TC9293F/FN/N

2003-06-27

7

5. DA Conversion Circuit

The 2’nd order

Σ-∆ modulation system DA converter for 2 channels (simultaneous output type) has been

incorporated.

2’nd order

∑-∆ modulator: Y (Z) = X (Z) + (1 − Z−1)2Q (Z)

It has been designed that clock for the

Σ-∆ modulator is a half of master clock (MCK: crystal oscillation

clock) and the converter operates at 192 fs at the standard operation.

The noise shaping characteristic is shown below.

6. Output Circuit

These ICs is built-in 2’nd order analog low pass filter.

These output is analog signal directly, RQ (pin 5) and LO (pin 9) pins.

Figure 6 Construction of

ΣΣΣΣ-∆

∆∆

∆ Modulation DA Converter

Figure 7 Noise Shaping Characteristic

Figure 8 Analog Filter Circuit