DS18B20-PAR
15 of 19
the read time slot. Therefore, the master must release the bus and then sample the bus state within 15 約
from the start of the slot.
Figure 14 illustrates that the sum of T
INIT
, T
RC
, and T
SAMPLE
must be less than 15 ?/SPAN>s for a read time slot.
Figure 15 shows that system timing margin is maximized by keeping T
INIT
and T
RC
as short as possible
and by locating the master sample time during read time slots towards the end of the 15 約 period.
DETAILED MASTER READ 1 TIMING Figure 14
RECOMMENDED MASTER READ 1 TIMING Figure 15
DS18B20-PAR OPERATION EXAMPLE 1
In this example there are multiple DS18B20-PARs on the bus. The bus master initiates a temperature
conversion in a specific DS18B20-PAR and then reads its scratchpad and recalculates the CRC to verify
the data.
MASTER MODE
DATA (LSB FIRST)
COMMENTS
TX
Reset
Master issues reset pulse.
RX
Presence
DS18B20-PARs respond with presence pulse.
TX
55h
Master issues Match ROM command.
TX
64-bit ROM code
Master sends DS18B20-PAR ROM code.
TX
44h
Master issues Convert T command.
TX
DQ line held high by
strong pullup
Master applies strong pullup to DQ for the duration of the
conversion (t
conv
).
TX
Reset
Master issues reset pulse.
RX
Presence
DS18B20-PARs respond with presence pulse.
TX
55h
Master issues Match ROM command.
TX
64-bit ROM code
Master sends DS18B20-PAR ROM code.
TX
BEh
Master issues Read Scratchpad command.
V
PU
GND
1-WIRE BUS
15 s
VIH of Master
T
RC
T
INT
> 1 ?/SPAN>s
Master samples
LINE TYPE LEGEND
Bus master pulling low
Resistor pullup
V
PU
GND
1-WIRE BUS
15 s
VIH of Master
T
RC
=
small
T
INT
=
small
Master samples
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
DS18B20Z/T&R
IC THERM MICROLAN PROG-RES 8SOIC
DS2740U+T&R
IC CURRENT GAUGE(15BIT) 8UMAX
DS28EA00U+T&R
IC THERMOMETER 1-WIRE 8-USOP
DS3920T-001+
IC CURRENT MIRROR 5:1 SOT23-6
DS4560LS-LO+T
IC SWITCH HOT-PLUG 12V 8-SOIC
DS600U+T&R
IC SENSOR TEMP 8-USOP
DS620U+
IC THERMOMETER/STAT DIG 8MSOP
DS7505U+T&R
IC DGTL THERMOMETER 2WIRE 8-USOP
相关代理商/技术参数
DS18B20+T&R
制造商:Maxim Integrated Products 功能描述: 制造商:Maxim Integrated Products 功能描述:PROGRAMMABLE THERMOMETER 制造商:Maxim Integrated Products 功能描述:TEMP SENSOR DGTL SERL (1-WIRE) 3PIN TO-92 - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC THERM MICROLAN PROG-RES TO-92 制造商:Maxim Integrated Products 功能描述:IC THERM MICROLAN PROG-RES TO92 制造商:Maxim Integrated Products 功能描述:Board Mount Temperature Sensors Prgmble Resolution 1-Wire Parasite Pwr
DS18B20+T&R
功能描述:板上安装温度传感器 Prgmble Resolution 1-Wire Parasite Pwr RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS18B20-PAR
功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS18B20-PAR/T&R
功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS18B20-PAR_07
制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:1-Wire Parasite-Power Digital Thermometer
DS18B20-PAR+T&R
制造商:Maxim Integrated Products 功能描述: 制造商:Maxim Integrated Products 功能描述:TEMP SENSOR DGTL 1-WIRE 3PIN TO-92 - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC THERM MICROLAN PROG-RES TO-92 制造商:Maxim Integrated Products 功能描述:Board Mount Temperature Sensors Prgmble Resolution 1-Wire Parasite Pwr
DS18B20-PAR+T&R
功能描述:板上安装温度传感器 Prgmble Resolution 1-Wire Parasite Pwr RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS18B20-SL
制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:Programmable Resolution 1-Wire Digital Thermometer