PCA9535DBR - 16-Bit I2C I/O Expander | Texas Instruments
N.º de pieza: PCA9535DBR ✗ Fin de vidaPCA9535DBR Descripción general
An I/O expander is an interface IC that translates serial commands into parallel digital input or output operations. The PCA9535DBR belongs to the I/O expander hierarchy within interface controllers and system interface ICs. Its remote port architecture allows a controller to monitor inputs and control outputs located behind cables, bus isolators, or other serial links, reducing the number of host GPIO pins required on compact industrial, embedded, and communications equipment.
The device operates from 2.3 V to 5.5 V and supports I2C and SMBus communication at up to 400 kHz. Sixteen I/O pins can be configured individually as inputs or outputs through configuration registers. An interrupt output provides a change-event indication, while the configuration registers retain port settings. The verified distributor information also identifies a maximum standby current of 1 uA, helping reduce power consumption when the system is inactive.
Internally, the PCA9535 consists of two 8-bit I/O port groups connected to the serial interface. Each port provides eight configurable lines, creating a total of 16 I/O resources. The pin-to-pin and I2C address compatibility stated by Texas Instruments relative to the PCF8575 does not mean that existing firmware is always portable, because the enhanced register behavior requires software changes. This distinction is important when planning a replacement or driver migration.
Typical uses include remote control panels, industrial automation modules, sensor and relay interfaces, embedded control boards, and communications equipment. The device is particularly useful when a system needs more GPIO lines than the host controller provides or when the controlled signals are physically remote from the processor. The 24-pin SSOP package also makes it practical for compact boards requiring a conventional leaded surface-mount footprint.
When designing a circuit, account for the I2C pull-up resistors, bus capacitance, address selection, and the electrical requirements of every attached port. Check that connected loads remain within the device's output-current and absolute-maximum ratings. Although the PCA9535DBR and its alternatives may use related interfaces, firmware must be checked for register-map differences, input polarity, and interrupt behavior before substitution.
This product record combines the verified manufacturer and distributor details with package, purchasing, replacement, and application guidance. It is intended to support faster part identification while clearly separating confirmed PCA9535DBR specifications from parameters that still require confirmation from the manufacturer datasheet.
Alternativas directas para PCA9535DBR — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con PCA9535DBR (mismo factor de forma y huella) — difiere en Package, Interface, Interrupt Output, Packaging, Device Type.
TCA9535DBR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TCA9555DBR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
PCA9535DB
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCA9535DBQ
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
PCAL9535A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
PCA9535DBR Especificaciones
| Number of I/O Lines | 16 lines |
| Interfaz | I2C and SMBus |
| Supply Voltage Range | 2.3 V to 5.5 V |
| Maximum Bus Clock Frequency | 400 kHz |
| Interrupt Output | Yes |
| Configuration Registers | Yes |
| Maximum Standby Current | 1 uA |
| Encapsulado | 24-SSOP (0.209 inch, 5.30 mm width) |
| Tipo de montaje | Surface mount |
| Packaging | Cut Tape |
| I/O Port Organization | Two 8-bit ports, 16 I/O total |
| Low-Power Operation | Low standby-current operation |
| Host GPIO Reduction | 16 host I/O lines |
Guía de configuración de pines de PCA9535DBR 24-ssop (0.209 inch, 5.30 mm width)
Configuración de pines para PCA9535DBR (encapsulado 24-ssop (0.209 inch, 5.30 mm width)). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para PCA9535DBR.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
PCA9535DBR es adecuado para 6 aplicacións: Industrial Automation Remote I/O, Server and Communications Control Panels, Sensor and Relay Interface Module, Remote Operator Panel, Embedded Data Acquisition System, Low-Power Sensor Hub.
Industrial Automation Remote I/O
The PCA9535DBR fits remote I/O modules because it adds 16 configurable digital lines over a 400 kHz I2C connection while operating from 2.3 V to 5.5 V. A controller can use the expander for pushbuttons, discrete sensor inputs, relay-control outputs, and panel status indicators without consuming 16 host GPIO pins. The interrupt output can signal a port change and reduce unnecessary polling. Confirm the output-current limits, industrial temperature range, and transient-protection requirements from the manufacturer datasheet before deployment.
