- 您现在的位置：买卖IC网 > PDF目录378591 > DS2450 1-Wire Quad A/D Converter PDF资料下载
参数资料
| 型号： | DS2450 |
| 英文描述： | 1-Wire Quad A/D Converter |
| 中文描述： | 四路、1-Wire A/D转换器 |
| 文件页数： | 6/24页 |
| 文件大小： | 523K |
| 代理商： | DS2450 |
DS2450
6 of 24
102199
MEMORY MAP PAGE 2, ALARM SETTINGS
Figure 5c
Address
bit 7
bit 6
10
MSBL-A
A
11
MSBH-A
A
12
MSBL-B
B
13
MSBH-B
B
14
MSBL-C
C
15
MSBH-C
C
16
MSBL-D
D
17
MSBH-D
D
bit 5
A
A
B
B
C
C
D
D
bit 4
A
A
B
B
C
C
D
D
bit 3
A
A
B
B
C
C
D
D
bit 2
A
A
B
B
C
C
D
D
bit 1
A
A
B
B
C
C
D
D
bit 0
LSBL-A
LSBH-A
LSBL-B
LSBH-B
LSBL-C
LSBH-C
LSBL-D
LSBH-D
The registers for the alarm threshold voltages of each channel are located in memory page 2 with the low
threshold being at the lower address (Figure 5c). The power-on default thresholds are 00h for low alarm
and FFh for high alarm. The alarm settings are always eight bits. For a resolution higher or equal to
eight bits the alarm flag will be set if the eight most significant bits of the conversion result yield a
number higher than stored in the high alarm register (AFH) or lower than stored in the low alarm register
(AFL). For a resolution lower than eight bits the least significant bits of the alarm registers are ignored.
There is a fourth memory page in the address range of 18 to 1F used during calibration at the factory.
This memory page is accessible to the user through the Read Memory and Write Memory commands.
Changing the data of this page arbitrarily will de-calibrate the A/D converter or make the device
nonfunctional until it undergoes a power-on reset.
If the device is VCC powered the analog circuitry
must be kept permanently active
by writing a value of 40 hex to memory address 1C after power-up.
This also eliminates the offset time otherwise needed with each CONVERT command. See the
description of the CONVERT command for details.
FUNCTION COMMANDS
The Function Command Flow Chart (Figure 6) describes the protocols necessary for accessing the device
registers. Since the memory map of the DS2450 is small compared to the 16-bit addressing capabilities
the 11 most significant bits of the address will be forced to 0 before they enter the CRC-generator. The
communication between master and DS2450 takes place either at regular speed (default, OD = 0) or at
Overdrive Speed (OD = 1). If not explicitly set into Overdrive mode the device assumes regular speed.
READ MEMORY [AAH]
The Read Memory command is used to read conversion results, control/status data and alarm settings.
The bus master follows the command byte with a two byte address (TA1=(T7:T0), TA2=(T15:T8)) that
indicates a starting byte location within the memory map. With every subsequent read data time slot the
bus master receives data from the DS2450 starting at the supplied address and continuing until the end of
an eight-byte page is reached. At that point the bus master will receive a 16-bit CRC of the command
byte, address bytes and data bytes. This CRC is computed by the DS2450 and read back by the bus
master to check if the command word, starting address and data were received correctly. If the CRC read
by the bus master is incorrect, a Reset Pulse must be issued and the entire sequence must be repeated.
Note that the initial pass through the Read Memory flow chart will generate a 16-bit CRC value that is the
result of clearing the CRC-generator and then shifting in the command byte followed by the two address
bytes, and finally the data bytes beginning at the first addressed memory location and continuing through
to the last byte of the addressed page. Subsequent passes through the Read Memory flow chart will
generate a 16-bit CRC that is the result of clearing the CRC-generator and then shifting in the new data
bytes starting at the first byte of the next page.
相关PDF资料 |
PDF描述 |
|---|---|
| DS2450S | 1-Wire Quad A/D Converter |
| DS2480 | Serial 1.Wire Line Driver |
| DS2480S | Serial 1.Wire Line Driver |
| DS2490 | USB to 1-Wire Bridge Chip |
| DS2490S | USB to 1-Wire Bridge Chip |
相关代理商/技术参数 |
参数描述 |
|---|---|
| DS2450S | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| DS2450S/T&R | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| DS2450S+ | 功能描述:模数转换器 - ADC Quad 1-Wire RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| DS2450S+ | 制造商:Maxim Integrated Products 功能描述:SEMICONDUCTOR ((NW)) |
| DS2450S+T&R | 制造商:Maxim Integrated Products 功能描述:IC CONVERTER A/D QUAD 1-W 8-SOIC |
发布紧急采购，3分钟左右您将得到回复。