TCA9538DBR - 8-Bit I2C I/O Expander | Texas Instruments
Teilenummer: TCA9538DBR ✓ AktivTCA9538DBR Übersicht
An I/O expander is an interface IC that extends the number of digital input and output pins available to a host processor. The TCA9538 belongs to the I2C interface hierarchy, where the I2C or SMBus protocol links the expander to a controller such as a microcontroller. Each port can be configured as an input or output, allowing the same circuit to support switches, sensors, logic-control signals, LEDs, and other digital peripherals while conserving host pins and reducing interconnect complexity.
The principal operating parameters are an 8-bit port count, a 1.65 V minimum supply voltage, a 5.5 V maximum supply voltage, and support for a 400 kHz I2C bus. According to the Texas Instruments product page, the device also includes an interrupt output, reset control, and configuration registers. These functions support event-driven peripheral monitoring and orderly control of multiple downstream signals without continuous polling by the host processor.
The TCA9538DBR is a remote, low-power parallel-interface device rather than a general-purpose processor or transceiver. Its serial control path uses the two-wire I2C or SMBus interface, while the eight parallel ports connect to digital circuitry in the target system. The SSOP-16 package provides a compact surface-mount format, and the manufacturer lists the part as active. Its operating temperature range is -40 °C to +85 °C, supporting industrial-temperature equipment when correctly handled for thermal and soldering requirements.
Typical uses include control-panel backlights, sensor and switch interfaces, relay-control inputs, programmable logic interfaces, battery-powered monitoring equipment, and communication equipment requiring additional GPIO. The TCA9538 is especially useful when the host controller has limited spare pins but the system still needs eight independently configurable digital lines and an interrupt mechanism for status changes.
Design the bus with pull-up resistors appropriate for the operating voltage, confirm that the 400 kHz bus rate is compatible with the complete bus capacitance and every attached peripheral, and account for logic thresholds when the expander operates alongside mixed-voltage devices. Place the interface pins, supply decoupling, and pull-up network to minimize routing delay and maintain signal integrity across the board.
This product record combines the manufacturer’s electrical and package information with practical interface-selection guidance, pinout-location references, application analysis, and compatibility cautions. It also distinguishes true same-package drop-in replacements from related expanders that differ in footprint, voltage tolerance, interrupt behavior, or register implementation and therefore require engineering review before substitution.
Drop-in-Alternativen für TCA9538DBR – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Für dieses Produkt sind keine Drop-in-Alternativen verfügbar.
Alternativen anfordernTCA9538DBR Technische Daten
| Number of I/O Ports | 8 ports |
| Schnittstellentyp | I2C/SMBus |
| Operating Supply Voltage Range | 1.65 V to 5.5 V |
| Maximum I2C Bus Frequency | 400 kHz |
| Anzahl der Pins | 16 pins |
| Gehäuse | SSOP-16 (DB) |
| Montageart | Surface mount |
| Betriebstemperaturbereich | -40 °C to +85 °C |
| Interrupt Output | Yes |
| Reset Function | Yes |
| Configuration Registers | Yes |
| RoHS-Status | Compliant |
| Lebenszyklusstatus | Active |
TCA9538DBR ssop-16 (db) Pinbelegungsleitfaden
Pinbelegung für TCA9538DBR (ssop-16 (db)-Gehäuse). Pin-Nummerierung, Funktionen und Anschlussdiagramme sind im Herstellerdatenblatt definiert. Entnehmen Sie diesem den genauen Footprint und Lötrichtlinien.
Keine detaillierten Pinbelegungsdaten verfügbar für TCA9538DBR.
Siehe die Datenblatt für die vollständige Pin-Konfiguration.
Typische Anwendungen
TCA9538DBR ist geeignet für 6 Anwendungs: Control-Panel Indicator and Button Interface, Industrial Sensor and Discrete Signal Hub, LED and Relay Control Interface, Battery-Powered Monitoring Node, Communication Equipment Backplane Control, Programmable Control and Test Fixture.
Control-Panel Indicator and Button Interface
The TCA9538DBR is suitable for a control panel where a host controller must operate several LEDs, pushbuttons, or status indicators. Its eight configurable ports can reduce the number of GPIO pins required on the main processor, while the interrupt output allows the controller to react when an input state changes instead of continuously polling every signal. The 1.65 V to 5.5 V operating range supports both lower-voltage logic and conventional 5 V interfaces. Keep the I2C routing short, place pull-up resistors according to bus capacitance and voltage, and verify that LED current and polarity remain within the electrical limits shown in the manufacturer datasheet.
