原标题：APC320 Si4463无线数传模块

　　APC320模块是高度集成低功耗半双工小功率无线数据传输模块，其嵌入高速低功耗单片机和高性能射频芯片SI4463，采用高效的循环交织纠检错编码，抗干扰和灵敏度都大大提高，APC320模块提供了多个频道的选择，可在线修改串口速率，收发频率，发射功率，射频速率等各种参数。

　　APC320支持点对点、点对多点应用，相应的组网版本支持MESH网络组网(参见相关产品简介)，其超高性能适用于高性能、高可靠智能电表无线抄表，APC320所支持的频率覆盖整个Sub-1GHz，各频段性能均处于业界领先水平，模块工作电压为2.1-3.6V，可定制3.5-5.5V工作电压，在接收状态下仅消耗15mA。APC320模块四种工作模式，各模式之间可任意切换，在1SEC周期轮询唤醒省电模式下，接收仅仅消耗几十uA，一节3.6V/3.6AH时的锂亚电池可工作数年，非常适合电池供电的系统。

　　APC320的组网版本APC320N组网模块。

　　特点：

　　2000米传输距离

　　工作频率470-510MHz

　　100mW发射功率(可设置)

　　接收灵敏度-115dBm@10Kbps

　　调制方式GFSK

　　多频道可设, 收发256Bytes数据缓冲区

　　工作电压4.5-5.5V

　　电流消耗 16mA(接收), 100mA(发射)

　　内置看门狗

　　尺寸 32.1*18.3*7.0(mm)

　　应用：

　　高性能、高可靠无线数传、通信、控制、计量系统

　　无线抄表, 智能电表无线手抄、组网集抄系统

　　各种替代RS232、RS485、MODBUS的应用场合

　　各种电力仪器仪表通讯、测量监测管理

　　各种物流、工矿、石油信息管理监测系统

　　城市LED屏幕, 路灯控制, 风光互补照明、供电系统

　　工业自动化控制、遥控、遥测、数据采集

　　智能家居、安防、楼宇、小区、公共设施自动化

【Si4463】

Features

▪ Frequency range = 142–1050 MHz

▪ Receive sensitivity = –129 dBm

▪ Modulation

》(G)FSK, 4(G)FSK, (G)MSK

》OOK

▪ Max output power

》+20 dBm (Si4463)

》+16 dBm (Si4461)

》+13 dBm (Si4460)

▪ PA support for +27 or +30 dBm

▪ Low active power consumption

》10/13 mA RX

》18 mA TX at +10 dBm (Si4460)

▪ Ultra low current powerdown modes

》30 nA shutdown, 40 nA standby

▪ Preamble sense mode

》6 mA average RX current at

1.2 kbps

》10 µA average RX current at

50 kbps and 1 sec sleep interval

▪ Fast preamble detection

》1 byte preamble detection

▪ Data rate = 100 bps to 1 Mbps

▪ Fast wake and hop times

▪ Power supply = 1.8 to 3.8 V

▪ Excellent selectivity performance

》69 dB adjacent channel

》79 dB blocking at 1 MHz

▪ Antenna diversity and T/R switch control

▪ Highly configurable packet handler

▪ TX and RX 64 byte FIFOs

》129 bytes dedicated Tx or Rx

▪ Auto frequency control (AFC)

▪ Automatic gain control (AGC)

▪ Low BOM

▪ Low battery detector

▪ Temperature sensor

▪ 20-Pin QFN package

▪ IEEE 802.15.4g and WMBus compliant

▪ Suitable for FCC Part 90 Mask D, FCC

part 15.247, 15,231, 15,249, ARIB T-108,

T-96, T-67, RCR STD-30, China

regulatory

▪ ETSI Category I Operation EN300 220

Applications

Smart metering (802.15.4g and WMBus)

