[AK9223]

014010283-E-01

10

2015/01

The analog input of the AK9223 is composed by SC (switched-capacitor) circuits and this modulator block

digitizes analog inputs to 1-bit data stream. The clock source can be external or internal oscillator output.

Analog input is sampled by the modulator and compared with the reference voltage of the REFI pin. A

digital stream that represents the analog input voltage over time appears at the output of the

corresponding converter.

The AK9223 can be operated in two modes. Internal oscillation is used for the operation clock of the

modulator by setting the SEL pin =

“H”. In this case, the internal clock is fixed to 20MHz. When the SEL

pin is set to

“L”, modulator clock is externally input to the CLKI pin. In both of modes, the clock is internally

divided by two and functions as the modulator clock. When using an external clock, available input clock

range is from 1MHz to 24MHz. In this case, the modulator operates of a clock from 500kHz to 12MHz.

Analog input signals are converted with the modulator input clock. The OUT pin outputs the result of AD

conversion. The common clock that is used for two modulators is output from the CLKO pin. When the

SEL pin

= “H”, the CLKI pin must not be allowed to float but should be connected to DVDD or VSS5.