Recomendado
Server and Communications Control Panels
PCA9535DBR is useful in communications and server-adjacent control panels where front-panel indicators, configuration switches, and status inputs require more parallel lines than the host processor can expose directly. Its 16-bit remote port, 2.3 V to 5.5 V supply range, and 400 kHz I2C mode provide a compact interface between the controller and panel circuitry. The interrupt function can alert the host to relevant input changes. Verify timing margin at the maximum bus rate and confirm the current limits for LED or logic loads.
Recomendado
Sensor and Relay Interface Module
The PCA9535DBR can bridge a microcontroller to external sensors, optocouplers, latches, and relay drivers when direct host GPIO capacity is limited. Each of the 16 lines can be assigned as an input or output through configuration registers, allowing one serial bus to handle both acquisition and command paths. With a 400 kHz interface and 2.3 V to 5.5 V operating range, it supports mixed embedded systems, but output drive current, inductive-load protection, and isolation must be designed around the exact electrical limits.
Recomendado
Remote Operator Panel
PCA9535DBR is well suited to a remote operator panel containing multiple pushbuttons, LEDs, selectors, and status lamps. The main controller configures the 16 ports over I2C, reads input states, and updates output indicators without requiring a dedicated GPIO header to each panel. Because the device supports 400 kHz operation and has a verified maximum standby current of 1 uA, it can also support power-conscious panels. Interface details such as debouncing, LED current, input polarity, and interrupt masking still need application-specific validation.
Recomendado
Embedded Data Acquisition System
The PCA9535DBR provides a simple way to collect discrete signals from a distributed acquisition board. Sixteen configurable inputs can represent alarms, threshold flags, module-presence signals, or sampled status lines, while the interrupt output identifies activity for the embedded controller. Its 2.3 V to 5.5 V supply range permits integration with both low-voltage and conventional 5 V logic when levels are compatible. Confirm the input voltage and leakage limits, then add suitable protection where field wiring exposes the board to transients.
Recomendado
Low-Power Sensor Hub
PCA9535DBR can extend a low-power sensor hub with configurable digital channels while preserving a compact serial footprint. Its verified 1 uA maximum standby current is useful when the hub spends most of its time idle, and the interrupt output permits wake-oriented control instead of continuous polling. The 2.3 V minimum operating voltage also supports low-voltage system rails. Use the configuration registers to minimize active current, confirm wake and reset behavior in the datasheet, and ensure attached sensors do not exceed the port drive limits.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para PCA9535DBR — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | TCA9535DBR | TCA9555DBR | PCA9535DB | PCA9535DBQ | PCAL9535A |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors |
| Package | 24-SSOP | 24-SSOP | 24-SSOP | 24-SSOP | 24-SSOP | 24-SSOP |
| Number of I/O Lines | 16 lines | 16 lines | 16 lines | 16 lines | 16 lines | 16 lines |
| Interface | I2C and SMBus | I2C | I2C | I2C and SMBus | I2C and SMBus | I2C |
Diferenciadores clave
- Low standby consumption (frente a PCA9555 family)
- Wide confirmed operating range (frente a PCAL9535A)
- Established Texas Instruments compatibility path (frente a PCA9535DB)
Notas de diseño
Do not treat package equivalence as proof that firmware is interchangeable. Texas Instruments states that the PCA9535 is pin-to-pin and I2C-address compatible with the PCF8575 but requires software changes because of enhancements. For every substitute, compare port configuration registers, input and output polarity, interrupt masking, reset values, addressing, and timing before releasing replacement firmware.
Use the confirmed 2.3 V to 5.5 V operating range to select the regulator and level-shift strategy for the PCA9535DBR. The verified maximum standby current is 1 uA, but total system power also depends on active current, pull-ups, and attached loads. Check the manufacturer limits for output drive and source current before using a port directly with LEDs, relays, or other non-light-load devices.
Place the I2C pull-up resistors at the physical end of the bus that requires the strongest pull-up, accounting for the bus length and capacitance. Keep the PCA9535DBR close to its intended connector or remote I/O circuitry when cable length is significant, and provide local return paths that reduce susceptibility to noise. The 400 kHz maximum bus rate must be validated against the complete wiring and peripheral load.
Información de cumplimiento
The supplied verified excerpts do not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is marked not applicable because no automotive qualification is identified for PCA9535DBR.
