Panasonic DP-MB310EU Service Manual page 259

KX-MB2230EU/ KX-MB2270EU/ KX-MB2515EU/ KX-MB2545EU/ KX-MB2575EU/ DP-MB310EU
USB (Universal Serial Bus) block
Description
This is a USB block for data communication with PC.
Two signal lines (D+/D-) are differential signals which work in reverse phase.
VBUS: CN300/CN301 1pin
D-: CN300/CN301 2pin
D+: CN300/CN301 3pin
GND: CN300/CN301 4pin
Circuit Diagram
Sequence of normal operation
Connection with the PC
When USB cable from PC is connected to CN300, VBUS voltage goes up to 5V, and IC300 recognize the connection with PC.
Then D+ becomes about 3V: waveform (1)-1
The D+ becomes 0V, then communication between IC300 and PC is started: waveform (2)-1
When a few seconds elapsed after USB cable was inserted into CN300,the unit enters stand-by mode.
When PC is at Hi-Speed, waveforms are (1)-1 ~ (1)-4.
When PC is at Full Speed, waveforms are (2)-1 ~ (2)-4.
Connection with the USB memory
When connected MB2500 and USB memory, through 1pin of CN77, 5V is supplied to the USB memory.
Then D+ becomes about 3V: waveform (1)-1.
The D+ becomes 0V, then communication between IC300 and USB memory is started: waveform(2)1.
When USB memory is Hi-Speed, waveform are (1) ~ (1)-4.
When USB memory is Full-Speed, waveform are (2) ~ (2)-4.
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