HFA3761 Datasheet, PDF (1/9 Pages) Intersil Corporation – 400MHz AGC and Quadrature IF Demodulator

TM
Data Sheet
HFA3761
July 1999 File Number 4236.4
400MHz AGC and Quadrature IF
Demodulator
The HFA3761 is a highly integrated
baseband converter for quadrature
demodulation applications. The
HFA3761 400MHz AGC and
quadrature IF demodulator is one of the
seven chips in the PRISM® full duplex chip set (see Typical
Application Diagram). It features all the necessary blocks for
baseband demodulation of I and Q signals. It has a two
stage integrated AGC IF amplifier with 82dB of voltage gain
and 76dB of gain control range. Baseband antialiasing and
shaping filters are integrated in the design. Four filter
bandwidths are programmable via a two bit digital control
interface. In addition, these filters are continuously tunable
over a ±20% frequency range via one external resistor. To
achieve broadband operation, the Local Oscillator
frequency input is required to be twice the desired
frequency of demodulation. A selectable buffered divide by
2 LO output and a stable reference voltage are provided for
convenience of the user. The device is housed in a thin 80
lead TQFP package well suited for PCMCIA board
applications.
Ordering Information
TEMP.
PART NUMBER RANGE (^oC) PACKAGE
HFA3761IN
-40 to 85 80 Ld TQFP
PKG. NO.
Q80.14x14
Simplified Block Diagram
Features
• Integrates all IF and AGC Receive Functions
• Broad Frequency Range . . . . . . . . . . 10MHz to 400MHz
• I/Q Amplitude and Phase Balance . . . . 0.2dB, 2 Degrees
• 5th Order Programmable
Low Pass Filter . . . . . . . . . . . . . . . . . 2.2MHz to 17.6MHz
• 400MHz AGC Gain Strip . . . . . . . . . . . . . . . . . . . . . 82dB
• AGC Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75dB
• Low LO Drive Level . . . . . . . . . . . . . . . . . . . . . . . -15dBm
• Fast AGC Switching . . . . . . . . . . . . . . . . . . . . . . . . . . 1µs
• Power Management/Standby Mode
• Single Supply 2.7V to 5.5V Operation
Applications
• Wireless Local Loop
• Wireless Local Area Networks
• PCMCIA Wireless Transceivers
• ISM Systems
• CDMA Radios
• PCS/Wireless PBX
AGC_SEL
AGC1_IN
AGC1_V_AGC
AGC2_V_AGC
DEMOD_LO_IN
DEMOD_LO_OUT
LO_GND
I
÷2 0^o/90^o
Q
2V
REF
LPF_RXI_OUT
LPF_RXQ _OUT
4-1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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