Device Architecture
2-20 Revision 4
RC Oscillator
The RC oscillator is an on-chip free-running clock source generating a 100 MHz clock. It can be used as
a source clock for both on-chip and off-chip resources. When used in conjunction with the Fusion PLL
and CCC circuits, the RC oscillator clock source can be used to generate clocks of varying frequency
and phase.
The Fusion RC oscillator is very accurate at ±1% over commercial temperature ranges and and ±3%
over industrial temperature ranges. It is an automated clock, requiring no setup or configuration by the
user. It requires only that the power and GNDOSC pins be connected; no external components are
required. The RC oscillator can be used to drive either a PLL or another internal signal.
RC Oscillator Characteristics
Table 2-9 • Electrical Characteristics of RC Oscillator
Parameter Description Conditions Min. Typ. Max. Units
F
RC
Operating
Frequency
100 MHz
Accuracy Temperature: 0°C to 85°C
Voltage: 3.3 V ± 5%
1%
Temperature: –40°C to 125°C
Voltage: 3.3 V ± 5%
3%
Output Jitter Period Jitter (at 5 k cycles) 100 ps
Cycle–Cycle Jitter (at 5 k cycles) 100 ps
Period Jitter (at 5 k cycles) with
1 KHz / 300 mV peak-to-peak noise
on power supply
150 ps
Cycle–Cycle Jitter (at 5 k cycles) with
1 KHz / 300 mV peak-to-peak noise
on power supply
150 ps
Output Duty Cycle 50 %
I
DYNRC
Operating Current 1 mA
