Datasheet > PCA8574N,112

PCA8574N,112

更新时间： 2023-02-26 15:35:12

品牌	Logo	应用领域
恩智浦 - NXP		PC
页数	文件大小	规格书
27页	160K
描述
PCA8574/74A - Remote 8-bit I/O expander for I²C-bus with interrupt DIP 16-Pin

阅读下载

获取价格

数据手册

如果您发现信息不准确，欢迎纠错

PCA8574N,112 数据手册

PCA8574/74A

NXP Semiconductors

Remote 8-bit I/O expander for I²C-bus with interrupt

Table 5.

PCA8574A address map

Address

38h

39h

3Ah

3Bh

3Ch

3Dh

3Eh

3Fh

8. I/O programming

8.1 Quasi-bidirectional I/O architecture

The PCA8574/74A’s 8 ports (see Figure 2) are entirely independent and can be used

either as input or output ports. Input data is transferred from the ports to the

microcontroller in the Read mode (see Figure 9). Output data is transmitted to the ports in

the Write mode (see Figure 8).

This quasi-bidirectional I/O can be used as an input or output without the use of a control

signal for data directions. At power-on the I/Os are HIGH. In this mode only a current

source (I_OH) to V_DDis active. An additional strong pull-up to V_DD(I_trt(pu)) allows fast rising

edges into heavily loaded outputs. These devices turn on when an output is written HIGH,

and are switched off by the negative edge of SCL. The I/Os should be HIGH before being

used as inputs. After power-on, as all the I/Os are set HIGH, all of them can be used as

inputs. Any change in setting of the I/Os as either inputs or outputs can be done with the

write mode.

Remark: If a HIGH is applied to an I/O which has been written earlier to LOW, a large

current (I_OL) will ﬂow to V_SS

8.2 Writing to the port (Output mode)

To write, the master (microcontroller) ﬁrst addresses the slave device. By setting the last

bit of the byte containing the slave address to logic 0 the write mode is entered. The

PCA8574/74A acknowledges and the master sends the data byte for P7 to P0 and is

acknowledged by the PCA8574/74A. The 8-bit data is presented on the port lines after it

has been acknowledged by the PCA8574/74A.

The number of data bytes that can be sent successively is not limited. The previous data

is overwritten every time a data byte has been sent.

PCA8574_PCA8574A_2

Product data sheet

Rev. 02 — 14 May 2007

7 of 27

1...4 5 678 9 10...27

下载PDF

与PCA8574N,112相关器件

型号	品牌	描述	获取价格	数据表
PCA8574PW	NXP	Remote 8-bit I/O expander for I2C-bus with interrupt	获取价格
PCA8574PW,112	NXP	PCA8574/74A - Remote 8-bit I/O expander for I	获取价格
PCA8574TS	NXP	Remote 8-bit I/O expander for I2C-bus with interrupt	获取价格
PCA8574TS,118	NXP	PCA8574/74A - Remote 8-bit I/O expander for I	获取价格
PCA8575	NXP	Remote 16-bit I/O expander for I2C-bus with interrupt	获取价格
PCA8575BQ	NXP	Remote 16-bit I/O expander for I2C-bus with interrupt	获取价格