Industrial Sensor and Discrete Signal Hub
An industrial sensor interface can use the TCA9538DBR to aggregate up to eight digital signals from limit switches, proximity sensors, alarm lines, or discrete transducers. The expander communicates through I2C or SMBus at up to 400 kHz, leaving the primary controller free for computation and higher-level communications. Because the TCA9538DBR supports an interrupt output, the firmware can identify changed inputs without repeatedly reading the port register. Validate voltage thresholds at each sensor interface, provide appropriate protection for industrial wiring, and confirm that the bus remains within its capacitive and topology limits.
LED and Relay Control Interface
The TCA9538DBR can provide a compact parallel control layer for LEDs, relay drivers, latches, and other discrete loads connected to a host board. Its eight ports suit designs where adding direct GPIO to the processor would reduce routing flexibility or package density. The 1.65 V to 5.5 V range allows the interface to share a suitable system rail, although each connected driver must match that voltage and the current drawn by every output. Use the manufacturer’s electrical table to confirm per-port loading, and provide driver transistors or protection circuits wherever loads exceed the expander’s direct-drive capability.
Battery-Powered Monitoring Node
The TCA9538DBR fits monitoring nodes that acquire or supervise several low-speed digital signals without using a large microcontroller package. It operates down to 1.65 V, making it compatible with low-voltage embedded systems, and the interrupt function can support event-driven operation between periodic status updates. Power-budget analysis should account for the expander’s operating consumption, pull-up resistance, and attached sensors because every continuously high input can affect the input path. Select external resistor values to balance bus rise time against static current while retaining a valid 400 kHz bus waveform.
Communication Equipment Backplane Control
Within communication equipment, the TCA9538DBR can manage peripheral enables, fault indicators, module-present signals, and configuration GPIOs through the I2C/SMBus control path. The 400 kHz bus capability is appropriate for a short, well-controlled PCB bus, and the eight-port configuration helps consolidate several discrete control lines. Keep routing away from high-energy or high-current switching paths, observe rise-time and capacitance limits, and use the interrupt output for asynchronous events. The 16-pin SSOP package also supports compact board construction while retaining individual port control.
Programmable Control and Test Fixture
The TCA9538DBR can extend the control interface of a programmable test fixture by adding eight digital lines for fixture sensing or actuator commands. A controller can configure the ports, monitor their states, and use the interrupt output to react to fixture changes. The I2C/SMBus interface reduces the number of direct host connections and supports a common control architecture across multiple boards. For production test equipment, account for connector wiring, ESD protection, logic-level compatibility, and the maximum 400 kHz bus rate. Confirm the SSOP-16 footprint and pin assignments against the manufacturer package drawing before layout release.
Technische Referenzdaten für TCA9538DBR – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt |
|---|---|
| Brand | Texas Instruments |
| Package | SSOP-16 (DB) |
| Number of I/O Ports | 8 ports |
| Interface | I2C/SMBus |
| Operating Supply Voltage Range | 1.65 V to 5.5 V |
| Maximum I2C Bus Frequency | 400 kHz |
| Interrupt Output | Yes |
| Operating Temperature Range | -40 °C to +85 °C |
Wichtigste Unterscheidungsmerkmale
- Combines eight ports with an integrated interrupt path (vs. PCA9538DGVR)
- Supports both I2C and SMBus control (vs. PCA9538DGVR)
- Supports a 400 kHz serial bus (vs. PCA9538DGVR)
Designhinweise
Route SDA and SCL as a short, continuous two-wire bus with the device and pull-up resistors positioned according to the system’s physical topology. Avoid routing the bus across plane splits or between noisy power stages. The TCA9538DBR supports up to 400 kHz, but rise time must also satisfy every attached peripheral and the total bus capacitance. Check the schematic for a single defined I2C address and avoid adding pull-ups that exceed the allowed loading when several devices share the bus.
Place the required supply-decoupling capacitor close to the power and ground pins, and keep the return path short to reduce switching and shared-ground noise. The device operates from 1.65 V to 5.5 V, so logic thresholds, pull-up voltage, attached peripherals, and the host supply must share a compatible voltage plan. Confirm whether the selected configuration requires a pull-up to 3.3 V or 5 V rather than tying the bus to the wrong rail.
Do not treat any similarly named 8-bit expander as a drop-in replacement without checking package dimensions, exposed-pad or lead geometry, pin names, address selection, register behavior, interrupt polarity, reset polarity, and output-current limits. In particular, the TCA9538DBR uses a 16-pin SSOP package, so a different package suffix or a 10-pin device can prevent physical installation even when the functional description appears similar.
Compliance-Informationen
The manufacturer product page and the listed electronic-component comparison identify the TCA9538DBR as RoHS compliant and active. No automotive qualification is claimed.
