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Texas Instruments PCF8575DB
- Part No.:
- PCF8575DB
- Manufacturer:
- Texas Instruments
- Category:
- I/O Expanders
- Package:
- 24-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
PCF8575DB.pdf
- Description:
- IC XPNDR 400KHZ I2C SMBUS 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:164
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Product details
Overview
PCF8575DB from Texas Instruments is a 16-bit I²C/SMBus I/O expander with open-drain interrupt output, quasi-bidirectional ports (P00–P07, P10–P17), 400 kHz I²C bus support, and 2.5 V to 5.5 V operation. It enables remote GPIO expansion in space-constrained industrial controllers and telecom equipment where microcontrollers lack sufficient native I/O.
For engineers reviewing the PCF8575DB datasheet, PCF8575DB pinout, PCF8575DB application, or PCF8575DB equivalent, this page delivers verified electrical specs, package-confirmed pin functions, real-world use cases for server management and industrial automation, and two validated alternative parts with documented functional differences.
Technical Context
The PCF8575DB implements a latch-based quasi-bidirectional I/O architecture-each port pin operates as input or output without direction control, defaulting high at power-on via internal current source (IOH). Its interrupt logic triggers on any edge transition of input-mode pins and resets upon read/write acknowledgment or port state restoration.
I²C communication requires even-byte transfers: first byte maps to P07–P00, second to P17–P10; address is set by A0–A2 hardware pins (8 possible addresses). No internal configuration registers exist-the device responds directly to I/O data writes/reads after target address transmission.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I²C Clock Frequency | 400 kHz maximum - supports Fast Mode I²C timing without external clock stretching. |
| Supply Voltage Range | 2.5 V to 5.5 V - interoperable with 3.3 V and 5 V microcontroller systems without level shifters. |
| Standby Current | ≤10 μA - enables low-power remote monitoring in always-on telecom shelters and servers. |
| Output Sink Current | 25 mA per pin at VOL = 0.4 V - drives LEDs directly without external transistors. |
| Interrupt Response Time | tiv = 4 μs - ensures rapid notification of port state changes to host MCU. |
| ESD Protection | HBM: 2000 V - meets industrial robustness requirements per JESD22-A114. |
| Operating Temperature | –40 °C to +85 °C - qualified for embedded industrial and telecom infrastructure environments. |
Pinout & Package
PCF8575DB uses a 24-pin SSOP (Shrink Small Outline Package) with 8.2 mm × 7.8 mm footprint and 0.65 mm lead pitch. Pin numbering follows standard top-view orientation with pin 1 at top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| INT (Pin 1) | Open-drain interrupt output | Signals port-level edge transitions to host MCU; requires external pull-up to VCC. |
| A0–A2 (Pins 21, 2, 3) | Hardware I²C address inputs | Set 3-bit slave address (0x40–0x4E); no pull-ups needed - direct VCC/GND connection suffices. |
| P00–P07 (Pins 4–11) | Quasi-bidirectional I/O port 0 | Each pin latches output state and sources/sinks current; defaults high at power-on. |
| P10–P17 (Pins 13–20) | Quasi-bidirectional I/O port 1 | Functionally identical to P0x; paired with P0x for 16-bit parallel expansion. |
| SCL / SDA (Pins 22 / 23) | I²C serial clock / data | Require external pull-up resistors; support standard and Fast Mode I²C protocols. |
| VCC / GND (Pins 24 / 12) | Power supply / reference | Operates across 2.5–5.5 V; decoupling capacitor recommended near VCC pin. |
Key Features
| Feature | Design Value |
|---|---|
| Quasi-bidirectional I/O architecture | Eliminates need for separate direction-control signals - simplifies firmware and reduces MCU pin count. |
| Latched outputs with high-current drive | 25 mA sink capability per pin enables direct LED driving without external buffers or transistors. |
| Edge-triggered open-drain interrupt | Reduces polling overhead - host MCU wakes only on actual port activity, lowering system power consumption. |
| Hardware-configurable I²C address | A0–A2 pins allow up to eight PCF8575DB devices on one bus - scalable for multi-peripheral rack-mounted systems. |
| No internal configuration registers | Direct I/O mapping eliminates register initialization code - accelerates bring-up and reduces firmware complexity. |
Applications
| Server Management | Industrial PLC I/O Expansion |
|---|---|
Use Scenario: Monitoring fan status, temperature sensors, and power supply health in 1U rack servers. IC Role / Device Role / Timing Role: Remote I/O expander providing 16 additional GPIOs for sensor interface and status reporting over I²C. Use Value: Reduces host CPU GPIO load while enabling hot-swap detection and fault logging via interrupt-driven reads. | Use Scenario: Adding digital input/output capability to compact programmable logic controllers in factory automation. IC Role / Device Role / Timing Role: Quasi-bidirectional port extender interfacing with limit switches, solenoids, and indicator lamps. Use Value: Supports direct 25 mA sink for 24 V DC outputs and edge-triggered interrupts for real-time event capture. |
| Telecom Shelter Filter Control | Embedded PC Peripheral Interface |
Use Scenario: Controlling RF filter banks and monitoring environmental sensors in outdoor telecom base station shelters. IC Role / Device Role / Timing Role: I²C-connected remote I/O node managing analog switch control lines and fault flag inputs. Use Value: Withstands –40 °C to +85 °C ambient and delivers <10 μA standby current for battery-backed monitoring. | Use Scenario: Extending GPIO for USB hub status LEDs, card-detect signals, and reset controls in mini-ITX motherboards. IC Role / Device Role / Timing Role: Low-voltage (3.3 V) I/O expander sharing SMBus with other platform controller hub peripherals. Use Value: Compatible with SMBus 2.0 timing and supports hardware address selection to avoid bus conflicts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I/O expander applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA9555DBR | Same 16-bit quasi-bidirectional I/O, but includes programmable polarity inversion and configurable interrupt latching. | Required where input polarity must be inverted per-pin or interrupt persistence is needed beyond edge detection. | Choose PCA9555DBR if firmware requires per-port input polarity control or non-resetting interrupt behavior. |
| PCF8574ATDBR | 8-bit version with identical pinout, voltage range, and I²C interface; lacks interrupt output and has lower drive strength (20 mA). | Suitable for simpler peripheral interfaces where 8 I/Os suffice and interrupt signaling is handled externally. | Choose PCF8574ATDBR when board space or cost constraints justify halving I/O count and omitting interrupt functionality. |
Compared with PCA9555DBR and PCF8574ATDBR, the PCF8575DB offers the optimal balance of interrupt-driven responsiveness, 16-bit scalability, and minimal firmware overhead - making it ideal for real-time industrial monitoring where deterministic latency and low code footprint are critical.
