PCA9535DB - 16-Bit I2C/SMBus GPIO Expander | Texas Instruments
MPN： PCA9535DB ✓ 啟用中PCA9535DB 概覽
An I/O expander is an interface IC that adds parallel digital input or output capability to a serial bus system. The PCA9535DB belongs to the I/O expander hierarchy within interface ICs, enabling a host microcontroller to control or monitor multiple lines while reducing the number of host GPIO pins required. Its I2C-compatible interface makes it suitable for systems using embedded processors, industrial controllers, communication equipment, and consumer electronics.
The PCA9535 offers 16 I/O pins, 2.3 V to 5.5 V operation, 400 kHz bus support, low standby-current consumption, and a dedicated interrupt output. Each port can be configured as input or output through the device registers, allowing mixed input/output designs on the same expander. The configuration registers also support device-level and port-level control, making the device useful for systems requiring distributed digital I/O.
Compared with a microcontroller dedicated to GPIO expansion, the PCA9535DB offloads repetitive parallel I/O handling to a low-power serial peripheral. Its 16-bit architecture reduces the number of external connections, while the interrupt line allows the host to respond to input changes without continuously polling every port. The I2C and SMBus interface also simplifies integration with widely adopted embedded buses.
Typical applications include industrial control panels, keypad and LED scanning, remote sensor interfaces, programmable logic controllers, communication modules, and consumer products requiring additional GPIO. The PCA9535DB is particularly useful when a design requires bidirectional digital lines, change notification, or bus-addressed peripheral control.
For PCB implementation, place the device close to the supported connector or controlled signal group and route I2C SDA and SCL away from noisy power paths. Confirm the device address configuration and account for pull-up requirements in the complete bus design. This page combines verified manufacturer and distributor information, package details, commercial guidance, practical design notes, and drop-in replacement considerations for engineers evaluating the PCA9535DB.
直接替換替代品，適用於 PCA9535DB — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PCA9535DB （相同外形與佔位） — 差異在於 Interrupt Output, Device Type, Package, Interface, Packaging.
PCA9535DBR
✅ 直接替換聯絡詢價
查看資料表 →PCA9535CDB
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
PCA9555DB
✅ 直接替換聯絡詢價
查看資料表 →PCA9535DW
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PCA9535DBG4
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
PCA9535DB 規格
| Device Type | Remote 16-bit I2C/SMBus low-power I/O expander |
| Number of I/O | 16 |
| Supply Voltage Range | 2.3 V to 5.5 V |
| I2C/SMBus Clock Frequency | 400 kHz |
| 介面 | I2C/SMBus |
| Interrupt Output | Yes |
| Configuration Registers | Yes |
| I/O Direction Control | Programmable input/output |
| Standby Current Consumption | 1 uA maximum |
| 封裝 | 24-SSOP (0.209, 5.30 mm width) |
| Packaging | Tube |
PCA9535DB 24-ssop (0.209, 5.30 mm width) 腳位配置指南
PCA9535DB（24-ssop (0.209, 5.30 mm width) 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： PCA9535DB.
請參閱 資料表 以查看完整腳位配置。
典型應用
PCA9535DB 適用於 6 應用s: Industrial Control Panels, LED and Keypad Scanning, Remote Sensor and Actuator Interface, Programmable Logic Controller I/O, Communication Equipment, Consumer and Embedded Products.
Industrial Control Panels
The PCA9535DB fits industrial control panels that need more digital lines than the host controller can expose directly. Its 16 I/O pins can drive status indicators, read pushbuttons, or operate relay-control inputs while the I2C/SMBus interface remains the central communication path. The 2.3 V to 5.5 V operating range supports common industrial logic levels, and the interrupt output lets the controller react to changed inputs instead of continuously polling. Because the verified data does not specify the temperature range, qualification status, or exact output-current limits, the final component selection must be checked against the enclosure environment and load requirements.
推薦
LED and Keypad Scanning
The PCA9535DB is suitable for LED and keypad scanning designs where a compact controller needs additional parallel outputs and inputs. Its 16 configurable I/O lines can be assigned across display, indicator, and switch functions, while the 400 kHz I2C/SMBus interface provides a practical shared-bus rate for embedded products. The interrupt output can identify a key or input change so the host can update the display more efficiently. The 24-SSOP package supports compact layouts, but external current limiting, LED drive limits, debouncing, and bus pull-up components must be selected from the final electrical design.
