Nokia Mobile Phones NSE-5 Series Service Manual page 77

PAMS
Technical Documentation
Interfacing
The interfacing between RF and BB is comprised of the signals stated
below.
SCLK Clock for the PLL Serial Programming (3.25 MHz)
SDATA Data for the PLL Serial Programming
SENA1 Latch Enable for the PLL Serial Programming
FRACTRL Front–end Amplifier Control - Turns the gain in the LNA on and
off
BAND_SEL Band Selection - Selects between GSM 900 and GSM 1800, i.e. it
turns on the respective mixers and LNAs in the CRFU3.
RXC Receiver Gain Control - The control voltage for the AGC amplifi-
er.
AFC Automatic Frequency Control Signal for the VCTCXO
RFC A high stability clock signal for the logic circuits (13 MHz)
RXINN, RXINP The differential RX signals to baseband
TXC Transmitter power Control signal, that controls the shape of the
burst.
TXP Transmitter Power enable ??
TXIN, TXIP Differential In–phase TX baseband signals for the RF modulator
TXQN, TXQP Differential Quadrature–phase TX baseband signals for the RF
modulator
VTX Supply voltage for the TX chain, which is also used for control of
the GSM 1800 TX/RX switch together with BAND_SEL and
VRX_1
VRX_1 Supply voltage for a part of the RX chain, which is also used for
control of the GSM 1800 TX/RX switch
Issue 1 07/99
NSE–5
System Module
Page 2 – 63