TCA9538PWR - 8-Bit 1.65-5.5V I/O Expander | Texas Instruments
MPN: TCA9538PWR ✓ AktifTCA9538PWR Ringkasan
An I/O expander is a peripheral interface device that increases the number of inputs and outputs available to a central controller. Positioned between the host processor and external logic, an I2C expander uses serial control lines to configure and monitor multiple parallel ports. This expands the I2C bus > interface IC > peripheral interface > semiconductor hierarchy without requiring additional direct GPIO pins on the host.
The device provides 8 configurable general-purpose I/O bits, allowing each line to function as an input or output according to the port configuration register. The TCA9538 also includes an interrupt output for input-state changes, hardware reset control, and two hardware-selectable address inputs. These features support deterministic control of sensors, relays, logic gates, indicators, and other peripheral hardware over a shared serial bus.
The TCA9538 supports both 100 kHz Standard-mode and 400 kHz Fast-mode I2C operation. Its 1.65 V to 5.5 V operating range covers low-voltage embedded systems as well as 5 V industrial and commercial equipment. Two address-selection pins allow up to four TCA9538 devices on the same bus when the surrounding system has sufficient address and interrupt-routing resources.
Typical applications include industrial control panels, programmable logic controllers, sensor-hub boards, motor and relay interfaces, LED status panels, and compact embedded control systems. The eight-port architecture is especially useful when a host needs additional digital lines for sensors, switches, and discrete outputs without expanding the host package.
Designers should follow the manufacturer datasheet when assigning the I2C address, configuring input or output direction, selecting pull-up resistors, and routing the interrupt signal. Careful pin assignment is important because changing a port from input to output can affect external pull networks, and the interrupt path must remain compatible with the host's interrupt topology.
This page combines manufacturer specifications, application guidance, drop-in alternatives, and practical interface design considerations to support component selection and PCB implementation.
Pilihan pengganti yang segera untuk TCA9538PWR — sama paket, pin-pin kompatibel. Bahagian paket yang berbeza memerlukan kerja ulang PCB diasingkan.
Varietas dalam siri ini
Model serupa yang kompatibel dengan pengganti yang segera TCA9538PWR (sama faktor bentuk dan kaki) — berbeza dalam Configuration Registers, Number of I/O Ports, Product Type, Package, Interrupt Output.
PCA9538DWR
✅ Masuk Drop-InHubungi untuk harga
Lihat Datasheet →PCA9557PWR
✅ Masuk Drop-InHubungi untuk harga
Lihat Datasheet →PCA9535PWR
✅ Masuk Drop-InHubungi untuk harga
Lihat Datasheet →TCA6408PWR
✅ Masuk Drop-InHubungi untuk harga
Lihat Datasheet →PCA9534PWR
✅ Masuk Drop-InHubungi untuk harga
Lihat Datasheet →TCA9538PWR Spesifikasi
| Product Type | 8-bit I2C/SMBus I/O expander |
| Number of I/O Lines | 8 lines |
| Supply Voltage Range | 1.65 V to 5.5 V |
| Maximum I2C Clock Frequency | 400 kHz |
| Supported I2C Modes | 100 kHz Standard-mode and 400 kHz Fast-mode |
| Interface Protocol | I2C and SMBus |
| Interrupt Output | Yes |
| Reset Register | Yes |
| Configuration Registers | Yes |
| Hardware Address Inputs | 2 address inputs |
| Maximum Devices per I2C Bus | 4 devices |
| Gambaran Suhu Operasi | -40 °C to 125 °C |
| Kemasan | 16-pin TSSOP |
| Jenis Pemasangan | Surface mount |
| Status RoHS | Compliant |
Konfigurasi Pin TCA9538PWR
| Pin 1 | A0 — Address input A0 |
| Pin 2 | A1 — Address input A1 |
| Pin 3 | RESET — Active-low reset input |
| Pin 4 | INT — Interrupt output |
| Pin 5 | P0 — General-purpose I/O port 0 |
| Pin 6 | P1 — General-purpose I/O port 1 |
| Pin 7 | P2 — General-purpose I/O port 2 |
| Pin 8 | P3 — General-purpose I/O port 3 |
| Pin 9 | GND — Ground connection |
| Pin 10 | P4 — General-purpose I/O port 4 |
| Pin 11 | P5 — General-purpose I/O port 5 |
| Pin 12 | P6 — General-purpose I/O port 6 |
| Pin 13 | P7 — General-purpose I/O port 7 |
| Pin 14 | SCL — I2C serial clock |
| Pin 15 | SDA — I2C serial data |
| Pin 16 | VCC — Power supply connection |
Aplikasi Biasa
TCA9538PWR patut untuk 6 aplikasis: Industrial Control Panels, PLC and Embedded Control Modules, Sensor Hub and Conditioning Board, LED Status and Indicator Panels, Relay and Discrete Output Control, Compact Test and Measurement Interfaces.
Industrial Control Panels
The TCA9538PWR is well suited to industrial control panels that need many discrete status inputs and outputs without expanding the host controller. Its eight configurable lines can monitor panel switches, selector positions, and alarm inputs while driving indicator or relay-driver logic. The 1.65 V to 5.5 V supply range supports low-voltage control systems, while 400 kHz Fast-mode operation permits efficient register access. The interrupt output can notify the host of an input change, reducing the need for continuous polling. Before finalizing the interface, verify logic thresholds, output loading, reset polarity, and the controller's I2C pull-up arrangement against the manufacturer datasheet.
