Nokia 9000i, Service Manual

Page: 65 / 434

After Sales
Technical Documentation
RAE/RAK–1N
Baseband
Page 2–39
Original, 08/96
Table 40. External Signals and Connections, Outputs
Signal Name Signal description To
DAX Data acknowledge ASIC
AFC Automatic frequency control voltage RF
TXC TX transmit power control voltage / RX AGC voltage RF
TXQP,TXQN differential TX quadrature signal RF
TXIP,TXIN differential TX in–phase signal RF
PDATA0 LNA gain reduction RF
Table 41. External Signals and Connections, Bidirectional
Signal Name Signal description To/From
RFIDA(11:0) 12–bit data bus ASIC
Block description
The RFI provides A/D conversion of the in–phase (RXI) and quadrature
(RXQ) signals in receive path. It has 12 bit A/D converters and the output
sample rate is 541.667 kHz.
Analog transmit path includes 8 bit D/A converters to generate the
in–phase (TXI) and quadrature (TXQ) signals. RFI has differential outputs
for TXI and TXQ. The sample rate is 1.0833 MHz.
There is an 11 bit D/A converter for automatic frequency correction (AFC).
The sample rate is 1.3542 kHz.
Power ramp (TXC) is done with 10 bit D/A converter. The sample
frequency is 1.0833 MHz. This converter is also used for AGC during
receive slots.
The PDATA0 signal is used for LNA gain reduction in strong field
conditions. The rest of the AGC control is analog. The analog AGC (used
in receive) is multiplexed with the TXC signal (used in transmit).
The RFI has 12 bit data bus to the ASIC. The registers in the RFI are
accessed using 4 address bits. Control and clock signals are coming from
the ASIC.
The RFI has external 4.096 V voltage reference.
Main components
– RFI ASIC, physically in MCM2
– 4.096 V external voltage reference LM4040 (V420)