LMX2604 Datasheet, PDF (1/15 Pages) National Semiconductor (TI) – Triple-band VCO for GSM900/DCS1800/PCS1900

OBSOLETE
LMX2604
www.ti.com
SNOSA61B – JANUARY 2004 – REVISED APRIL 2013
LMX2604 Triple-band VCO for GSM900/DCS1800/PCS1900
Check for Samples: LMX2604
FEATURES
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•2 On-Chip Triple-Band RF VCOs
– GSM: 880 MHz to 915 MHz
– DCS: 1710 MHz to 1785 MHz
– PCS: 1850 MHz to 1910 MHz
• On-Chip Tank Circuit
• Low Phase Noise
– -167 dBc/Hz @ 20 MHz Offset in GSM Band
– -163 dBc/Hz @ 20 MHz Offset in DCS Band
– -162 dBc/Hz @ 20 MHz Offset in PCS Band
• High Output Power
– +6 dBm in GSM Mode
– +6 dBm in DCS and PCS Mode
• Low Current Consumption
– 18 mA in GSM Mode
– 15 mA in DCS and PCS Mode
• +2.6 V to +3.0 V Supply Voltage
• 0.25 µm RF CMOS Process
• Small 20-Pin 4x4 WQFN Package
APPLICATIONS
• Transmit VCO for GSM, DCS, and PCS
• Closed Loop Modulation Systems
DESCRIPTION
The LMX2604 is a fully integrated VCO (Voltage-
Controlled Oscillator) IC designed for
GSM900/DCS1800/PCS1900 triple-band application.
The IC is ideal for use in the transmitter modulation
loop by providing extremely small form factor and low
phase noise. The IC has two VCOs, one for GSM
and a second for DCS/PCS. The IC has two separate
buffer amplifiers to drive an external high power
amplifier, one for GSM900 band and the other one for
DCS1800/PCS1900 bands. The IC also has a
differential buffer amplifier to drive a mixer for the
offset PLL.
The resonant circuits of the VCOs are fully integrated
in the chip to ease the application of the IC. The high
quality factor of the embedded tank circuit achieves
very low phase noise characteristics at the VCO
output. The only required external components are a
couple of supply bypass capacitors and matching
components.
A control pin for controlling the oscillation frequency
is shared by the two VCOs.
The LMX2604 IC is provided in a 20-pin 4x4 WQFN
(Leadless Leadframe package).
FUNCTIONAL BLOCK DIAGRAM
16
CPin
GSM VCO
12
GSMout
DCS/PCS VCO
13
DCSPCSout
1
CE
BSW ⁵
Band
Control
3
MIXout
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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