{"id":10468,"date":"2026-07-20T04:09:48","date_gmt":"2026-07-20T04:09:48","guid":{"rendered":"https:\/\/ic-vendor.com\/pca9555pw\/"},"modified":"2026-07-20T04:09:48","modified_gmt":"2026-07-20T04:09:48","slug":"pca9555pw","status":"publish","type":"post","link":"https:\/\/ic-vendor.com\/zh\/pca9555pw\/","title":{"rendered":"PCA9555PW"},"content":{"rendered":"

\u4ea7\u54c1\u6982\u89c8<\/h2>\n

The NXP PCA9555PW is a 16-bit I2C-bus\/SMBus GPIO expander with interrupt output in a TSSOP24 package. It provides 16 bits of general purpose parallel I\/O expansion, features 5V tolerant I\/Os, individual I\/O configuration, polarity inversion, and supports up to 400 kHz I2C clock frequency with up to 8 devices on the same bus.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
Supply Voltage (VDD)<\/td>\n2.3 V to 5.5 V<\/td>\n<\/tr>\n
I\/O Bits<\/td>\n16 (two 8-bit ports)<\/td>\n<\/tr>\n
Interface<\/td>\nI2C-bus \/ SMBus<\/td>\n<\/tr>\n
Max Clock Frequency<\/td>\n400 kHz<\/td>\n<\/tr>\n
Max Sink Current per Bit<\/td>\n25 mA<\/td>\n<\/tr>\n
Source Current per Bit<\/td>\n10 mA<\/td>\n<\/tr>\n
Standby Current<\/td>\n0.25 \u00b5A (typical)<\/td>\n<\/tr>\n
Internal Pull-up<\/td>\n100 k\u03a9 per bit<\/td>\n<\/tr>\n
I\/O Tolerance<\/td>\n5V tolerant<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-40\u00b0C to +85\u00b0C<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nTSSOP24 (7.8 x 4.4 x 1.1 mm)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • 16 I\/O pins which default to 16 inputs upon power-up<\/li>\n
  • 5V tolerant I\/Os for mixed-voltage environments<\/li>\n
  • Polarity Inversion register for input flexibility<\/li>\n
  • Active LOW open-drain interrupt output<\/li>\n
  • Internal 100 k\u03a9 pull-up resistors on each I\/O<\/li>\n
  • Noise filter on SCL\/SDA inputs<\/li>\n
  • Three address pins allow up to 8 devices on same bus<\/li>\n
  • Internal power-on reset with no glitch on power-up<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • ACPI power switches in computing systems<\/li>\n
    • Sensor and push-button monitoring<\/li>\n
    • LED control and fan management<\/li>\n
    • Industrial I\/O expansion<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The NXP PCA9555PW is a 16-bit I2C-bus\/SMBus GPIO expander with interrupt output in a TSSOP24 package. It provides 16 bits of general purpose parallel I\/O expansion, features 5V tolerant I\/Os, individual I\/O configuration, polarity inversion, and supports up to 400 kHz I2C clock frequency with up to 8 devices on the same bus. […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,20],"tags":[1774],"chip_brand":[168],"class_list":["post-10468","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-interface-ics","tag-pca9555pw","chip_brand-nxp"],"acf":{"brief_explanation":"16-bit I2C\/SMBus GPIO expander with interrupt, 2.3-5.5V, TSSOP24, 400kHz, 5V tolerant I\/Os","date_code":"","package_case":"TSSOP24 (SOT355-1) 7.8 x 4.4 x 1.1 mm","in_stock":6847,"datasheet":"https:\/\/www.nxp.com\/docs\/en\/data-sheet\/PCA9555.pdf","price":"$0.91 @ 1ku","product_introduction":"The NXP PCA9555PW is a 24-pin CMOS device that provides 16 bits of General Purpose parallel Input\/Output (GPIO) expansion for I2C-bus\/SMBus applications. It was developed to enhance the NXP family of I2C-bus I\/O expanders with improvements including higher drive capability, 5V I\/O tolerance, lower supply current, individual I\/O configuration, and smaller packaging. The device consists of two 8-bit Configuration, Input, Output, and