PCA9545APWE4 Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
The Texas Instruments PCA9545APWE4 is a 4-channel I2C bus multiplexer and switch that allows one master to communicate with up to four separate I2C bus segments, with 60 dB off-state isolation and 45 Ω on-state resistance in a 20-pin TSSOP package. It includes an interrupt logic function to consolidate interrupt signals from multiple downstream buses. Available from $1.80 in stock with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 20
- Lifecycle
- OBSOLETE
- Datasheet
- PCA9545APWE4 Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 4-channel I2C bus switch with 60 dB channel-to-channel isolation prevents bus contention when mixing devices with conflicting addresses
- Interrupt consolidation logic merges INT signals from all four downstream channels to a single output for simplified host monitoring
- 20-pin TSSOP surface-mount package with selectable I2C address enabling up to eight devices on a single master bus
Applications
The PCA9545APWE4 is used in server motherboards and embedded computing modules where multiple I2C sensors or EEPROMs share the same device address and must be accessed independently on isolated bus segments. It is also found in industrial measurement systems connecting temperature sensors, DACs, and real-time clocks to a single I2C master without address conflicts. Display driver boards and multi-board enclosures use it to route I2C traffic to the correct subsystem module.
Specifications
| YTEOL | 0 |
| Analog IC - Other Type | SINGLE-ENDED MULTIPLEXER |
| JESD-30 Code | R-PDSO-G20 |
| Normal Position | NO/NC |
| Number of Channels | 4 |
| Number of Functions | 2 |
| Off-state Isolation-Nom | 60dB |
| On-state Resistance-Max (Ron) | 45Ω |
| Output | COMMON OUTPUT |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | TSSOP20,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE, THIN PROFILE, SHRINK PITCH |
| Peak Reflow Temperature (Cel) | 260 |
| Supply Current-Max (Isup) | 0.012mA |
| Supply Voltage-Max (Vsup) | 5.5V |
| Supply Voltage-Min (Vsup) | 2.3V |
| Supply Voltage-Nom (Vsup) | 2.5V |
| Surface Mount | YES |
| Switching | BREAK-BEFORE-MAKE |
| Technology | CMOS |
| Terminal Finish | NICKEL PALLADIUM GOLD |
| Terminal Form | GULL WING |
| Terminal Pitch | 0.65mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| HTS Code | 8542.39.00.60 |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
How many I2C channels does the PCA9545APWE4 support?
The PCA9545APWE4 supports four independent bidirectional I2C channels that can be switched individually or in combination, allowing a single I2C master to communicate with multiple devices that may share the same 7-bit address across different bus segments.
What is the off-state isolation of the PCA9545APWE4?
The PCA9545APWE4 provides 60 dB of off-state isolation between deselected channels and the master bus, which prevents capacitive loading from inactive bus segments from degrading signal integrity on the active channel.
Does the PCA9545APWE4 support interrupt handling?
Yes, the PCA9545APWE4 includes an interrupt input for each downstream channel and consolidates them into a single interrupt output to the master, allowing the host controller to determine which channel has a pending interrupt without polling each bus segment individually.
How is the I2C address of the PCA9545APWE4 configured?
The PCA9545APWE4 has three hardware address pins (A0, A1, A2) that can be pulled high or low to set one of eight possible I2C addresses, allowing up to eight PCA9545A devices to coexist on the same upstream I2C bus, expanding to 32 total downstream segments.
What are common alternatives to the PCA9545APWE4?
Common alternatives include the PCA9546A (also a 4-channel I2C switch from TI), the TCA9545A for extended temperature operation, and the NXP PCA9545A which is a pin-compatible equivalent, all providing the same 4-channel I2C multiplexing function with interrupt support.
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About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
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