Device description
The RTR6285/RTR6280 device is a highly integrated radio frequency complementary metal oxide semiconductor (RF CMOS) transceiver IC.
The functional block diagram for the RTR6285 IC is shown in Figure 1-1 and the functional block diagram for the RTR6280 IC is shown in Figure 1-2.

The RTR6285/RTR6280 IC supports multi-band, multi-mode phones.
■ Receiver paths:
   ❒ GSM/EDGE 850
   ❒ GSM/EDGE 900
   ❒ GSM/EDGE 1800
   ❒ GSM/EDGE 1900
   ❒ Two single-ended UMTS inputs
   ❒ Two differential UMTS inputs
   ❒ Three single-ended UMTS diversity inputs (RTR6285 only)
   ❒ GPS receive (RTR6285 only)
■ Transmitter paths:
   ❒ Two low-band Tx paths for:
      – GSM/EDGE 850
      – GSM/EDGE 900
      – UMTS 800/850/900
   ❒ Three high-band Tx paths for:
      – GSM/EDGE 1800
      – GSM/EDGE 1900
      – UMTS 1700/AWS/1800
      – UMTS 1900
      – UMTS 2100
     
Numerous secondary functions also are integrated on-chip:
■ LNAs for UMTS Rx operation
■ Quadrate demodulator to support UMTS Rx operation
■ Three fractional-N synthesizers with on-chip VCOs and loop filters:
   ❒ PLL1 and on-chip VCO support all transmitters of GSM 850/900/1800/1900 and
      UMTS low and high bands. It also serves all receivers of GSM
      850/900/1800/1900.
   ❒ PLL2 and on-chip VCO support primary and diversity receivers of UMTS high
      and low bands.
   ❒ PLL3 and on-chip VCO support GPS receiver (RTR6285 only).
■ Transceiver LO generation and distribution circuits:
   ❒ GSM/EDGE 850/900/1800/1900 Rx
   ❒ GSM/EDGE 850/900/1800/1900 Tx
   ❒ UMTS high and low bands primary and diversity Rx
   ❒ UMTS high and low bands Tx
■ Quadrature modulators to support GSM/GPRS/EDGE polar Tx and
   WCDMA/HSDPA Tx operations
■ Integrated power detector
■ Analog support functions
■ Reference signal for the Mobile Station Modem™ (MSM™) device transmit DACs
■ Transmit gain control
■ Bias control
■ Digital control circuits and interfaces
■ Single-line serial bus interface (SSBI)
■ Thermometer for temperature measurement