AMIS-52000 Datasheet, PDF (14/15 Pages) AMI SEMICONDUCTOR – Single-Chip Radio Transceiver

AMIS-52000 Single-Chip Radio Transceiver
Data Sheet
X1, X2, Crystal Oscillator
The AMIS-52000 requires a parallel resonant crystal. The
frequency of this crystal can be in the frequency range of
12.5MHz to 14.5MHz. The AMIS-52000 will form an RF
frequency for transmit and receive from this crystal
frequency. The transmit frequency is 32 times the crystal
frequency. The receive frequency is the same, but the AMIS-
52000 will pull the frequency to form an LO (local oscillator)
frequency about 50kHz different than the signal frequency.
A typical value for the 2 parallel load capacitors is 15pF. This
may be less than the suggested values for a crystal due to
the internal trim capacitance of the AMIS-52000.
The AMIS-52000 contains a QUICK START function. For the
frequencies that this circuit can operate (350 to 480MHz),
the circuit can be used to stabilize the crystal frequency
much faster than the normal crystal oscillator circuit. This
Power-On-Reset/Brownout Detection
The POR/Brownout Detection circuit ensures that the AMIS-
52000 will be in a reset state when VDD drops below
certain threshold voltage, and remains in this state until
VDD rises above another threshold voltage. The POR circuit
characteristics are illustrated in Figure 13.
Figure 12 – Typical Crystal Oscillator Circuit
function is explained in detail in AMIS application note,
“AMIS-52000 Quick Start Crystal Oscillator Circuit
Operation and Setup.”
Figure 13 – Power On Reset Characteristics
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