Availability
PCF8575DB is available at Aetrix Electronics and suitable for server management, industrial PLC I/O expansion, and telecom shelter filter control requiring stable component supply across extended product lifecycles.
Supply support for PCF8575DB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and communications markets.
The PCF8575DB belongs to TI's I²C peripheral interface portfolio, designed specifically to simplify remote GPIO expansion in resource-constrained embedded systems with strict power and layout constraints.
FAQ
What is the I²C address range supported by the PCF8575DB?
The PCF8575DB supports eight fixed I²C slave addresses (0x40–0x4E) determined by hardware connections to A0, A1, and A2 pins. Each combination sets a unique 7-bit address - for example, A2=A1=A0=GND yields 0x40 (write) / 0x41 (read). No software address configuration is required, and addresses align with PCF8574 and PCA9535 families for bus compatibility.
Does the PCF8575DB require external pull-up resistors on SCL and SDA lines?
Yes, the PCF8575DB requires external pull-up resistors on both SCL and SDA lines to VCC. The datasheet specifies typical values of 10 kΩ for standard-mode and 2.2 kΩ for Fast-mode (400 kHz) operation. Pull-ups ensure proper signal rise time and bus contention handling; omission causes communication failure or intermittent ACK errors.
How does the PCF8575DB handle I/O direction control?
The PCF8575DB uses a quasi-bidirectional architecture with no explicit direction register. Writing '1' to a port bit configures it as an input (enabled internal current source pulls high); writing '0' configures it as an output (active pull-down). Input mode requires prior write of '1' - reading returns the external pin state only if the output driver is off.
What is the maximum sink current per I/O pin on the PCF8575DB?
The PCF8575DB supports up to 25 mA sink current per I/O pin at VOL = 0.4 V (VCC = 5.5 V), and 15 mA at VOL = 1.0 V. This allows direct driving of standard LEDs and small relays. Total device sink current must not exceed 100 mA, and simultaneous full-load operation across all 16 pins is electrically prohibited per absolute maximum ratings.
Can the PCF8575DB operate at 2.5 V supply voltage?
Yes, the PCF8575DB is fully specified for 2.5 V to 5.5 V operation. At 2.5 V, it maintains 400 kHz I²C timing compliance, ≤10 μA standby current, and 10 mA minimum sink current per pin (VOL = 0.4 V). All electrical characteristics-including interrupt response (tiv = 4 μs) and ESD ratings-are guaranteed across this full voltage range.
PCF8575DB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-SSOP (0.209", 5.30mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Number of I/O:
- 16
- Interface:
- I2C, SMBus
- Interrupt Output:
- Yes
- Features:
- POR
- Output Type:
- Push-Pull
- Current - Output Source/Sink:
- 10mA, 25mA
- Clock Frequency:
- 400 kHz
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SSOP
PCF8575DB FAQ
1.How can I place an order for PCF8575DB through Aetrix?
Please submit a Request for Quotation (RFQ) for PCF8575DB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for PCF8575DB reliable?
The price and inventory of PCF8575DB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCF8575DB is usually 5 days.
3.What payment methods are accepted for PCF8575DB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCF8575DB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCF8575DB?
PCF8575DB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCF8575DB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for PCF8575DB?
For technical support, including PCF8575DB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCF8575DB requirements.
6.How does Aetrix verify that PCF8575DB is sourced from the original manufacturer or authorized distributors?
All PCF8575DB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that PCF8575DB meets industry standards.
7.What is the process for return or replacement of PCF8575DB?
All PCF8575DB units undergo pre-shipment inspection (PSI). If there is an issue with PCF8575DB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The PCF8575DB part is unused and in its original packaging.
Return procedure for PCF8575DB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PCF8575DB Tags
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TCA6408ARSVR
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onsemi
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PCF8574ADWR
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TCA9554PWR
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TCA9555RTWR
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TCA9535PWR
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