Motorola A840 - Cell Phone - CDMA2000 1X, Service Manual, Page: 22 / 56

22 June 07, 2004
Theory of Operation A840
Phase-locked loop circuits:
• PLL#1 and an on-chip VCO supports cdma2000 TX modes
• PLL#2
Supports EGSM RX & TX, DCS RX &TX, and CDMA2000 RX modes using an
external VCO
Supports gpsone using the RFR6000 on-chip VCO
Transceiver LO generation and distribution circuits
• EGSM-900 RX and TX
• DCS-1800 TX and RX
• Cellular-TX
• PCS- TX
Analog support functions
• Reference signal of the MSM transmit DACs
• Transmit gain control
• Bias control
• Digital Interfaces
• 3 –line serial bus interface ( SBI)
• Dedicated RF_ON ( TX_ON) control line
The device is fabricated using an advanced SiGe BiCMOS process that accommo-
dates high-frequency, high-precision analog circuits as well as low-power CMOS
functions. Designed to operate with 2.7 to 3.0 Volt power supplies, it is compatible
with single-cell Li-Ion batteries.
RTR6300 is available in a small, thermally efficient package (48 BCCP)
RFR6000 Overview
The RFR6000 is an RF-to-Baseband receiver IC, an integral component of QUAL-
COMM’s radioOne
TM
Zero-IF chipset. All radioOne ICs are highly integrated and
fulfill specific functions; functional requirements are partitioned between the ICs
to yield complete, optimal transceiver implementations. Overall radioOne perfor-
mance depends on the combined, complementary performance of all the ICs in the
chipset.
The RFR6000 IC provides the zero-IF receiver signal path, from RF to analog
Baseband, for multi-band, multi-mode handsets including combinations of the
following:
Bands:
• Cellular bands
• PCS bands
• GPS band
Modes:
• AMPS-FM
• CDMA (known as IS-95, cdmaOne, IS-98, cdma2000, 1x EV-DO)
• gpsOne TM