{"id":8031,"date":"2026-06-28T08:47:51","date_gmt":"2026-06-28T08:47:51","guid":{"rendered":"https:\/\/ic-vendor.com\/pca9539bs-2\/"},"modified":"2026-06-28T11:43:38","modified_gmt":"2026-06-28T11:43:38","slug":"pca9539bs-2","status":"publish","type":"post","link":"https:\/\/ic-vendor.com\/zh\/pca9539bs-2\/","title":{"rendered":"PCA9539BS"},"content":{"rendered":"<h2>PCA9539BS Overview<\/h2>\n<p>The PCA9539BS is a 16-bit I2C-bus low-power I\/O expander from NXP with integrated interrupt output and reset input, supply voltage 2.3V-5.5V, in a TSSOP-24 package, ideal for GPIO expansion needs.<\/p>\n<h3>\u4e3b\u8981\u529f\u80fd<\/h3>\n<ul>\n<li>16-bit I\/O port<\/li>\n<li>I2C interface (400kHz)<\/li>\n<li>Supply voltage: 2.3V-5.5V<\/li>\n<li>Interrupt output<\/li>\n<li>Reset input<\/li>\n<li>Standby current: 1uA<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>PCA9539BS Overview The PCA9539BS is a 16-bit I2C-bus low-power I\/O expander from NXP with integrated interrupt output and reset input, supply voltage 2.3V-5.5V, in a TSSOP-24 package, ideal for GPIO expansion needs. Key Features 16-bit I\/O port I2C interface (400kHz) Supply voltage: 2.3V-5.5V Interrupt output Reset input Standby current: 1uA<\/p>","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":[],"chip_brand":[168],"class_list":["post-8031","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-interface-ics","chip_brand-nxp"],"acf":{"brief_explanation":"16-bit I2C I\/O expander, TSSOP-24","date_code":"","package_case":"TSSOP-24 (7.80 x 4.40 x 1.20 mm)","in_stock":9620,"datasheet":"https:\/\/www.nxp.com\/docs\/en\/data-sheet\/PCA9539_PCA9539R.pdf","price":"$1.10 @ 1ku","product_introduction":"The PCA9539BS is a 16-bit I2C-bus and SMBus-compatible I\/O expander from NXP Semiconductors in a 24-pin HVQFN (4 x 4 x 0.85 mm) package. It provides 16 quasi-bidirectional I\/O pins that can be individually configured as inputs or outputs. The device features an active-low interrupt output (INT) that asserts on any input state change, a polarity inversion register, low standby current of 0.25 uA, and 400 kHz I2C clock rate. Operating from 2.3 V to 5.5 V over the -40 C to +85 C temperature range, it supports up to four devices on one I2C bus via two address pins.","working_principle":"The PCA9539BS expands the I\/O capability of a microcontroller through the I2C serial bus. The device appears as a set of I2C-register-mapped ports: Input Port registers read the current state of all 16 I\/O pins, Output Port registers set the output latch value, Polarity Inversion registers can invert the input data, and Configuration registers control each pin direction (input or output). When configured as outputs, writing a 0 strongly drives the pin low while writing a 1 allows the internal weak pull-up to pull the pin high. When configured as inputs, the output latch should be set to 1, and the pin state can be read from the Input Port register. The interrupt output (INT) is asserted active-low whenever any input pin changes state from its previously read value, eliminating the need for the host to continuously poll the device. The two hardware address pins (A0, A1) allow up to 4 PCA9539 devices to share the same I2C bus, providing up to 64 additional I\/O pins. The RESET pin resets all registers to default values without cycling power, useful for system initialization.","pin_description":"<table><tr><th>Pin<\/th><th>Name<\/th><th>Description<\/th><\/tr><tr><td>1<\/td><td>A0<\/td><td>I2C