PCF8575 具有中断输出的远程 16 位 I2C 和 SMBus I/O 扩展器

This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 2.5-V to 5.5-V VCC operation.

The PCF8575 provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface serial clock (SCL) and serial data (SDA).

The device features a 16-bit quasi-bidirectional input/output (I/O) port (P07-P00, P17-P10), 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 (IOH) to VCC is active. An additional strong pullup to VCC (IOHT) 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. 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 input or outputs can be done with the write mode. If a high is applied externally to an I/O that has been written earlier to low, a large current (IOL) will flow to GND.

The PCF8575 provides an open-drain interrupt (INT) output, which 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, the signal 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 (ACK) bit after the rising edge of the SCL signal or in the write mode at the ACK bit after the falling edge of the SCL signal. Interrupts that occur during the ACK 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 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. Thus, the PCF8575 can remain a simple slave device.

Every data transmission to or from the PCF8575 must consist of an even number of bytes. The first data byte in every pair refers to port 0 (P07-P00), and the second data byte in every pair refers to port 1 (P17-P10). To write to the ports (output mode), the master first addresses the slave device, setting the last bit of the byte containing the slave address to logic 0. The PCF8575 acknowledges, and the master sends the first data byte for P07-P00. After the first data byte is acknowledged by the PCF8575, the second data byte (P17-P10) is sent by the master. Once again, the PCF8575 acknowledges the receipt of the data, after which this 16-bit data is presented on the port lines.

The number of data bytes that can be sent successively is not limited. After every two bytes, the previous data is overwritten. When the PCF8575 receives the pairs of data bytes, the first byte is referred to as P07-P00 and the second byte as P17-P10. The third byte is referred to as P07-P00, the fourth byte as P17-P10, and so on.

Before reading from the PCF8575, all ports desired as input should be set to logic 1. To read from the ports (input mode), the master first addresses the slave device, setting the last bit of the byte containing the slave address to logic 1. The data bytes that follow on the SDA are the values on the ports. If the data on the input port changes faster than the master can read, this data may be lost.

When power is applied to VCC, an internal power-on reset holds the PCF8575 in a reset state until VCC has reached VPOR. At that time, the reset condition is released, and the device I2C-bus state machine initializes the bus to its default state.

The hardware pins (A0, A1, and A2) are used to program and vary the fixed I2C address and allow up to eight devices to share the same I2C bus or SMBus. The fixed I2C address of the PCF8575 is the same as the PCF8575C, PCF8574, PCA9535, and PCA9555, allowing up to eight of these devices, in any combination, to share the same I2C bus or SMBus