▪ Remote control

▪ Home security and alarm

▪ Telemetry

▪ Garage and gate openers

▪ Remote keyless entry

▪ Home automation

▪ Industrial control

▪ Sensor networks

▪ Health monitors

▪ Electronic shelf labels

Description

Silicon Laboratories' Si446x devices are high-performance, low-currenttransceivers covering the sub-GHz frequency bands from 142 to 1050 MHz. Theradios are part of the EZRadioPRO® family, which includes a complete line oftransmitters, receivers, and transceivers covering a wide range of applications. Allparts offer outstanding sensitivity of –129 dBm while achieving extremely lowactive and standby current consumption. The Si4463/61/60 offers frequencycoverage in all major bands. The Si446x includes optimal phase noise, blocking,and selectivity performance for narrow band and wireless MBus licensed bandapplications, such as FCC Part90 and 169 MHz wireless Mbus. The 69 dBadjacent channel selectivity with 12.5 kHz channel spacing ensures robustreceive operation in harsh RF conditions, which is particularly important for narrowband operation. The Si4463 offers exceptional output power of up to +20 dBmwith outstanding TX efficiency. The high output power and sensitivity results in anindustry-leading link budget of 146 dB allowing extended ranges and highly robustcommunication links. The Si4460 active mode TX current consumption of 18 mAat +10 dBm and RX current of 10 mA coupled with extremely low standby currentand fast wake times ensure extended battery life in the most demandingapplications. The Si4463 can achieve up to +27 dBm output power with built-inramping control of a low-cost external FET. The devices can meet worldwideregulatory standards: FCC, ETSI, wireless MBus, and ARIB. All devices aredesigned to be compliant with 802.15.4g and WMbus smart metering standards.

The devices are highly flexible and can be configured via the WirelessDevelopment Suite (WDS) available on the Silicon Labs website.

Si446x/Si4362 RX LNA Matching

1. Introduction

The purpose of this application note is to provide a description of the impedance matching of the RX differential low

noise amplifier (LNA) on the Si446x/Si4362 family of RFICs.

It is desired to simultaneously achieve two goals with the matching network:

▪Match the LNA input to the antenna source impedance (e.g., 50 

▪Provide a single-ended-to-differential conversion function (i.e., a balun)

The matching procedure outlined in this document provides for achieving the goals listed above.

For those users who are not interested in the theoretical derivation of the match network, but are just concerned

with quickly obtaining matching component values, refer to the Summary Tables shown in "4.1.7. Summary Tables

of 3-Element Match Network Component Values vs. Frequency" on page 12 and "4.2.7. Summary Tables of 4-

Element Match Network Component Values vs. Frequency" on page 19.

Measurements were performed on the Si4461-B0 chip but are applicable to other members of the Si446x family of

chips (e.g. Si446x-B1, C0, C1, C2 and the Si4362 chip).

2. Match Network Topology

The LNA on the Si446x/Si4362 family of chips is designed as a differential amplifier and thus has two input pins

(RXp and RXn) on the RFIC. It is necessary to design a network that not only provides a conjugate match to the

input impedance of the LNA but also provides a balanced-to-unbalanced conversion function (i.e., a balun).

The LNA design is differential and thus the RXp and the RXn input pins may be considered interchangeable.

Although the figures in this document may show the matching components connected to the RXp/RXn pins in a

certain fashion, the pin connections may be reversed without change in functionality.

Use of two basic matching network topologies will be considered within this application note.

2.1. Three-Element Match Network

The simplest match network that may be fabricated from discrete components is comprised of three discrete

elements. Two forms of the 3-element match network may be constructed: one with a highpass filter (HPF)

response, and one with a lowpass filter (LPF) response. However, the form with a lowpass filter response is not

realizable at all frequencies and input impedances. As a result, only the form with a highpass filter response is

discussed within this document.

A 3-element (CR1-LR1-CR2) HPF matching network is shown in Figure 1. This matching network has the virtue of

requiring a minimum number of components but results in slightly sub-optimal performance. It is not theoretically

possible to achieve a perfectly balanced single-ended-to-differential conversion function with this matching network

for input impedances with finite values of RLNA. As will be demonstrated, the waveforms obtained at the RXp and

RXn inputs to the RFIC will not be exactly 180° out of phase; the result is a very slight loss in conversion gain in the

LNA and a small drop in overall sensitivity of the RFIC. The reduction in performance is typically less than 0.5 dB;

many customers may view this as an acceptable trade-off for the reduction in the bill of materials (BOM).

The RXp and RXn inputs of the Si446x/Si4362 RX LNA internally contain high value (~15 k) pull-down resistors

to GND. As a result, supplying a DC voltage to these pins is not recommended; use of external AC-coupling to

these pins is suggested. This is inherently supplied by capacitor CR2 of Figure 1.