推薦
Remote Sensor and Actuator Interface
The PCA9535DB can bridge a serial bus host to remote digital sensors, actuators, and discrete interface signals. Sixteen configurable lines allow a design to mix input sensing and output control, and the interrupt output provides event notification for line-state changes. The 2.3 V to 5.5 V supply range and 400 kHz bus compatibility fit many embedded monitoring systems. The supplied sources do not verify the exact I/O drive current or input thresholds, so engineers must confirm signal-level compatibility, grounding, isolation requirements, and cable length before using the device with remote sensors.
推薦
Programmable Logic Controller I/O
The PCA9535DB is appropriate for programmable logic controller and embedded automation modules that need compact, bus-addressed parallel I/O. Its 16 I/O lines can expand discrete input channels and command outputs while retaining a straightforward I2C/SMBus connection to the controller. The interrupt output supports event-driven handling of input transitions, reducing unnecessary polling and helping maintain system responsiveness. Its 24-SSOP package and 2.3 V to 5.5 V operating range are attractive for compact control hardware, although production designs must confirm operating temperature, output loading, and isolation requirements against the verified manufacturer datasheet.
推薦
Communication Equipment
The PCA9535DB can add supervisory and control lines to communication equipment that uses an I2C/SMBus management interface. Sixteen configurable ports may monitor module-present, reset, fault, or enable signals and control local status indicators or peripheral enables. The 400 kHz bus rate supports normal embedded management traffic, while the interrupt output enables event-driven fault reporting. The low-power design and 2.3 V to 5.5 V range are useful in equipment with constrained power budgets. Exact logic thresholds, output-drive capability, and package temperature limits are not supplied in the verified snippets and must be confirmed before deployment.
推薦
Consumer and Embedded Products
The PCA9535DB is useful in consumer and embedded products that need miscellaneous digital I/O without dedicating many host-controller pins. It can control display-enable signals, read configuration switches, operate status LEDs, or monitor service inputs through a shared 400 kHz I2C/SMBus bus. The interrupt output allows efficient response to user or service events, and the 24-SSOP package supports compact board layouts. Designers should account for external pull-ups on SDA and SCL, define a unique device address, and verify the 2.3 V to 5.5 V supply compatibility with every attached peripheral. The verified data does not provide RoHS, REACH, or halogen-free declarations.
推薦
推薦產品摘要
工程參考資料，適用於 PCA9535DB — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | PCA9535DBR | PCA9535CDB | PCA9555DB | PCA9535D | PCA9535DBG4 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 24-SSOP | 24-SSOP - same package family | 24-SSOP - same package family | 24-SSOP - same package family | 24-SSOP - same package family | 24-SSOP - same package family |
| Device Type | 16-bit I2C/SMBus low-power I/O expander | PCA9535 family 16-bit I/O expander | PCA9535 family 16-bit I/O expander | 16-bit I/O expander | PCA9535 family 16-bit I/O expander | PCA9535 family 16-bit I/O expander |
| Number of I/O | 16 | 16 | 16 | 16 | 16 | 16 |
主要差異化特點
- Low-power PCA9535 implementation (對比PCA9555DB)
- Directly documented same-family ordering candidate (對比PCA9535DBR)
- Event-driven host integration (對比PCA9535PW)
設計說明
Confirm the complete power architecture before layout. The verified device range is 2.3 V to 5.5 V, and the PCA9535 removes the internal I/O pull-up resistor found on the PCA9555. Do not assume that a PCA9555 design can be substituted without reviewing external pull-ups on the I/O lines. Provide local supply decoupling close to the device and keep the I2C pull-up network consistent with the system voltage and bus capacitance.
Keep the 24-SSOP footprint and pin numbering consistent with the exact orderable variant used for production. PCA9535PW is a TSSOP-related option in the cross-reference results and is not a guaranteed drop-in replacement for the PCA9535DB SSOP footprint. Before substituting any listed alternative, compare land patterns, pin-1 orientation, exposed connections, device address, and all register behavior against the current manufacturer datasheet.
Route SDA and SCL as short, continuous traces away from switching nodes and high-current output paths. The supported 400 kHz bus rate is reasonable for ordinary embedded systems, but margin depends on bus capacitance, pull-up strength, trace length, and the number of connected devices. Use the interrupt output for event-driven responses rather than polling continuously, and verify the polarity and masking behavior against the datasheet.
合規資訊
The supplied verified web data does not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements.
