PCA9561PW,118

Specialized Overview

The PCA9561PW,118 is a 20-pin CMOS device featuring four 6-bit non-volatile EEPROM registers and six hardware pin inputs. It provides a 6-bit multiplexed output to replace DIP switches or jumpers for system configuration. The component supports Mobile and Desktop VID Configuration by bypassing CPU-defined values to set processor voltage for various performance or sleep modes. It operates on an I2C-bus/SMBus interface with a maximum clock frequency of 400 kHz. The supply voltage range is 3.0 V to 3.6 V, and it functions within an ambient temperature range of -40 °C to +85 °C.

Specialized Feature Summary

• Includes four internal non-volatile EEPROM registers allowing five independent settings via four registers and one external hardware pin set.
• Features a 6-bit 5-to-1 multiplexer that selects between internal register contents and external hardware inputs for the MUX_OUT pins.
• Supports I2C-bus/SMBus communication with 5 V and 2.5 V tolerant inputs/outputs for flexible integration.
• Provides hardware write protection via the WP input to control access to the non-volatile registers.

Specialized Applications

• Mobile and Desktop VID (Voltage IDentification code) Configuration
• Laptop computer Speed Step configuration
• Server and telecommunications/networking system configuration

Specialized Procurement Notes

Verify the specific ordering suffix '118' corresponds to the Reel pack, SMD, 13-inch packing method as documented in the official NXP datasheet. Confirm the package type is TSSOP20 (SOT360-1). Ensure the operating temperature range requirement matches the specified -40 °C to +85 °C for this part number.

Specialized Selection Notes

Select this component when replacing physical DIP switches or jumpers with a software-configurable solution. It is suitable for applications requiring multiple preset voltage configurations without power cycling. Consider the 400 kHz I2C speed and 3.0 V to 3.6 V supply voltage constraints during system design.

Specialized Part Context

The PCA9561 is part of the I2C-bus EEPROM DIP switch family from NXP Semiconductors. It succeeds older devices like the PCA9559 and PCA9560 by offering four internal non-volatile registers instead of one or two. This allows for more precise tuning of processor voltage settings across different operational modes.

Specialized Replacement Considerations

The PCA9561 is directly pin-compatible with the PCA9559. It can replace the PCA9559 without software modifications, though the PCA9561 offers additional non-volatile storage capacity.

Specialized FAQ

How does the PCA9561 handle data retention during power loss?

The non-volatile memory retains the most current setting selected before the power is turned off. Internal write-protection ensures data integrity if VDD drops below normal operating levels.

Can the I2C-bus override the MUX_SELECT pin?

Yes, the I2C-bus can override the MUX_SELECT pin in selecting the output source for the MUX_OUT pins.

What is the function of the WP pin?

The Write Protect (WP) input controls the ability to write content to the non-volatile registers. A logic 0 allows writing, while a logic 1 prevents updates to the EEPROM.