QUALCOMM
CDMA
TECHNOLOGIES
H T T P : / / W W W. C D M AT E C H . C O M
ENABLING THE FUTURE OF COMMUNICATIONS
TM
4
MSM6500
™
CHIPSET SOLUTION
RFT6100 Device Description
The RFT6100 device is a direct conversion
chipset that integrates all the upconversion
and modulation functionality necessary for
CDMA and FM-mode phones operating in
cellular and PCS bands. This transmit chip
consists of two I/Q modulators, one for cellular
and one for the PCS band. The baseband I/Q input from the MSM
directly modulates the cellular or PCS carrier derived from the
respective LO generation circuit.
Both the cellular and PCS output drive their own variable gain
amplifier (VGA) with a gain control range of 85 dB. A final cellular
driver amplifier provides a modulated RF output.
To accommodate split band and filtering, the PCS VGA drives two
output amplifiers that can be selected independently or
simultaneously via an input selectable switch. All RF outputs have
fully integrated 50-ohm matching networks. Integrated on the
RFT6100 is the receiver phase locked loop (PLL), the transmit
PLL, and the entire transmit VCO including resonant components.
The VCO drives the LO generation block, which in turn generates
the required local-oscillator signal for all CDMA bands of
operation.
RFT6100 Device Features
• Reduction in component count, space and cost via radioOne
chipset that eliminates receiver and transmitter IF
• Single- or dual-band operation: cellular and PCS
• Single- or multimode operation:
– Cellular FM
– Cellular CDMA
– PCS CDMA
• Full direct upconversion from analog baseband to RF
• Transmit signal path:
– Baseband amplifier
– Two-quadrature modulator/upconverter
– RF AGC amplifier, switch network, driver amplifier
• Integration of LO generation circuit
• Requirement of only one external VCO for all CDMA bands of
operation
• Entire transmit synthesizer on chip (transmitter PLL and VCO)
• Receiver PLL on chip
• Greater than 85 dB transmit power control range
• Power-reduction feature via MSM control extends handset talk time
– Optimized for low DC power consumption versus RF output level
– Transmit puncturing
– Selective circuit power down
• Efficient three-line QCT Serial Bus Interface (SBI)
• Power supply voltage (2.7 to 3.0 V)
• Small thermally efficient package (40-pin BCC++)
QUANTUM [ QUANTUM RESEARCH GROUP ]