PCF8575
Voltage Nodes(V) 5.5, 3.6, 2.7, 2.5  
Interrupt Output Yes  
Reset Input No  
fSCLK(Max)(MHz) 0.4  
VCC(Min)(V) 2.5  
VCC(Max)(V) 5.5  
Pin/Package 24SOIC, 24SSOP, 24SSOP/QSOP, 24TSSOP, 24TVSOP, 24VQFN
Operating Temperature Range(°C) -40 to 85  
Max Frequency(kHz) 400  
I2C Address 0100 xxx  
# of I/Os 16  
Vcc range(V) 2.5 to 5.5  
Push–Pull I/O Type Yes
PCF8575 特性
PCF8575 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
PCF8575DBQR ACTIVE -40 to 85 1.45 | 1ku SSOP/QSOP (DBQ) | 24 2500 | LARGE T&R  
PCF8575DBQRE4 ACTIVE -40 to 85 1.45 | 1ku SSOP/QSOP (DBQ) | 24 2500 | LARGE T&R  
PCF8575DBQRG4 ACTIVE -40 to 85 1.45 | 1ku SSOP/QSOP (DBQ) | 24 2500 | LARGE T&R  
PCF8575DBR ACTIVE -40 to 85 1.75 | 1ku SSOP (DB) | 24 2000 | LARGE T&R  
PCF8575DBRE4 ACTIVE -40 to 85 1.75 | 1ku SSOP (DB) | 24 2000 | LARGE T&R  
PCF8575DBRG4 ACTIVE -40 to 85 1.75 | 1ku SSOP (DB) | 24 2000 | LARGE T&R  
PCF8575DGVR ACTIVE -40 to 85 1.45 | 1ku TVSOP (DGV) | 24 2000 | LARGE T&R  
PCF8575DGVRE4 ACTIVE -40 to 85 1.45 | 1ku TVSOP (DGV) | 24 2000 | LARGE T&R  
PCF8575DGVRG4 ACTIVE -40 to 85 1.45 | 1ku TVSOP (DGV) | 24 2000 | LARGE T&R  
PCF8575DW ACTIVE -40 to 85 1.75 | 1ku SOIC (DW) | 24 25 | TUBE  
PCF8575DWG4 ACTIVE -40 to 85 1.75 | 1ku SOIC (DW) | 24 25 | TUBE  
PCF8575DWR ACTIVE -40 to 85 1.45 | 1ku SOIC (DW) | 24 2000 | LARGE T&R  
PCF8575DWRG4 ACTIVE -40 to 85 1.45 | 1ku SOIC (DW) | 24 2000 | LARGE T&R  
PCF8575PW ACTIVE -40 to 85 1.75 | 1ku TSSOP (PW) | 24 60 | TUBE  
PCF8575PWE4 ACTIVE -40 to 85 1.75 | 1ku TSSOP (PW) | 24 60 | TUBE  
PCF8575PWG4 ACTIVE -40 to 85 1.75 | 1ku TSSOP (PW) | 24 60 | TUBE  
PCF8575PWR ACTIVE -40 to 85 1.45 | 1ku TSSOP (PW) | 24 2000 | LARGE T&R  
PCF8575PWRE4 ACTIVE -40 to 85 1.45 | 1ku TSSOP (PW) | 24 2000 | LARGE T&R  
PCF8575PWRG4 ACTIVE -40 to 85 1.45 | 1ku TSSOP (PW) | 24 2000 | LARGE T&R  
PCF8575RGER ACTIVE -40 to 85 1.45 | 1ku VQFN (RGE) | 24 3000 | LARGE T&R  
PCF8575RGERG4 ACTIVE -40 to 85 1.45 | 1ku VQFN (RGE) | 24 3000 | LARGE T&R  
PCF8575 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
PCF8575DBQR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8575DBQR PCF8575DBQR
PCF8575DBQRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8575DBQRE4 PCF8575DBQRE4
PCF8575DBQRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8575DBQRG4 PCF8575DBQRG4
PCF8575DBR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DBR PCF8575DBR
PCF8575DBRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DBRE4 PCF8575DBRE4
PCF8575DBRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DBRG4 PCF8575DBRG4
PCF8575DGVR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DGVR PCF8575DGVR
PCF8575DGVRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DGVRE4 PCF8575DGVRE4
PCF8575DGVRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DGVRG4 PCF8575DGVRG4
PCF8575DW Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DW PCF8575DW
PCF8575DWG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DWG4 PCF8575DWG4
PCF8575DWR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DWR PCF8575DWR
PCF8575DWRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575DWRG4 PCF8575DWRG4
PCF8575PW Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PW PCF8575PW
PCF8575PWE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PWE4 PCF8575PWE4
PCF8575PWG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PWG4 PCF8575PWG4
PCF8575PWR Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PWR PCF8575PWR
PCF8575PWRE4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PWRE4 PCF8575PWRE4
PCF8575PWRG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-1-260C-UNLIM PCF8575PWRG4 PCF8575PWRG4
PCF8575RGER Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8575RGER PCF8575RGER
PCF8575RGERG4 Green (RoHS & no Sb/Br)  CU NIPDAU  Level-2-260C-1 YEAR PCF8575RGERG4 PCF8575RGERG4
PCF8575 应用技术支持与电子电路设计开发资源下载
  1. PCF8575 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)