Data Sheet
用于 I2C 总线的 PCF8574A 远程 8 位 I/O 扩展器
本资源的原文使用英文撰写。 为方便起见，TI 提供了译文；由于翻译过程中可能使用了自动化工具，TI 不保证译文的准确性。 为确认准确性，请务必访问 ti.com 参考最新的英文版本（控制文档）。
1 特性
- 低待机流耗，最大值为 10μA
- I2C 至并行端口扩展器
- 开漏中断输出
- 兼容大多数微控制器
- 具有高电流驱动能力的锁存输出，用于直接驱动 LED
- 闩锁性能超过 100mA，符合 JESD 78 II 类规范的要求
3 说明
这款面向两线制双向总线 (I2C) 的 8 位输入/输出 (I/O) 扩展器设计为在 2.5V 至 6V VCC 下运行。
PCF8574A 器件通过 I2C 接口 [串行时钟 (SCL)、串行数据 (SDA)] 为大多数微控制器系列提供通用远程 I/O 扩展。
该器件具有一个 8 位准双向 I/O 端口 (P0–P7)，其中包括具有高电流驱动能力的锁存输出，用于直接驱动 LED。每个准双向 I/O 都可以用作输入或输出（无需使用数据方向控制信号）。在上电时，这些 I/O 处于高电平。在该模式下，仅有一个连接到 VCC 的电流源处于活动状态。
器件信息
| 器件型号 | 封装(1) | 本体尺寸（标称值） |
|---|---|---|
| PCF8574A | VQFN (20) | 4.50mm × 3.50mm |
| PDIP (16) | 19.30mm × 6.35mm | |
| SOIC (16) | 10.30mm × 7.50mm | |
| TSSOP (20) | 6.50mm × 4.40mm | |
| TVSOP (20) | 5.00mm × 4.40mm |
(1) 如需了解所有可用封装，请参阅数据表末尾的可订购产品附录。
4 Pin Configuration and Functions
Figure 4-1 DW or N Package16 PinsTop
View
Figure 4-2 RGY Package20 PinsTop View
Figure 4-3 DGV or PW Package20 PinsTop ViewTable 4-1 Pin Functions
| PIN | TYPE | DESCRIPTION | |||
|---|---|---|---|---|---|
| NAME | RGY | DGV or PW | DW or N | ||
| A[0..2] | 6, 7, 9 | 6, 7, 9 | 1, 2, 3 | I | Address inputs 0 through 2. Connect directly to VCC or ground. Pullup resistors are not needed. |
| GND | 15 | 15 | 8 | — | Ground |
| INT | 1 | 1 | 13 | O | Interrupt output. Connect to VCC through a pullup resistor. |
| NC | 3, 8, 13, 18 | 3, 8, 13, 18 | - | — | Do not connect |
| P[0..7] | 10, 11, 12, 14, 16, 17, 19, 20 | 10, 11, 12, 14, 16, 17, 19, 20 | 4, 5, 6, 7, 9, 10, 11, 12 | I/O | P-port input/output. Push-pull design structure. |
| SCL | 2 | 2 | 14 | I | Serial clock line. Connect to VCC through a pullup resistor |
| SDA | 4 | 4 | 15 | I/O | Serial data line. Connect to VCC through a pullup resistor. |
| VCC | 5 | 5 | 16 | — | Voltage supply |
5 Specifications
5.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
| MIN | MAX | UNIT | |||
|---|---|---|---|---|---|
| VCC | Supply voltage range | –0.5 | 6.5 | V | |
| VI | Input voltage range(2) | –0.5 | VCC + 0.5 | V | |
| VO | Output voltage range(2) | –0.5 | VCC + 0.5 | V | |
| IIK | Input clamp current | VI < 0 | –20 | mA | |
| IOK | Output clamp current | VO < 0 | –20 | mA | |
| IOK | Input/output clamp current | VO < 0 or VO > VCC | ±400 | μA | |
| IOL | Continuous output low current | VO = 0 to VCC | 50 | mA | |
| IOH | Continuous output high current | VO = 0 to VCC | –4 | mA | |
| Continuous current through VCC or GND | ±100 | mA | |||
| TJ | Junction temperature | 150 | °C | ||
| Tstg | Storage temperature range | –65 | 150 | °C | |
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Section 5.3 is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) The input negative-voltage and output voltage ratings may be exceeded if the input and output current ratings are observed.
5.2 ESD Ratings
| VALUE | UNIT | |||
|---|---|---|---|---|
| V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins (1) | 1000 | V |
| Charged-device model (CDM), per JEDEC specification JESD22-C101, all pins (2) | 1500 | |||
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
5.3 Recommended Operating Conditions
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| VCC | Supply voltage | 2.5 | 6 | V |
| VIH | High-level input voltage | 0.7 × VCC | VCC + 0.5 | V |
| VIL | Low-level input voltage | –0.5 | 0.3 × VCC | V |
| IOH | High-level output current | –1 | mA | |
| IOL | Low-level output current | 25 | mA | |
| TA | Operating free-air temperature | –40 | 85 | °C |