Polarity Inversion registers. The system controller can enable each I\/O as either input or output by writing to the configuration bits. The open-drain interrupt output is activated when any input state differs from its corresponding input port register state. Three hardware address pins allow up to eight devices on the same I2C-bus. The device operates from 2.3V to 5.5V with 0.25 \u00b5A typical standby current.","working_principle":"The PCA9555PW communicates with the host controller via a standard I2C-bus\/SMBus interface at up to 400 kHz. It contains four register pairs (Configuration, Input, Output, Polarity Inversion) for each 8-bit port (Port 0 and Port 1). The Configuration register determines whether each pin is an input (default) or output. The Output register holds data written to pins configured as outputs. The Input register reflects the current state of pins configured as inputs. The Polarity Inversion register allows inverting the polarity of input pins. When any input pin changes state from its registered value, the open-drain interrupt (INT) output is asserted LOW, alerting the host to read the Input registers. Reading the Input register clears the interrupt. Three address pins (A0-A2) set the I2C slave address, allowing up to 8 devices (128 I\/Os) on a single bus.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>\n
      1-4<\/td>A0-A2, P00<\/td>Input\/I\/O<\/td>Address inputs \/ Port 0 pin 0<\/td><\/tr>\n
      5-8<\/td>P01-P04<\/td>I\/O<\/td>Port 0 pins 1-4<\/td><\/tr>\n
      9<\/td>VSS<\/td>Power<\/td>Ground<\/td><\/tr>\n
      10-13<\/td>P05-P07<\/td>I\/O<\/td>Port 0 pins 5-7<\/td><\/tr>\n
      14<\/td>INT<\/td>Output<\/td>Active LOW interrupt output (open-drain)<\/td><\/tr>\n
      15-18<\/td>P10-P13<\/td>I\/O<\/td>Port 1 pins 0-3<\/td><\/tr>\n
      19<\/td>SCL<\/td>Input<\/td>I2C-bus serial clock<\/td><\/tr>\n
      20<\/td>SDA<\/td>I\/O<\/td>I2C-bus serial data<\/td><\/tr>\n
      21-24<\/td>P14-P17<\/td>I\/O<\/td>Port 1 pins 4-7<\/td><\/tr>\n<\/table>","application_scenarios":"
        \n
      • ACPI power switches in computing systems<\/li>\n
      • Sensor monitoring and push-button inputs<\/li>\n
      • LED display control and fan management<\/li>\n
      • Industrial automation I\/O expansion<\/li>\n
      • Embedded system peripheral interface expansion<\/li>\n<\/ul>","alternative_models":"\n
        Manufacturer<\/th>Part Number<\/th>Package<\/th>Notes<\/th><\/tr>\n
        Texas Instruments<\/td>PCA9555PW<\/td>TSSOP-24<\/td>Direct equivalent<\/td><\/tr>\n
        Microchip<\/td>MCP23S17-E\/SS<\/td>SSOP-28<\/td>SPI variant, similar function<\/td><\/tr>\n
        onsemi<\/td>PCA9655E<\/td>TSSOP-24<\/td>Compatible, higher drive current<\/td><\/tr>\n
        NXP<\/td>PCF8575TS<\/td>SSOP-24<\/td>Similar 16-bit I2C expander<\/td><\/tr>\n
        Maxim Integrated<\/td>MAX7317ATG+<\/td>TQFN-24<\/td>10-port I2C expander alternative<\/td><\/tr>\n<\/table>"},"_links":{"self":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/10468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/comments?post=10468"}],"version-history":[{"count":0,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/10468\/revisions"}],"wp:attachment":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/media?parent=10468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/categories?post=10468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/tags?post=10468"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=10468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}