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参数资料
| 型号： | LTC1865AIMS |
| 元件分类： | ADC |
| 英文描述： | Analog to Digital Converter |
| 中文描述： | 模数转换器 |
| 文件页数： | 8/20页 |
| 文件大小： | 278K |
| 代理商： | LTC1865AIMS |
16
LTC1864/LTC1865
18645f
APPLICATIO S I FOR ATIO
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Transmit LTC1864 Data Over Modular Telephone Wire
Using Simple Transmitter/Receiver
Figure 6 shows a simple Manchester encoder and differ-
ential transmitter suitable for use with the LTC1864. This
circuit allows transmission of data over inexpensive tele-
phone wire. This is useful for measuring a remote sensor,
particularly when the cost of preserving the analog signal
over a long distance is high.
Manchester encoding is a clock signal that is modulated
by exclusive ORing with the data signal. The resulting
signal contains both clock and data information and has an
average duty cycle of 50%, that also allows transformer
coupling. In practice, generating a Manchester encoded
signal with an XOR gate will often produce glitches due to
the skew between data and clock transitions. The D flip-
flops in this encoder retime the clock and data such that
the respective edges are closely aligned, effectively sup-
pressing glitches. The retimed data and clock are then
XORed to produce the Manchester encoded data, which is
interfaced to telephone wire with an LTC1485 RS485
transceiver.
In order to synchronize to incoming data, the receiver
needs a sequence to indicate the start of a data word. The
transmitter schematic shows logic that will produce 31
zeros, a start bit, followed by the 16 data bits (one sample
every 48 clock cycles) at a clock frequency of 1MHz set by
the LTC1799 oscillator. Sending at least 18 zeros before
each start bit ensures that if synchronization is lost, the
receiver can resynchronize to a start bit under all condi-
tions. The serial to parallel converter shown in Figure 7
requires 18 zeros to avoid triggering on data bits.
The Manchester receiver shown in Figure 7 was adopted
from Xilinx application note 17-30 and would typically be
implemented in an FPGA. The decoder clock frequency is
nominally 8 times the transmit clock frequency and is very
tolerant of frequency errors. The outputs of the decoder
are data and a strobe that indicates a valid data bit. The data
can be deserialized using shift registers as shown. The
start bit resets the J-K/flip-flop on its way into the first shift
register. When it appears at the QHIN output of the second
shift register, it sets the flip-flop that loads the parallel data
into the output register.
With AC family CMOS logic at 5V the receiver clock
frequency is limited to 20MHz; the corresponding trans-
mitter clock frequency is 2.5MHz. If the receiver is imple-
mented in an FPGA that can be clocked at 160MHz, the
LTC1864 can be clocked at its rated clock frequency of
20MHz.
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| LTC1865AIMS#PBF | 功能描述:IC A/D CONV 2CH 16BIT 10-MSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1 系列:microPOWER™ 位数:8 采样率（每秒）:1M 数据接口:串行，SPI? 转换器数目:1 功率耗散（最大）:- 电压电源:模拟和数字 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:24-VFQFN 裸露焊盘 供应商设备封装:24-VQFN 裸露焊盘（4x4） 包装:Digi-Reel® 输入数目和类型:8 个单端，单极 产品目录页面:892 (CN2011-ZH PDF) 其它名称:296-25851-6 |
| LTC1865AIMS#TR | 功能描述:IC A/D CONV 2CH 16BIT 10-MSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:12 采样率（每秒）:300k 数据接口:并联 转换器数目:1 功率耗散（最大）:75mW 电压电源:单电源 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC（0.295"，7.50mm 宽） 供应商设备封装:24-SOIC 包装:带卷 (TR) 输入数目和类型:1 个单端，单极；1 个单端，双极 |
| LTC1865AIMS#TRPBF | 功能描述:IC A/D CONV 2CH 16BIT 10-MSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:12 采样率（每秒）:300k 数据接口:并联 转换器数目:1 功率耗散（最大）:75mW 电压电源:单电源 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC（0.295"，7.50mm 宽） 供应商设备封装:24-SOIC 包装:带卷 (TR) 输入数目和类型:1 个单端，单极；1 个单端，双极 |
| LTC1865AIS8 | 功能描述:IC A/D CONV 2CH 16BIT 8-SOIC RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:16 采样率（每秒）:45k 数据接口:串行 转换器数目:2 功率耗散（最大）:315mW 电压电源:模拟和数字 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SOIC（0.295"，7.50mm 宽） 供应商设备封装:28-SOIC W 包装:带卷 (TR) 输入数目和类型:2 个单端，单极 |
| LTC1865AIS8#PBF | 功能描述:IC A/D CONV 2CH 16BIT 8-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:16 采样率（每秒）:45k 数据接口:串行 转换器数目:2 功率耗散（最大）:315mW 电压电源:模拟和数字 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SOIC（0.295"，7.50mm 宽） 供应商设备封装:28-SOIC W 包装:带卷 (TR) 输入数目和类型:2 个单端，单极 |
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