Chapter 10 Regulator; Block Diagram Of Regulator And Usb Driver/Receiver - NEC switch User Manual

The µ PD789800 incorporates a regulator that powers the USB driver/receiver. The features are as follows.
• Generates V (3.3 ±0.3 V) from V
REG
• Supports power-saving mode, reducing power consumption in mode.
Figure 10-1. Block Diagram of Regulator and USB Driver/Receiver
RXD
SEP
SEM
TXDP
TXDM
TXEN
RXEN
Cautions 1. To stabilize the V
2. Connect the pull-up resistor (1.5 kΩ Ω Ω Ω ) for the USBDM pin to the REGC pin.
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CHAPTER 10
, V (4.0 to 5.5 V) and outputs it to the REGC pin.
DD0 DD1
µ
PD789800
V
DD0
V
REG
Regulator
V
SS0
V
DD0
USB driver/
receiver
V
SS0
voltage, connect the REGC pin to V
REG
User's Manual U12978EJ3V0UD
REGULATOR
REGC
1.5 kΩ
USBDM
USBDP
via 22 µ µ µ µ F capacitor.
SS
µ
22 F
V
SS
Hub