MGCT03
Transmit Circuit for TDMA/AMPS
Features
•
•
•
•
•
Dual RF Ports for 900MHz and 1900MHz
AGC Amplifier with 90dB of Variable Gain, Fully
Compensated for Temperature
On-chip Active Filter. Removes the
Requirement for External IF SAW Filter
High Power 900MHz and 1900MHz Output
Stages
Quadrature Modulator
DS5418
ISSUE 1.0
December 2000
Ordering Information
MGCT03/KG/QP1S
MGCT03/KG/QP1T
Applications
•
Transmit Modulator and Up-converter in TDMA/
AMPS Mobile Phones
The MGCT03 circuit is designed for use in dual
band, dual mode cellular 900MHz/PCS1900MHz
mobile phones. It can be used for TDMA/AMPS. The
MGCT03 is compatible with baseband and mixed
signal interface circuits from Zarlink Semiconductor
and other manufacturers.
System costs have been kept to a minimum by
removing the requirement for an additional SAW filter
in the transmit IF path. The AGC has been split
between RF and IF sections to reduce noise and a
low pass filter has been included before the IF
variable gain amplifier to remove spurious products
produced in the modulator.
For CDMA systems the MGCT04 is recommended.
Absolute Maximum Ratings
Supply voltage (V
CC
)
4V
Control input voltage
-0.6V to VCC + 0.6V
-55˚C to +125˚C
Storage temperature, T
STG
Operating temperature
-40˚C to 100˚C
150˚C
Max Junction Temperature (T
J
)
CP2
1
CP1
27
CP0
28
LO 2GHz
23
UHF
OSCILLATOR
INPUT SELECT
LO 1GHz
25
CONTROL LOGIC
1900 MHz
OUTPUT DRIVER
Q IN
Q IN
17
18
7
6
POWER CONTROL
RF190
RF190
RFDEG1
RFDEG2
RF900
RF900
÷
2/4 AND
20
19
PHASE
SHIFT
IF VGA
ALL PASS
PHASE
SHIFT
NETWORK
RF VGA
3
4
9
8
SSB MIXER
VGA CONTROL
900 MHz
OUTPUT DRIVER
I IN
I IN
OSC
BUFFER
V
REF
12
BIAS
BUFFER
11
2
VHF OSC IN
VHF OSC BIAS
AGC
Figure 1 - MGCT03 Block Diagram
1
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
