Document
www.DataSheet4U.com
Features
• • • •
Gain Control in 20-dB Steps Very Low I/Q Amplitude and Phase Errors High Input P1dB Small and Optimized Package for High Reliability and Performance
Applications
• Infrastructure Digital Communication Systems • GSM/Cellular Transceivers • ISM Band Transceivers
Benefits
• Fully Integrated Device with Reduced External Component Count
65 - 300 MHz SiGe IF Receiver/ Demodulator ATR0797
Electrostatic sensitive device. Observe precautions for handling.
Description
The ATR0797 is a multi-purpose demodulator RFIC. The silicon monolithic integrated circuit is designed with Atmel’s advanced SiGe technology. This demodulator is capable of both quadrature demodulation or direct IF output. Features include switchable gain control on a frequency range from 65 MHz to 300 MHz. The device performs a very low amplitude as well as phase error and allows high input P1dB. The ATR0797 targets a variety of system applications for communications including 3G wireless. Figure 1. Block Diagram
GC1
5
GC2
4 2 1
BBIP BBIN
IFP IFN
8 9
ϕ
16 15 13 12
BBQP BBQN
LOP LON
Rev. 4665D–SIGE–08/04
DataSheet 4 U .com
www.DataSheet4U.com
Pin Configuration
Figure 2. Pinning
BBIN BBIP VCC GC2 GC1 GND VCC IFP 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 BBQP BBQN VCC LOP LON GND VCC IFN
Pin Description
Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Symbol BBIN BBIP VCC GC2 GC1 GND VCC IFP IFN VCC GND LON LOP VCC BBQN BBQP Function Baseband I-axis negative output, self biasing Baseband I-axis positive output, self biasing 5 V power supply Gain control input, stage 2, 5 V CMOS levels Gain control input, stage 1, 5 V CMOS levels Ground 5 V power supply IF positive input, self biasing, AC-coupled IF negative input, self biasing, AC-coupled 5 V power supply Ground Local oscillator, negative input, self biasing, AC-coupled Local oscillator, positive input, self biasing, AC-coupled 5 V power supply Baseband Q-axis negative output, self biasing Baseband Q-axis positive output, self biasing
2
ATR0797
4665D–SIGE–08/04
DataSheet 4 U .com
www.DataSheet4U.com
ATR0797
Product Description
Atmel’s ATR0797 is a variable gain I-Q demodulator designed for use in receiver IF sections, that are typically existing in superheterodyne RF architectures. The ATR0797 has two gain stages that are independent of each other. These gain stages are broadband differential amplifiers each with a digital control pin to set the gain. Since the amplifiers have approximately the same gain, setting GC1 high and GC2 low results in approximately the same gain as setting GC1 low and GC2 high. Former setting offers better noise figures. The IF input is a differential input that has internal bias circuitry to set the common mode voltage. The use of blocking capacitors to facilitate AC coupling is highly recommended to avoid changing the common mode voltage. Either input may be driven single ended if the other input is connected to ground through an AC short such as a 1000 pF capacitor.