RF6001_1 RFMD [RF Micro Devices], RF6001_1 Datasheet - Page 51

• Manufacturer Part Number: RF6001_1
• Description: FRACTIONAL-N RF SYNTHESIZER WITH MODULATOR AND DIGITAL IF FILTER
• Manufacturer: RFMD [RF Micro Devices]

Clock Outputs
The OSCO output may be used to drive the RF2722, or it can provide the system clock for the radio. The OSCOM pin deter-
mines the frequency of the buffered OSCO output signal. If OSCOM is low, the output signal is 13MHz. When OSCOM is high,
the output signal is 26MHz.
The RF2722 may also be provided a 26MHz clock from the LDTO pin by setting the DC_CLK bit true. This will output a 26MHz
clock via the LDTO pin for an amount of time set by DC_TIME3 after RXEN is asserted.
Additional circuitry is included to prevent glitches, or incomplete pulses on the OSCO buffered output pin. This circuitry requires
a few stable clock cycles before the output is enabled.
VCO’s
The internal power VCO’s on the RF6001 are completely integrated and controlled by the on-chip Fractional-N PLL. Both low-
band (VCO1) and high-band (VCO2) RF outputs can be matched to 50Ω with a single series capacitor. VCO1 requires external
inductors to ground of approximately 2.2nH with ±5% tolerance and Q>30 on pins 25 and 26. Using standard FR4 material
(DK=4.25@1GHz, loss tangent=0.014) the inductor physical dimensions can be printed according to the table below based
on the distance from top layer metal to RF ground plane:
The output of the VCO’s should be connected to the transmit buffers located in the RF2722, as shown in the diagram below:
Rev A3 DS050929
Inductance (nH)
2.5
2.5
2.5
2.5
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DAC2
TCXO
Line Width (mils)
10
10
10
10
OSCA
Crystal Oscillator Circuit
*
OSCB
Generation
Line Length (mils)
Part of the POLARIS™ TOTAL RADIO™ Solution
Clock
*Crystal used:
Toyocom PN TSX-8A,
NDK PN 4025DA
350
250
210
190
Internal Clocks
To host/DSP,
and/or RF2722
OSCO
Gnd Plane Spacing (mils)
RF6001
10
15
20
5
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