture (10) Tesla mobile APP picture (11) Tesla key card

After the mobile phone has become a car key, more convenient functions have been developed. As shown in the figure below (12), SAIC Roewe ei6 uses Bluetooth as the car key APP. In addition to being able to remotely unlock, lock, open the trunk and find the car through Bluetooth, it also has the function of borrowing a car, and canSet the limited time and permissions for borrowing a car in detail.

Figure (12) SAIC Roewe ei6 MOBILE APP

Based on market demand, WPI launched a Bluetooth+NFC solution based on NXP KW36+NCF3320. For detailed information, please refer to the Datong link (schematic diagram, PCB, program demo, test report, etc.)：

https://www.wpgdadatong.com/IotNewsDetail?PID=5211

The program has both Bluetooth and NFC functions, and can be combined with the development tools provided by NXP to send information to the program demo through the mobile phone Bluetooth, and can read RSSI data; the status is controlled through NFC to realize the start, stop, alarm and other functions. The block diagram and demo of the program are shown in Figure (13).：

图(13) WPI 蓝牙+NFC 方案框图及 Demo

 选型推荐：

①：蓝牙 主推 NXP KW35/36A

       KW36A 基本特点如下：

• Arm® Cortex®-M0+ running up to 48 MHz

• 256kB Program Flash + 256kB FlexNVM both with ECC; 64 kB SRAM; 8 KB EEPROM
• 2xSPI,2x LP-UART with LIN, CAN-FD; 2xI2C, CMT, GPIO with IRQ capability (KBI)
• Normal: 1.71V to 3.6V
• 16-bit Analog-to-Digital Converter (ADC)
• 6-bit High Speed Analog Comparator (CMP)

另外 KW36A 有多种尾缀可供选择，其对比如下图(14)：

图(14) MKW36/35 基本信息对比

       ②：NFC 主推 NXP NCF3320

       NCF3320 特点：

• AEC-Q100 qualified
• Read/write mode supporting：ISO/IEC 14443A/MIFARE、ISO/IEC 14443B、JIS X 6319-4 (comparable with FeliCa1、ISO/IEC 15693、ICODE EPC UID/ EPC OTP、ISO/IEC 18000-3 mode 3/ EPC Class-1 HF
• Interfaces：SPI,UART,I2C
• Low Power Card Detection
• 3 V to 5.5 V power supply
• FIFO buffer with size of 512 bytes for highest transaction performance

以上为蓝牙+ NFC 应用实例和参考选型，因原厂 NDA 原因，更多详细资料请联系本文作者或 WPI 技术窗口。

1. UWB

Ultra Wide Band (UWB) technology is a kind of wireless carrier communication technology. It does not use sinusoidal carriers, but uses nanosecond non-sinusoidal wave narrow pulses to transmit data, so it occupies a wide spectrum range. UWB technology has the advantages of low system complexity, low power spectral density of transmitted signals, insensitivity to channel fading, low interception ability, and high positioning accuracy. It is especially suitable for high-speed wireless access in dense and multipath places such as indoor.

At present, NXP-BWM-CONTI-Apple is jointly developing the UWB specification with IEEE, and there will be no compatibility issues between the subsequent NXP solution and Apple. More customers can also join in in the future. Judging from the development history at the beginning of this article, UWB is likely to become a mainstream trend in the future.

Selection recommendation：

NCJ29D5 (Ranger 4), the basic characteristics are as shown in the figure below (15)：

Figure (15) NCJ29D5 basic information

Recommended application scenarios: ①Car Access ② anti-relay ③ Driver breathing and heartbeat detection in the car替代 Replace ultrasonic radar.

summary：

     The above is the entire content of this blog post, which mainly describes several implementation methods and development trends of the current keyless entry system, as well as the program resources currently owned by WPI. Everyone is welcome to discuss together. The next issue of the blog post will focus on different solutions (PKE/RKE, Bluetooth, NFC, WUB) to talk about the tools needed for development and how to obtain the relevant resources of the original factory.

Remarks：

The pictures of this blog post come from <url>, NXP's original official website and WPI technical personnel. If you have any questions, please let the author know.

Reference document：

①NXP SCA Roadmap "Classic Car Access Sep 2019 v1.0"

②NXP Datasheet "MKW36A512"

③ "The Historical Process of NXP Car Key Chip"

④ "Family Application Notes-keyFOB"

⑤ "NCJ29D5 (Ranger4)"

⑥ "NCF3340_I2C_data_sheet"

DatDatasheet "NCF3320"