PCF8574 用于 I2C 总线的远程 8 位 I/O 扩展器

This 8-bit input/output (I/O) expander for the two-line bidirectional bus (I2C) is designed for 2.5-V to 6-V VCC operation.

The PCF8574 provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)].

The device features an 8-bit quasi-bidirectional I/O port (P0-P7), including latched outputs with high-current drive capability for directly driving LEDs. Each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal. At power on, the I/Os are high. In this mode, only a current source to VCC is active. An additional strong pullup to VCC allows fast rising edges into heavily loaded outputs. This device turns on when an output is written high and is switched off by the negative edge of SCL. The I/Os should be high before being used as inputs.

The PCF8574 provides an open-drain output (INT) that can be connected to the interrupt input of a microcontroller. An interrupt is generated by any rising or falling edge of the port inputs in the input mode. After time, tiv, INT is valid. Resetting and reactivating the interrupt circuit is achieved when data on the port is changed to the original setting or data is read from, or written to, the port that generated the interrupt. Resetting occurs in the read mode at the acknowledge bit after the rising edge of the SCL signal, or in the write mode at the acknowledge bit after the high-to-low transition of the SCL signal. Interrupts that occur during the acknowledge clock pulse can be lost (or be very short) due to the resetting of the interrupt during this pulse. Each change of the I/Os after resetting is detected and, after the next rising clock edge, is transmitted as INT. Reading from, or writing to, another device does not affect the interrupt circuit.

By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C bus. Therefore, the PCF8574 can remain a simple slave device

