Comparison between AS3992 and R2000 Detailed explanation of performance differences between AS3992 and R2000

This article mainly introduces the comparison between AS3992 and R2000, and describes the differences in performance and characteristics between AS3992 and R2000 in detail.

AS3992

UHF RFID reading chip, the receiving sensitivity reaches -86DB, and supports IEC 18000-6B communication protocol. Available in a 64-pin QFN package (9mm x 9mm). The integration level of the chip is very high. At the transmitting end, it mainly integrates phase-locked loop, voltage-controlled oscillator, mixer, modulator and power amplifier circuit. It also supports the digital part of protocol processing. In order to meet different needs, users can also pass Programming selects an external amplifier circuit; the receiving end mainly integrates a low noise amplifier, a mixer, an intermediate frequency amplifier and a demodulation circuit; in addition, in order to reduce power consumption, the chip supports a variety of power consumption modes, and can also be used for external controllers and Other components provide a voltage of 1.5 ~ 3.3V; optional protocol processing unit, etc., which greatly simplifies the design of RF peripheral circuits, and the internal protocol processing also greatly facilitates application development.

chip

As shown in the figure, the chip is mainly divided into a radio frequency module and an MCU interface module, and the radio frequency chip communicates with the microcontroller through a serial port or a parallel port to receive and execute instructions from the microcontroller. When transferring data, data or instructions are written to the 24b fif0 register through the MCU interface module. The data on the chip undergoes a series of processing, including assembling the frame according to the ISO/iec_18000-6c communication protocol, adding the frame header and CRC check code, encoding, modulation and amplification. According to needs, you can also choose_external power amplification. Finally, the radio frequency analog-to-digital conversion process is radiated outward through the antenna, and the decoded data is processed in the single-chip microcomputer, and some matters and OSCO are connected to a 20MHz crystal oscillator.

R2000

The R2000 chip is a high-performance UHF frequency band UHF reader chip, which integrates analog front-ends such as mixers, gain filters, voltage-controlled oscillators, phase-locked loops, analog-to-digital/digital-to-analog converters, and Built-in complete protocol processing system of ISO/IEC 18000 6C. The external controller can realize all communication and control of the R2000 chip only through the 8-bit parallel port or SPI port.

The communication frequency of UHF carrier signal is 840 MHz~960 MHz. The R2000 chip integrates VCO, prescaler, main divider, reference divider, phase detector and charge pump. The peripheral circuit only needs to provide a loop filter A complete phase-locked loop (PLL) circuit can be formed. The output frequency of the PLL is determined by the product of the set value of the reference divider and the main divider. The main role of the charge pump (CP) is to convert digital logic pulses into analog currents. The CP signal is fed back to the VCO pin through a low-pass filter to adjust the oscillator frequency accuracy. In order to obtain a stable VCO tuning voltage, the external loop filter circuit is particularly important. It plays a role in maintaining loop stability, controlling loop band internal and external noise, preventing VCO tuning voltage control line voltage mutation, and suppressing reference sideband spurious interference. and other important roles.

r2000 chip performance parameters

1. Main features

Label protocol: support IS018000-6C protocol

Working frequency: US frequency 902~928MHz (FCC part15)

2. China frequency 920~925MHz

System architecture: adopt the industry's most advanced dedicated radio frequency chip R2000, high integration, stable and reliable radio frequency performance

Output power: software adjustable, step interval 1.0dB, up to 30dBm

Reading distance: 9 meters (external 6dBiL antenna, label is E41)

Antenna connection port: 4 MMCX-J type RF connectors

GPIO interface: 3 (reserved function: optional input and output)

UART port: 1, baud rate 115200bps

USB port: One USB2.0 full speed port (12Mbit/sec)

Volume: 43X69X10.5mm (including shielding cover and heat sink)

Power supply: 5VDC

Current Consumption: 1. 5A peak @ 5V (depending on output power)

Working temperature: -20°C~ 55°C

R2000 chip pin introduction

Comparison between AS3992 and R2000

1. Comparison of receiving sensitivity: The receiving sensitivity of R2000 can reach -110dBm ideally under the condition of single reader, and can reach -95dBm under DRM (multi-reader), and in the case of DRM+10dBm carrier leakage, both It can reach -84dBm, and AS3992 can reach -86dBm ideally in a single reader. When lna is configured as -86dBm, the Tag is attached to the antenna, and the front end of AS3992 will be saturated immediately. R2000 seems to be slightly stronger in terms of dense label reading.

2. SJC: This is the root of R2000, currently no other reader chip has this function, powerful! !

3. Protocol: Both support 6B and 6C, but AS3992 supports 6A, and R2000 supports iP-X

4. Protocol integrity: This is essentially different from point 3. Take 6C as an example, both support it, but R2000 supports it much more completely. AS3992 has not done many details, at least the original demo firmware does not. And the R2000 is much better.

5. Chip analog front-end RF performance: This R2000 is doing very well. I remember that I once disconnected the Rx input, and it was actually able to inventory, although the RSSI reading was only about -90dBm. In fact, the most difficult part of the reader chip is to simulate the RF performance of the front end. With the giant intel, impinj has obvious advantages.

The main difference between 3992 and R2000 lies in three points

1. One is that the R2000 starts sjc processing in the RF frequency range, which is not available in the 3992.

2. In the if frequency band, both R2000 and as3992 have carried out related similar processing. But from the internal schematic diagram of their chip, the R2000 control is more detailed.

3. The speed of the R2000 interface seems to be faster than that of the as3992.

So on the whole, R2000 is better than AS3992 in performance.

As for the anti-collision algorithm:

1. This must be based on the quality of the RF analog part. In other words, if there is a gap in the radio frequency quality, it will definitely affect the anti-collision installation algorithm.

2. In addition, it is the influence of the algorithm and the MCU.

support service

1. R2000 is much worse than 3992. 

2. 3992 is easier to use and less difficult to develop than R2000