Pinout and Pin Description

STV0674

32/35

5.4

External circuits

5.4.1

Crystal oscillator

There are 2 crystal oscillator pins XTAL_IN, XTAL_OUT, as shown in

architecture is a single stage oscillator with an inverter working as an amplifier. The oscillator stage

is biased by an internal resistor (>1M

Ω). It also requires an external PI network consisting of a

crystal and two capacitors.

Note:

The clock accuracy of the oscillator circuit must be within the USB compliance data signaling rate

tolerance of 12.000Mb/s ± 0.25%.

5.4.2

Audio

If the record audio section of the STV0674 is not required, AP, CBS, VC and AN can be left

unconnected. VDDA must however be connected to a 3V3 supply.

5.4.3

Recommended power supply decoupling

A 0.1µF bypass capacitor located as close as possible to the chip package connecting between all

VDD pins and GND and at least one bulk decoupling capacitor on each of the supply rails VDDA,

VDDC, VDDI and VDDP.

Figure 16: Oscillator support circuit

Figure 17: Audio PLL filter and CBS

15pF

XTALO

15pF

XTALI

Crystal

680 pF

VC

10nF

10K

10µF

CBS

+

-