PLC and Embedded Control Modules
The TCA9538PWR adds eight parallel I/O lines to compact PLC peripherals and embedded control modules through the I2C bus. This is useful when a controller has limited GPIO capacity but must operate solenoids, pushbuttons, isolators, or discrete logic inputs. Its interrupt feature allows the host to respond to changed input states, while reset and configuration registers support deterministic initialization. The 16-pin TSSOP package supports compact board layouts, although careful budgeting of connector space and trace routing remains essential. Firmware must account for the direction and polarity settings stored in the configuration register and must service interrupt sources using the register sequence documented by the manufacturer.
Sensor Hub and Conditioning Board
The TCA9538PWR can provide discrete digital interfaces for a sensor-hub board where sensors or signal-conditioning circuits need individual enable, mode, or fault lines. Its eight independent I/O bits reduce the pin count required on a sensor gateway or condition-monitoring controller. Because the expander can operate down to 1.65 V, it is suitable for low-power sensing systems whose host operates at a similarly low voltage. The device does not perform analog measurement, so sensor outputs requiring amplification or conversion must use suitable external components. Use the interrupt output for latch-style fault events and confirm whether a given external line needs a pull-up, pull-down, or push-pull driver when configuring the port direction.
LED Status and Indicator Panels
The TCA9538PWR can organize an LED status panel by controlling multiple indicators through a compact serial interface. Its eight output bits are suitable for grouped user-interface LEDs, equipment-status lamps, or isolated alarm displays when the selected LED arrangement respects the electrical output limits. This arrangement leaves more host GPIO pins available for displays, communication, and control functions. The 400 kHz Fast-mode I2C rate allows the controller to update multiple port states efficiently, provided the system updates the output register in a deliberate sequence. Validate LED current, grounding, switching behavior, and any shared ground requirements before use. If an indicator must remain active during reset, review the reset behavior and required external pull networks.
Relay and Discrete Output Control
The TCA9538PWR can serve as the logic-control layer for relay drivers, latches, and discrete output stages in embedded equipment. Eight configurable outputs can address grouped loads, while the host manages the required operating sequence over I2C. The interrupt input supports change-driven monitoring, and the 1.65 V to 5.5 V range permits operation across common embedded supply levels. The expander should normally drive transistor, MOSFET, or relay-driver inputs rather than high-current coils directly. Confirm per-pin sourcing and sinking limits, inductive transient requirements, isolation boundaries, and fault-state behavior in the manufacturer datasheet and the external driver design.
Compact Test and Measurement Interfaces
The TCA9538PWR can extend a compact test or measurement instrument with controls for front-panel switches, status indicators, fixture enables, or programmable test-point gates. Its small TSSOP footprint and eight-port organization allow additional interface functions to be added without increasing the pin count of the main controller. The device's 400 kHz I2C capability supports efficient command and status transfers, and the interrupt output can report asynchronous fixture events. For laboratory equipment, consider grounding, isolation, electrostatic-discharge protection, and creepage requirements around exposed connectors. The manufacturer datasheet should define the electrical limits and timing assumptions used in the final input and output network.
Data referensi kejuruteraan untuk TCA9538PWR — perbandingan, panduan rancangan, dan maklumat kesediaan
Panduan Pilihan
Perbandingan dengan Gantian
| Parametr | Produk Ini | PCA9538DWR | PCA9557PWR | PCA9535PWR | TCA6408PWR | PCA9534PWR |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | NXP | NXP | NXP | Texas Instruments | NXP |
| Package | 16-pin TSSOP | 16-pin TSSOP - same | 16-pin TSSOP - same | 16-pin TSSOP - same | 16-pin TSSOP - same | 16-pin TSSOP - same |
| Number of I/O Lines | 8 lines | 8 lines | 8 lines | 8 lines | 8 lines | 4 lines - 50% fewer |
Penyeberangsung Jelas
- Eight configurable lines with interrupt support (vsTCA6408PWR)
- Identical line count to the closest NXP candidate (vsPCA9538DWR)
- Twice the I/O count of PCA9534PWR (vsPCA9534PWR)
Catatan Desain
Place the TCA9538PWR close to the I2C bus and the devices it controls. Keep SCL and SDA traces short, route them away from switching nodes and high-current edges, and provide the pull-up resistors specified for the system voltage and bus capacitance. Confirm pin 1 orientation against the TSSOP marking. If several expanders share the bus, route each interrupt output separately or combine the relevant signals only through an approved circuit.
Do not assume that similar 16-pin TSSOP I/O expanders are register-compatible. Compare address selection, active-low reset polarity, interrupt operation, power-on defaults, port-direction behavior, and every command used by the firmware. A footprint-compatible candidate can still require schematic or software changes if it lacks the interrupt output, uses different address pins, or exposes different control registers.
Check each output's voltage, source current, sink current, and total package-current limit before assigning loads. Use the datasheet's recommended input and output decoupling arrangement and keep I2C pull-up current within the device and host-controller limits. External LEDs, relays, and inductive drivers should use suitable current-limiting or transistor stages rather than assuming all eight outputs can drive loads directly.
Validate the complete bus network at the intended 100 kHz or 400 kHz operating rate. Consider trace capacitance, connector loading, pull-up resistance, voltage margin, and the capacitance of the host and peripheral devices. A bus that works reliably in a short bench setup can fail on a longer PCB or cable, particularly when the operating voltage or pull-up arrangement is changed.
Maklumat Kesediaan
RoHS compliance is indicated by the Mouser product listing. The available manufacturer and distributor information does not establish REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status.