Receiver - Nokia NSB-5 Series Technical Documentation Manual

PAMS Technical Documentation
optimal performance.
SUMMA (N700) provides two main functions:
1. RX/TX blocks
2. PLL
The receiver includes a Receive Controlled Gain Amplifier, a mixer with LO buffers and IF
amplifiers. The transmitter section includes a Transmit Controlled Gain Amplifier, an I/Q
Modulator, circuitry required to generate the Quadrature Local Oscillator and Transmit
Power Control which controls the MMIC PA (N500) output power.
The PLL section is control via a serial bus and contains both UHF and VHF PLL
and predividers.
The MMIC PA (N500) uses gallium–arsenide heterojunction bipolar transistor (GaAs HBT)
technology. The PA has an overall dynamic range of 45dB, and is capable of producing
32.5dBm output power with 0dBm input.
Interfacing with the above ASICs are four more ASICs. These include:
1. CCONT (N100)– is a multifunction power management IC. This ASIC contains six 2.8V
linear regulators used in the RF section as well as two 2.8V regulators used in the BB
section. CCONT also contains a switch mode supply power which generates +5V which is
used to power the charge pumps in SUMMA. Some of the features of this IC are a nine
channel A/D converter, power up/down procedures, reset logic, charging control, watch-
dog, sleep control, and SIM interface.
2. COBBA_GJP (N300)– is an interface between the digital world of the BB processing
and the analog world of RF and audio circuitry.
3. MAD2_PR1 (D200) – contains system logic and DSP
4. CHAPS – charging control ASIC

Receiver

The receiver is a triple conversion receiver consisting of two ASICs; CRFU_2a (N600) and
SUMMA (N700). CRFU_2a contains LNA bias circuitry with an external transistor which
provides step gain, depending on the incoming RF level and the first and second mixers.
SUMMA contains the third mixer. All filtering is external.
The received RF signal from the antenna is fed via the duplex filter (3 pole bandpass fil-
ter; Z502) to the LNA. LNA input and output matching networks are external. The LNA
gain step is controlled by MAD2_WD1 (FRAC, D200). Gain step in LNA is activated when
the receive RF level is below –48 dBm.
Following the LNA, the signal is fed to a 3 pole ceramic bandpass filter (Z602). The com-
bination of the duplex filter and the bandpass filter define the blocking characteristics of
the receiver.
Issue 1 03/01
Nokia Mobile Phones Ltd.
NSB-5
System Module
Page 55