Electrical characteristics

VL6522

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6.4

AC electrical characteristics

6.4.1

USB2.0 interface

Conforms to the USB2.0 chapter 7.1.

6.4.2

External crystal

The primary reason for choosing the crystal frequency and tolerance is because of the USB

data rate. To comply with the USB2.0 specification, when in high speed mode (480 Mb/s),

the bit accuracy has to be +/- 500 ppm.

It is recommended to use a crystal with a frequency of 12 MHz and a frequency accuracy of

+/- 100 ppm or better.

6.4.3

RESETN

After RESETN is pulsed low (during power up for example), the device shall start up in it’s

default condition. This will include reading the EEPROM, if fitted.

During startup, the RESETN line should be held low for between 100 µs and 50 ms after the

supplies are stable. On the reference design board, an RC circuit is used to delay the rise of

RESETN using values of 470 k

between VDD3IO reaching 3 V and the device coming out of reset.

6.4.4

the device over usb, the SDA & SCL pins can be controlled. This allows the slaving of such

interface can be found in section

4.3.2.