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RF6001
Rev A3 DS050929
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Part of the POLARIS™ TOTAL RADIO™ Solution
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 50
Ω 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:
Inductance (nH)
Line Width (mils)
Line Length (mils)
Gnd Plane Spacing (mils)
2.5
10
350
5
2.5
10
250
10
2.5
10
210
15
2.5
10
190
20
OSCA
Clock
Generation
OSCO
OSCB
TCXO
Internal Clocks
To host/DSP,
and/or RF2722
DAC2
Crystal Oscillator Circuit
*Crystal used:
Toyocom PN TSX-8A,
NDK PN 4025DA
*
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