address bit 0; connect to VDD or GND<\/td><\/tr><tr><td>2<\/td><td>A1<\/td><td>I2C address bit 1; connect to VDD or GND<\/td><\/tr><tr><td>3<\/td><td>RESET<\/td><td>Active-low reset; resets all registers to default<\/td><\/tr><tr><td>4-7<\/td><td>IO0.0-IO0.3<\/td><td>Port 0 I\/O pins 0-3; quasi-bidirectional<\/td><\/tr><tr><td>8<\/td><td>VSS<\/td><td>Ground<\/td><\/tr><tr><td>9-12<\/td><td>IO0.4-IO0.7<\/td><td>Port 0 I\/O pins 4-7; quasi-bidirectional<\/td><\/tr><tr><td>13<\/td><td>INT<\/td><td>Interrupt output; active low, asserts on input change<\/td><\/tr><tr><td>14-17<\/td><td>IO1.0-IO1.3<\/td><td>Port 1 I\/O pins 0-3; quasi-bidirectional<\/td><\/tr><tr><td>18<\/td><td>VDD<\/td><td>Power supply (2.3 V to 5.5 V)<\/td><\/tr><tr><td>19-22<\/td><td>IO1.4-IO1.7<\/td><td>Port 1 I\/O pins 4-7; quasi-bidirectional<\/td><\/tr><tr><td>23<\/td><td>SCL<\/td><td>I2C serial clock; requires external pull-up resistor<\/td><\/tr><tr><td>24<\/td><td>SDA<\/td><td>I2C serial data; requires external pull-up resistor<\/td><\/tr><\/table>","application_scenarios":"<ul><li><strong>GPIO Expansion<\/strong>: Adding 16 digital I\/O lines to a microcontroller using only I2C SDA\/SCL pins<\/li><li><strong>Keypad Scanning<\/strong>: 4x4 matrix keypad interface with interrupt-driven change detection<\/li><li><strong>LED Control<\/strong>: Driving 16 status LEDs with individual on\/off control via I2C commands<\/li><li><strong>Industrial I\/O Modules<\/strong>: Remote digital input\/output expansion on factory floor I2C backplane<\/li><li><strong>Power Management<\/strong>: Controlling power enable signals and reading power-good status across multiple voltage rails<\/li><\/ul>","alternative_models":"<table><tr><th>Model<\/th><th>Manufacturer<\/th><th>Bits<\/th><th>Interface<\/th><th>INT<\/th><th>Package<\/th><\/tr><tr><td>PCA9539PW<\/td><td>NXP<\/td><td>16<\/td><td>I2C<\/td><td>Yes<\/td><td>TSSOP-24<\/td><\/tr><tr><td>MCP23017<\/td><td>Microchip<\/td><td>16<\/td><td>I2C<\/td><td>Yes<\/td><td>SSOP-28<\/td><\/tr><tr><td>PCF8575<\/td><td>NXP\/TI<\/td><td>16<\/td><td>I2C<\/td><td>Yes<\/td><td>SOIC-24<\/td><\/tr><tr><td>TCA9539<\/td><td>Texas Instruments<\/td><td>16<\/td><td>I2C<\/td><td>Yes<\/td><td>TSSOP-24<\/td><\/tr><tr><td>MAX7317<\/td><td>Maxim\/ADI<\/td><td>10<\/td><td>SPI<\/td><td>Yes<\/td><td>QSOP-24<\/td><\/tr><\/table>\n<p>PCA9539BS is a 16-bit I2C GPIO expander from NXP in HVQFN24 (4x4mm) with interrupt and reset. The PCA9539PW is the TSSOP-24 version still in production. PCA9555 provides similar 16-bit I\/O with internal pull-up resistors in DIP-24\/TSSOP-24. For lower pin count, PCA9536 offers 4-bit I2C GPIO in TSSOP-8. MAX7326 from ADI provides 16-bit I2C GPIO with hot-insertion support. MCP23017 from Microchip offers 16-bit I2C GPIO with configurable interrupt outputs.<\/p>"},"_links":{"self":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/8031","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=8031"}],"version-history":[{"count":0,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/8031\/revisions"}],"wp:attachment":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/media?parent=8031"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/categories?post=8031"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/tags?post=8031"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=8031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}