欢迎访问ic37.com |
会员登录 免费注册
发布采购

71M6543H 参数 Datasheet PDF下载

71M6543H图片预览
型号: 71M6543H
PDF下载: 下载PDF文件 查看货源
内容描述: 可选增益1或8的一个电流电能表计量芯片的补偿 [Selectable Gain of 1 or 8 for One Current Energy Meter ICs Metrology Compensation]
分类和应用:
文件页数/大小: 157 页 / 2164 K
品牌: MAXIM [ MAXIM INTEGRATED PRODUCTS ]
 浏览型号71M6543H的Datasheet PDF文件第18页浏览型号71M6543H的Datasheet PDF文件第19页浏览型号71M6543H的Datasheet PDF文件第20页浏览型号71M6543H的Datasheet PDF文件第21页浏览型号71M6543H的Datasheet PDF文件第23页浏览型号71M6543H的Datasheet PDF文件第24页浏览型号71M6543H的Datasheet PDF文件第25页浏览型号71M6543H的Datasheet PDF文件第26页  
71M6543F/H Data Sheet  
8
2.2.8 71M6xx3 Isolated Sensor Interface  
2.2.8.1 General Description  
Non-isolating sensors, such as shunt resistors, can be connected to the inputs of the 71M6543 via a  
combination of a pulse transformer and a 71M6xx3 IC (a top-level block diagram of this sensor interface  
is shown in Figure 31). The 71M6xx3 receives power directly from the 71M6543 via a pulse transformer  
and does not require a dedicated power supply circuit. The 71M6xx3 establishes 2-way communication  
with the 71M6543, supplying current samples and auxiliary information such as sensor temperature via a  
serial data stream.  
Up to three 71M6xx3 Isolated Sensors can be supported by the 71M6543. When a remote sensor  
interface is enabled, the two analog current inputs become re-configured as a digital remote sensor  
interface. For example, when control bit RMT2_E = 1, the IADC2-IADC3 analog pins are re-configured as  
the digital interface pins to the remote sensor.  
Each 71M6xx3 Isolated Sensor consists of the following building blocks:  
Power supply that derives power from pulses received from the 71M6543  
Bi-directional digital communications interface  
Shunt signal pre-amplifier  
22-bit 2nd Order Sigma-Delta ADC Converter with precision bandgap reference (chopping amplifier)  
Temperature sensor (for digitally compensating VREF)  
Fuse system containing part-specific information  
During an ordinary multiplexer cycle, the 71M6543 internally determines which other channels are  
enabled with MUX_DIV[3:0] (I/O RAM 0x2100[7:4]). At the same time, it decimates the modulator output  
from the 71M6xx3 Isolated Sensors. Each result is written to CE RAM during one of its CE access time  
slots.  
2.2.8.2 Communication between 71M6543 and 71M6xx3 Isolated Sensor  
The ADC of the 71M6xx3 derives its timing from the power pulses generated by the 71M6543 and as a  
result, operates its ADC slaved to the frequency of the power pulses. The generation of power pulses, as well  
as the communication protocol between the 71M6543 and 71M6xx3 Isolated Sensor, is automatic and  
transparent to the user. Details are not covered in this data sheet.  
2.2.8.3 Control of the 71M6xx3 Isolated Sensor  
The 71M6543 can read or write certain types of information from each 71M6xx3 remote sensor.  
The data to be read is selected by a combination of the RCMD[4:0] and TMUXRn[2:0]. To perform a read  
transaction from one of the 71M6xx3 devices, the MPU first writes the TMUXRn[2:0] field (where n = 2, 4, 6,  
located at I/O RAM 0x270A[2:0], 0x270A[6:4] and 0x2709[2:0], respectively). Next, the MPU writes  
RCMD[4:0] (SFR 0xFC[4:0]) with the desired command and phase selection. When the RCMD[4:2] bits  
have cleared to zero, the transaction has been completed and the requested data is available in  
RMT_RD[15:0] (I/O RAM 0x2602[7:0] is the MSB and 0x2603[7:0] is the LSB). The read parity error bit,  
PERR_RD (SFR 0xFC[6]) is also updated during the transaction. If the MPU writes to RCMD[4:0] before a  
previously initiated read transaction is completed, the command is ignored. Therefore, the MPU must wait  
for RCMD[4:2]=0 before proceeding to issue the next remote sensor read command.  
If the CE is running (CE_E=1), the MPU must write RCMD[4:0] immediately after a CE_BUSY rising  
edge. RCMD[4:0] must be written before the next rising edge of MUX_SYNC. Failure to do this can cause  
incorrect data to be read.  
The RCMD[4:0] field is divided into two sub-fields, COMMAND=RCMD[4:2] and PHASE=RCMD[1:0], as  
shown in Table 4.  
.
22  
© 2008-2010 MAXIM/TERIDIAN Semiconductor Corporation  
v1.2