参数资料
型号: MAX6889ETJ+T
厂商: Maxim Integrated Products
文件页数: 31/40页
文件大小: 0K
描述: IC SEQUENCE/SUPERVISOR 32TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 序列发生器
监视电压数目: 8
输出: 开路漏极,推挽式
复位: 高有效/低有效
复位超时: 可调节/可选择
电压 - 阀值: 8 种可选阀值组合
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 32-WFQFN 裸露焊盘
供应商设备封装: 32-TQFN-EP(5x5)
包装: 带卷 (TR)
EEPROM-Programmable, Octal/Hex/Quad,
Power-Supply Sequencers/Supervisors
master device to generate a clock signal. The master
device (typically a microcontroller) generates SCL and ini-
tiates data transfer on the bus.
A master device communicates to the MAX6889/
MAX6890/MAX6891 by transmitting the proper address
followed by command and/or data words. Each trans-
mit sequence is framed by a START (S) or REPEATED
START (SR) condition and a STOP (P) condition. Each
word transmitted over the bus is 8 bits long and is
always followed by an acknowledge pulse.
SCL is a logic input, while SDA is an open-drain
input/output. SCL and SDA both require external pullup
resistors to generate the logic-high voltage. Use 4.7k ?
resistors for most applications.
Bit Transfer
Each clock pulse transfers one data bit. The data on
SDA must remain stable while SCL is high (Figure 4),
otherwise the MAX6889/MAX6890/MAX6891 register a
START or STOP condition (Figure 5) from the master.
SDA and SCL idle high when the bus is not busy.
Start and Stop Conditions
A master device signals the beginning of a transmission
with a START (S) condition (Figure 5) by transitioning
SDA from high to low while SCL is high. The master
device issues a STOP (P) condition (Figure 5) by transi-
tioning SDA from low to high while SCL is high. A STOP
condition frees the bus for another transmission. The bus
remains active if a REPEATED START condition is gener-
ated, such as in the read byte or block read protocol
(see Figure 8). Both SCL and SDA are high when the bus
is not busy.
SDA
SCL
Early STOP Conditions
The MAX6889/MAX6890/MAX6891 recognize a STOP
condition at any point during transmission except if a
STOP condition occurs in the same high pulse as a
START condition. This condition is not a legal I 2 C for-
mat. At least one clock pulse must separate any START
and STOP condition.
Repeated START Conditions
A REPEATED START (SR) condition may indicate a
change of data direction on the bus. Such a change
occurs when a command word is required to initiate a
read operation (see Figure 8). SR may also be used
when the bus master is writing to several I 2 C devices
and does not want to relinquish control of the bus. The
MAX6889/MAX6890/MAX6891 serial interface supports
continuous write operations with or without an SR condi-
tion separating them. Continuous read operations
require SR conditions because of the change in direction
of data flow.
Acknowledge
The acknowledge bit (ACK) is the 9th bit attached to any
8-bit data word. The receiving device always generates
an ACK. The MAX6889/MAX6890/MAX6891 generate an
ACK when receiving an address or data by pulling SDA
low during the 9th clock period (Figure 6). When trans-
mitting data, such as when the master device reads data
back from the MAX6889/MAX6890/MAX6891, the
MAX6889/MAX6890/MAX6891 wait for the master device
to generate an ACK. Monitoring ACK allows for detection
of unsuccessful data transfers. An unsuccessful data
transfer occurs if the receiving device is busy or if a sys-
tem fault has occurred. In the event of an unsuccessful
SDA
SCL
S
P
DATA LINE STABLE,
DATA VALID
Figure 4. Bit Transfer
CHANGE OF
DATA ALLOWED
START
CONDITION
Figure 5. Start and Stop Conditions
STOP
CONDITION
______________________________________________________________________________________
31
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MAX6889EVCMAXQ 功能描述:监控电路 EEPROM-Programmable Octal/Hex/Quad Power-Supply Sequencers/Supervisors RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟(典型值):10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel
MAX6889EVCMAXQU 功能描述:监控电路 Evaluation Kit/Evaluation System for the MAX6889 RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟(典型值):10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel
MAX6889EVCMODU 功能描述:监控电路 EEPROM-Programmable Octal/Hex/Quad Power-Supply Sequencers/Supervisors RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟(典型值):10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel
MAX6889EVKIT 功能描述:监控电路 Programmers, Development Systems RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟(典型值):10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel
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