SIGMA BENEFON TDP-52-SN3 - Manual (Page 75)

27.1.1999
4Z0700GB.__2 41
Product: TDP-52-SN3 (Sigma Gold) /
Transmitter
OY0725Transmitter
5.3.9 General
5.3.10 Function Description
The transmitter unit is comprised of three amplifier stages and two attenuator
stages. The pre-amplifier Q600 and power module I620 form the transmitter ampli-
fier chain. The attenuators surrounding the pre-amplifier are included to enhance the
electric separation between the TX synthesizer and the transmitter. C650 enhances
power module efficiency.
The operational amplifier I610 and transistors Q610 and Q611 serve as a power reg-
ulator circuit, which adjusts the power level so that the voltage from the transmitter
power detector (D610) and the control voltage TXPWR from the audio/processor
unit are equal. The power-module power-control voltage must not exceed 4V.
I601 serves as voltage regulator for the power controller and also as the ON/OFF
switch for RF output power.
When the phone is connected to an external voltage supply, the audio/processor unit
raises the transmitter power by approx 1.0 dB using the TXPWR control.
5.3.11 Control- and Output-Signals
Operating voltage 5,7...8,0 VDC
Current consumption mid power max. 1.0 A
low power max. 0.45 A
Input level from the synthesizer +6 dBm
Output level to the duplex filter mid power 33 dBm (2.0W)
low power 24.7 dBm (0.3W)
Frequency range 453,000...457,475 MHz
VBAT
Transmitter operating voltage from the
battery-pack (fused)
TXBIAS Power ON/OFF control
TXPWR
Power level control signal from the D/A
converter
0...5V
TXINJ RF signal from the TX synthesizer +6dBm
TXDUPLEX Transmitter output to the duplex filter