Datasheet

11
4337K–USB–04/08
AT89C5130A/31A-M
AVDD PWR
Analog Supply Voltage
AVDD is used to supply the on-chip PLL and the USB PAD.
-
VSS GND
Digital Ground
VSS is used to supply the buffer ring and the digital core.
-
UVSS GND
USB Digital Ground
UVSS is used to supply the USB pads.
-
UCAP PWR
USB Pad Power Capacitor
UCAP must be connect to an external capacitor for USB pad power supply
(for typical application see
Figure 4-1 on page 12)
-
VDD PWR
Digital Supply Voltage
VDD is used to supply the buffer ring on all versions of the device.
It is also used to power the on-chip voltage regulator of the Standard
versions or the digital core of the Low Power versions.
-
VREF O
USB pull-up Controlled Output
VREF is used to control the USB D+ 1.5 kΩ pull up.
The Vref output is in high impedance when the bit DETACH is set in the
USBCON register.
-
Table 3-12. Power Signal Description (Continued)
Signal
Name Type Description
Alternate
Function