AK9223 Datasheet, PDF (10/16 Pages) Asahi Kasei Microsystems – Dual 1-Bit, 10MHz, 2nd-Order, Modulat

[AK9223]
■ Internal Operation
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.
■ Modulator
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.
■ Digital I/F
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.
014010283-E-01
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2015/01