micrf113 Micrel Semiconductor, micrf113 Datasheet - Page 11

• Manufacturer Part Number: micrf113
• Description: Qwikradio Ask Transmitter
• Manufacturer: Micrel Semiconductor

Functional Description
Figure 3 is a functional block diagram of the MICRF113
transmitter. The MICRF113 is best described as a phase
locked transmitter. The MICRF113 system is partitioned
into five functional blocks:
• Crystal oscillator
• PLL×32
• Power amplifier
• Enable control
• Under voltage detection
Crystal Oscillator
The
configuration, designed to accept crystals with frequency
from 9.375MHz to 14.0625MHz.
Functional Diagram
Micrel, Inc.
June 2008
reference
XTLOUT
XTLIN
oscillator
XTAL
Osc.
is
crystal-based
VDD
Figure 3. Functional Block Diagram MICRF113
PFD
Pierce
Under Voltage
Detect
PLL X 32
11
Charge
Divider
Pump
Crystal Oscillator Parameters for ASK Operation
Figure
configuration for ASK operation. The reference oscillator
is capable of driving crystals with ESR range from 20Ω
to 300Ω.
When the ESR of crystal is at 20Ω, the crystal parameter
limits are:
ESR 20Ω
Cpar 2 to 10pF
Cmo 10 to 40fF
Amplitude
Lock
VCO
4
shows
VSS
Control
Enable
a
PA
reference
oscillator
[phone]
M9999-060208
PAOUT
ASK
MICRF113
circuit