PCF8574
Voltage Nodes(V) 5, 3.3  
Interrupt Output Yes  
Reset Input No  
fSCLK(Max)(MHz) 0.1  
VCC(Min)(V) 2.5  
VCC(Max)(V) 6  
Pin/Package 16PDIP, 16QFN, 16SOIC, 20TSSOP, 20TVSOP, 20VQFN  
Operating Temperature Range(°C) -40 to 85  
Max Frequency(kHz) 100  
I2C Address 0100 xxx  
# of I/Os 8  
Vcc range(V) 2.5 to 6.0  
Push–Pull I/O Type Yes
PCF8574 特性
PCF8574 芯片订购指南
器件 状态 温度 价格 封装 | 引脚 封装数量 | 封装载体 丝印标记
PCF8574DGVR ACTIVE -40 to 85 1.00 | 1ku TVSOP (DGV) | 20 2000 | LARGE T&R  
PCF8574DGVRE4 ACTIVE -40 to 85 1.00 | 1ku TVSOP (DGV) | 20 2000 | LARGE T&R  
PCF8574DGVRG4 ACTIVE -40 to 85 1.00 | 1ku TVSOP (DGV) | 20 2000 | LARGE T&R  
PCF8574DW ACTIVE -40 to 85 1.15 | 1ku SOIC (DW) | 16 40 | TUBE  
PCF8574DWE4 ACTIVE -40 to 85 1.15 | 1ku SOIC (DW) | 16 40 | TUBE  
PCF8574DWG4 ACTIVE -40 to 85 1.15 | 1ku SOIC (DW) | 16 40 | TUBE  
PCF8574DWR ACTIVE -40 to 85 1.00 | 1ku SOIC (DW) | 16 2000 | LARGE T&R  
PCF8574DWRE4 ACTIVE -40 to 85 1.00 | 1ku SOIC (DW) | 16 2000 | LARGE T&R  
PCF8574DWRG4 ACTIVE -40 to 85 1.00 | 1ku SOIC (DW) | 16 2000 | LARGE T&R  
PCF8574N ACTIVE -40 to 85 1.00 | 1ku PDIP (N) | 16 25 | TUBE  
PCF8574NE4 ACTIVE -40 to 85 1.00 | 1ku PDIP (N) | 16 25 | TUBE  
PCF8574PW ACTIVE -40 to 85 1.15 | 1ku TSSOP (PW) | 20 70 | TUBE  
PCF8574PWE4 ACTIVE -40 to 85 1.15 | 1ku TSSOP (PW) | 20 70 | TUBE  
PCF8574PWG4 ACTIVE -40 to 85 1.15 | 1ku TSSOP (PW) | 20 70 | TUBE  
PCF8574PWR ACTIVE -40 to 85 1.00 | 1ku TSSOP (PW) | 20 2000 | LARGE T&R  
PCF8574PWRE4 ACTIVE -40 to 85 1.00 | 1ku TSSOP (PW) | 20 2000 | LARGE T&R  
PCF8574PWRG4 ACTIVE -40 to 85 1.00 | 1ku TSSOP (PW) | 20 2000 | LARGE T&R  
PCF8574RGTR ACTIVE -40 to 85 1.00 | 1ku QFN (RGT) | 16 3000 | LARGE T&R  
PCF8574RGTRG4 ACTIVE -40 to 85 1.00 | 1ku QFN (RGT) | 16 3000 | LARGE T&R  
PCF8574RGYR ACTIVE -40 to 85 1.00 | 1ku VQFN (RGY) | 20 3000 | LARGE T&R  
PCF8574RGYRG4 ACTIVE -40 to 85 1.00 | 1ku VQFN (RGY) | 20 3000 | LARGE T&R  
PCF8574 质量与无铅数据
器件 环保计划* 铅/焊球涂层 MSL 等级/回流焊峰 环保信息与无铅 (Pb-free) DPPM / MTBF / FIT 率
PCF8574DGVR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DGVR PCF8574DGVR
PCF8574DGVRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DGVRE4 PCF8574DGVRE4
PCF8574DGVRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DGVRG4 PCF8574DGVRG4
PCF8574DW Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DW PCF8574DW
PCF8574DWE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DWE4 PCF8574DWE4
PCF8574DWG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DWG4 PCF8574DWG4
PCF8574DWR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DWR PCF8574DWR
PCF8574DWRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DWRE4 PCF8574DWRE4
PCF8574DWRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574DWRG4 PCF8574DWRG4
PCF8574N Pb-Free (RoHS)  CU NIPDAU  N/A for Pkg Type PCF8574N PCF8574N
PCF8574NE4 Pb-Free (RoHS)  CU NIPDAU  N/A for Pkg Type PCF8574NE4 PCF8574NE4
PCF8574PW Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PW PCF8574PW
PCF8574PWE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PWE4 PCF8574PWE4
PCF8574PWG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PWG4 PCF8574PWG4
PCF8574PWR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PWR PCF8574PWR
PCF8574PWRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PWRE4 PCF8574PWRE4
PCF8574PWRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574PWRG4 PCF8574PWRG4
PCF8574RGTR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574RGTR PCF8574RGTR
PCF8574RGTRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8574RGTRG4 PCF8574RGTRG4
PCF8574RGYR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8574RGYR PCF8574RGYR
PCF8574RGYRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8574RGYRG4 PCF8574RGYRG4
PCF8574 应用技术支持与电子电路设计开发资源下载
  1. PCF8574 数据资料 dataSheet 下载.PDF
  2. TI 德州仪器I2C 逻辑器件产品选型与价格 . xls
  3. Logic Guide 2009 (PDF 4263 KB)
  4. Shelf-Life Evaluation of Lead-Free Component Finishes (PDF 1305 KB)
  5. Understanding and Interpreting Standard-Logic Data Sheets (PDF 857 KB)
  6. TI IBIS File Creation, Validation, and Distribution Processes (PDF 380 KB)
  7. Implications of Slow or Floating CMOS Inputs (PDF 101 KB)
  8. CMOS Power Consumption and CPD Calculation (PDF 89 KB)
  9. Designing With Logic (PDF 186 KB)
  10. Live Insertion (PDF 150 KB)
  11. Input and Output Characteristics of Digital Integrated Circuits (PDF 1708 KB)
  12. Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc (PDF 43 KB)
  13. HiRel Unitrode Power Management Brochure (PDF 206 KB)
  14. LOGIC Pocket Data Book (PDF 6001 KB)
  15. HiRel Unitrode Power Management Brochure (PDF 206 KB)
  16. Logic Cross-Reference (PDF 2938 KB)