DS2430A
1-WIRE BUS SYSTEM
The 1-Wire bus is a system that has a single bus master and one or more slaves. In all instances, the
DS2430A is a slave device. The bus master is typically a microcontroller. The discussion of this bus
system is broken down into three topics: hardware configuration, transaction sequence, and 1-Wire
signaling (signal type and timing). The 1-Wire protocol defines bus transactions in terms of the bus state
during specified time slots that are initiated on the falling edge of sync pulses from the bus master.
Hardware Configuration
The 1-Wire bus has only a single line by definition; it is important that each device on the bus be able to
drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must have open
drain connection or three-state outputs. The 1-Wire port of the DS2430A is open drain with an internal
circuit equivalent to that shown in Figure 7. A multidrop bus consists of a 1-Wire bus with multiple
slaves attached. The DS2430A communicates at regular 1-Wire speed, 15.3kbits per second, and requires
a pullup resistor as shown in Figure 7. The idle state for the 1-Wire bus is high. If for any reason a
transaction needs to be suspended, the bus MUST be left in the idle state if the transaction is to resume. If
this does not occur and the bus is left low for more than 120μs, one or more of the devices on the bus may
be reset.
HARDWARE CONFIGURATION Figure 7
R PU
I L
R PU
Note: Depending on the 1-Wire communication speed and the bus characteristics, the optimal pullup
resistor value will be in the 0.3k ? to 2.2k ? range. To write to a single device, a R PUPmax resistor and
V PUP of at least 4.0V is sufficient. For writing multiple DS2430As simultaneously or operation at low
V PUP , the resistor should be bypassed by a low-impedance pullup to V PUP while the device copies the
scratchpad to EEPROM.
9 of 19
相关PDF资料
DS2431GA+U IC EEPROM 1024BIT 2SFN
DS2433X-S#T IC EEPROM 4KBIT 6FCHIP
DS2433X-Z01 IC EEPROM 4KBIT 6FCHIP
DS24B33G+T&R IC EEPROM 4KBIT 2SFN
DS2502-E64+ IC OTP 1KBIT TO92-3
DS2502P-E48+T&R IC OTP 1KBIT 6TSOC
DS2502S+ IC OTP 1KBIT 8SOIC
DS2505+T&R IC OTP 16KBIT TO92-3
相关代理商/技术参数
DS2430AP+TR 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:256-Bit 1-Wire EEPROM
DS2430AT 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:256-Bit 1-Wire EEPROM
DS2430AV 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:256-Bit 1-Wire EEPROM
DS2430AX 功能描述:电可擦除可编程只读存储器 RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
DS2430AX#T&R 功能描述:电可擦除可编程只读存储器 RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
DS2430AX#U 功能描述:电可擦除可编程只读存储器 RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
DS2430AX-S 功能描述:电可擦除可编程只读存储器 RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
DS2430AX-S#T&R 制造商:Maxim Integrated Products 功能描述: