Rainbow Electronics AT83C5127 User Manual
Page 5
5
AT83C5127
7519A–SCR–04/05
D+
29
29
DVCC
I/O
USB Positive Data Upstream Port
This pin requires an external serial resistor of 33
Ω and a 1.5 K
Ω
pull-
up to
V
REF for full speed configuration.
D-
28
28
DVCC
I/O
USB Negative Data Upstream Port
This pin requires an external serial resistor of 33
Ω
V
REF
30
30
AVCC
O
USB Voltage Reference: 3.0 <
V
REF < 3.6 V
V
REF
can be connected to D+ through a 1.5 K
Ω
resistor. The
V
REF
voltage is controlled by software.
XTAL1
14
14
VCC
I
Input to the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal or an external oscillator must be
connected to this pin.
XTAL2
15
15
VCC
O
Output of the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal circuit must be connected to
this pin. If an external oscillator is used, leave XTAL2 unconnected.
PLLF
26
26
AVCC
O
PLL Low Pass Filter input
Receives the RC network of the PLL low pass filter.
AVCC
27
27
PWR
Analog Supply Voltage
AVCC is used to supply the internal 3.3V analog regulator which
supplies the internal USB driver
VCC
12
12
PWR
Supply Voltage
VCC is used to supply the internal 3.3V digital regulator which
supplies the PLL, CPU core and internal I/O’s
LI
10
10
PWR
DC/DC Input
LI supplies the current for the charge pump of the DC/DC converter.
- LI tied directly to VCC : the DC/DC converter must be configured in
regulator mode.
- LI tied to VCC through an external 10µH coil : the DC/DC converter
can be configured either in regulator or in pump mode.
CVCC
9
9
PWR
Card Supply Voltage
CVCC is the ouput of internal DC/DC converter which supplies the
Smart Card Interface. It must be connected to an external decoupling
capacitor of 10 µF with the lowest ESR as this parameter influences
on the CVCC noise
DVCC
1
1
PWR
Digital Supply Voltage
DVCC is the output of the internal analog 3.3V regulator which
supplies the USB driver. This pin must be connected to an external
680nF decoupling capacitor if the USB interface is used.
CVSS
11
11
GND
DC/DC Ground
CVSS is used to sink high shunt currents from the external coil
VSS
8
8
GND
Digital Ground
VSS is used to supply the PLL, buffer ring and the digital core
AVSS
25
25
GND
Analog Ground
AVSS is used to supply the USB driver.
Table 1. Pin Description (Continued)
Port
LQ
FP3
2
QF
N32
Internal
Power
Supply ESD
I/O
Reset
Level
Alt
Reset
Config
Conf 1
Conf 2
Conf 3
Led