DESCRIPTION
The PCA9561 is a 20-pin CMOS device consisting of four 6-bit non-volatile EEPROM registers, 6 hardware pin inputs and a 6-bit multiplexed output. It is used for DIP switch-free or jumper-less system configuration and supports Mobile and Desktop VID Configuration, where 5 preset values (4 sets of internal non-volatile registers and 1 set of external hardware pins) set processor voltage for operation in various performance or battery conservation sleep modes. The PCA9561 is also useful in server and telecom/networking applications when used to replace DIP switches or jumpers, since the settings can be easily changed via I2C/SMBus without having to power down the equipment to open the cabinet. The non-volatile memory retains the most current setting selected before the power is turned off.

FEATURES
• Selection of non-volatile register_n as source to MUX_OUT pins via I2C-bus
• I2C-bus can override MUX_SELECT pin in selecting output source
• 6-bit 5-to-1 multiplexer DIP switch
• 4 internal non-volatile registers
• Internal non-volatile registers programmable and readable via I2C-bus
• 6 open drain multiplexed outputs
• 400 kHz maximum clock frequency
• Operating supply voltage 3.0 V to 3.6 V
• 5 V and 2.5 V tolerant inputs/outputs
• Useful for Speed Step configuration of laptop
• 2 address pins, allowing up to 4 devices on the I2C-bus
• MUX_IN values readable via I2C-bus
• ESD protection exceeds 200 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101
• Latch-up testing is done to JESDEC Standard JESD78 which exceeds 100 mA.