MGCT03 Datasheet, PDF (1/11 Pages) Zarlink Semiconductor Inc – Transmit Circuit for TDMA/AMPS

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
Applications
• Transmit Modulator and Up-converter in TDMA/
AMPS Mobile Phones
Absolute Maximum Ratings
Supply voltage (VCC)
4V
Control input voltage
-0.6V to VCC + 0.6V
Storage temperature, T_STG
Operating temperature
-55˚C to +125˚C
-40˚C to 100˚C
Max Junction Temperature (T_J)
150˚C
DS5418
ISSUE 1.0
Ordering Information
MGCT03/KG/QP1S
MGCT03/KG/QP1T
December 2000
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.
Q IN ¹⁷
Q IN ¹⁸
I IN ²⁰
I IN ¹⁹
CP2
1
CP1
27
CP0
28
÷2/4 AND
PHASE
SHIFT
CONTROL LOGIC
POWER CONTROL
IF VGA
LO 2GHz
23
UHF
OSCILLATOR
INPUT SELECT
ALL PASS
PHASE
SHIFT
NETWORK
SSB MIXER
OSC
BUFFER
VREF
12
VHF OSC IN
BIAS
BUFFER ¹¹
VHF OSC BIAS
VGA CONTROL
2
AGC
LO 1GHz
25
RF VGA
1900 MHz
OUTPUT DRIVER
900 MHz
OUTPUT DRIVER
7 _RF190
6 _RF190
3 _RFDEG1
4 _RFDEG2
9 _RF900
8 _RF900
Figure 1 - MGCT03 Block Diagram
1