参数资料
型号: MAX7322AEE+
厂商: Maxim Integrated Products
文件页数: 18/18页
文件大小: 0K
描述: IC I/O EXPANDER I2C 4B 16QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 100
接口: I²C
输入/输出数: 4
中断输出:
频率 - 时钟: 400kHz
电源电压: 1.7 V ~ 5.5 V
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
供应商设备封装: 16-QSOP
包装: 管件
包括: POR
MAX7322
I2C Port Expander with
4 Push-Pull Outputs and 4 Inputs
_______________________________________________________________________________________
9
“snapshot” register for transition monitoring. The snap-
shot is continuously compared with the actual input
conditions, and if a change is detected for any port
input, then an internal transition flag is set for that port,
and INT is asserted to signal a state change. The four
port inputs are sampled (internally latched into the
snapshot register) and the old transition flags cleared
during the I2C acknowledge of every MAX7322 read
and write access. The previous port transition flags are
read through the serial interface as the second byte of
a 2-byte read sequence.
A long read sequence (more than 2 bytes) can be used
to poll the expander continuously without the overhead
of resending the slave address. If more than 2 bytes
are read from the expander, the expander repeatedly
returns the input port data alternating with the transition
flags. The inputs are repeatedly resampled and the
transition flags repeatedly reset for each pair of bytes
read. All changes that occur during a long read
sequence are detected and reported.
The MAX7322 includes a 4-bit interrupt mask register
that selects which inputs generate an interrupt upon
change. Each input’s transition flag is set when its input
changes, independent of the interrupt mask register
settings. The interrupt mask register allows the proces-
sor to be interrupted for critical events, while the inputs
and the transition flags can be polled periodically to
detect less-critical events.
The INT output is not reasserted during a read sequence
to avoid recursive reentry into an interrupt service rou-
tine. Instead, if a data change occurs that would normal-
ly cause the INT output to be set, the INT assertion is
delayed until the STOP condition. INT is not reasserted
upon a STOP condition if the changed input data is
read before the STOP occurs. The INT logic ensures
that unnecessary interrupts are not asserted, yet data
changes are detected and reported no matter when the
change occurs.
Transition Detection Masks
The transition detection logic incorporates a change
flag and an interrupt mask bit for each of the four input
ports. The four change flags can be read through the
serial interface, and the 4-bit interrupt mask is set
through the serial interface.
Each port’s change flag is set when that port’s input
changes, and the change flag remains set even if the
input returns to its original state. The port’s interrupt
mask determines whether a change on that input port
generates an interrupt. Enable interrupts for high-priori-
ty inputs using the interrupt mask. The interrupt allows
the system to respond quickly to changes on these
inputs. Poll the MAX7322 periodically to monitor less-
important inputs. The change flags indicate whether a
permanent or transient change has occurred on any
input since the MAX7322 was last accessed.
Port Outputs
Write one byte to the MAX7322 to set the output port
levels for the four push-pull outputs, and the interrupt
mask for the four inputs simultaneously.
Serial Interface
Serial Addressing
The MAX7322 operates as a slave that sends and
receives data through an I2C interface. The interface
uses a serial-data line (SDA) and a serial-clock line (SCL)
to achieve bidirectional communication between mas-
ter(s) and slave(s). The master initiates all data transfers
to and from the MAX7322 and generates the SCL clock
that synchronizes the data transfer (Figure 1).
SCL
SDA
tR
tF
tBUF
START
CONDITION
STOP
CONDITION
REPEATED START CONDITION
START CONDITION
tSU,STO
tHD,STA
tSU,STA
tHD,DAT
tSU,DAT
tLOW
tHIGH
tHD,STA
Figure 1. 2-Wire Serial Interface Timing Details
相关PDF资料
PDF描述
MAX7310AUE+ IC I/O EXPANDER I2C 8B 16TSSOP
MAX7317ATE+ IC I/O EXPANDER SPI 10B 16TQFN
MAX7317AEE+ IC I/O EXPANDER SPI 10B 16QSOP
MAX7315ATE+ IC I/O EXPANDER I2C 8B 16TQFN-EP
MAX7321ATE+ IC I/O EXPANDER I2C 8B 16TQFN-EP
相关代理商/技术参数
参数描述
MAX7322AEE+ 功能描述:接口-I/O扩展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 逻辑系列: 输入/输出端数量: 最大工作频率:100 kHz 工作电源电压:1.65 V to 5.5 V 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:HVQFN-16 封装:Reel
MAX7322AEE+T 功能描述:接口-I/O扩展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 逻辑系列: 输入/输出端数量: 最大工作频率:100 kHz 工作电源电压:1.65 V to 5.5 V 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:HVQFN-16 封装:Reel
MAX7322AEE-T 功能描述:接口-I/O扩展器 RoHS:否 制造商:NXP Semiconductors 逻辑系列: 输入/输出端数量: 最大工作频率:100 kHz 工作电源电压:1.65 V to 5.5 V 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:HVQFN-16 封装:Reel
MAX7322ATE 功能描述:接口-I/O扩展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 逻辑系列: 输入/输出端数量: 最大工作频率:100 kHz 工作电源电压:1.65 V to 5.5 V 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:HVQFN-16 封装:Reel
MAX7322ATE+ 功能描述:接口-I/O扩展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 逻辑系列: 输入/输出端数量: 最大工作频率:100 kHz 工作电源电压:1.65 V to 5.5 V 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:HVQFN-16 封装:Reel