PCA9549D,112

Specialized Overview

The PCA9549D,112 is an octal bus switch manufactured by NXP USA Inc., housed in a 24-lead SO24 plastic small outline package (SOT137-1). It provides eight bits of high-speed TTL-compatible bus switching controlled via the I²C-bus. The device operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies from 0 Hz to 400 kHz. It features low ON-state resistance, with typical values of 8 Ω at 4.5 V–5.5 V and 12 Ω at 3.0 V–3.6 V. The component includes an active LOW reset input, three hardware address pins allowing up to eight devices on the same bus, and ESD protection exceeding 2000 V HBM.

Specialized Feature Summary

• Eight individually controllable bidirectional channels for I²C/SMBus signal routing
• Active LOW reset input for recovering from stuck bus conditions
• Three address pins enabling multiple devices on a single bus line
• Low standby current and no glitch on power-up

Specialized Applications

• I²C bus multiplexing and demultiplexing
• System management bus (SMBus) isolation
• Voltage translation between different bus domains

Specialized Procurement Notes

Verify the specific ordering suffix ',112' against official documentation, as the provided datasheet lists 'PCA9549D' without this suffix. Confirm package type SO24 matches design requirements. Check current product status, as related variants may be discontinued.

Specialized Selection Notes

Select this component when eight independent I²C switches are required in a standard SOIC footprint. Ensure the system voltage falls within the 2.3 V to 5.5 V range. Verify that the 400 kHz fast-mode speed meets communication requirements.

Specialized Part Context

This part belongs to the PCA954x family of I²C-controlled bus switches. Other variants include PCA9549PW (TSSOP24) and PCA9549BS (HVQFN24), offering the same functionality in different packages. The family also includes lower channel counts like the PCA9545 (4-channel) and PCA9543 (2-channel).

Specialized Replacement Considerations

Direct package replacements include PCA9549PW and PCA9549BS. Functional equivalents with fewer channels are PCA9545D and PCA9543D.