MAX2041
High-Linearity, 1700MHz to 3000MHz Upconversion/
Downconversion Mixer with LO Buffer/Switch
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Detailed Description
The MAX2041 can operate either as a downconverter
or an upconverter mixer that provides 7.2dB of conver-
sion loss with a typical 7.4dB noise figure. IIP3 is
+33.5dBm for both upconversion and downconversion
operation. The integrated baluns and matching circuitry
allow for 50Ω single-ended interfaces to the RF port
and two LO ports. The RF port can be used as an input
for downconversion or an output for upconversion. A
single-pole, double-throw (SPDT) switch provides 50ns
switching time between the two LO inputs with 43dB of
LO-to-LO isolation. Furthermore, the integrated LO
buffer provides a high drive level to the mixer core,
reducing the LO drive required at the MAX2041’s
inputs to a range of -3dBm to +3dBm. The IF port incor-
porates a differential output for downconversion, which
is ideal for providing enhanced IIP2 performance. For
upconversion, the IF port is a differential input.
Specifications are guaranteed over broad frequency
ranges to allow for use in UMTS, cdma2000, 2G/2.5G/3G
DCS 1800, PCS 1900, and WiMAX base stations. The
MAX2041 is specified to operate over an RF frequency
range of 1700MHz to 3000MHz, an LO frequency range
of 1900MHz to 3000MHz, and an IF frequency range of
DC to 350MHz. Operation beyond these ranges is pos-
sible; see the Typical Operating Characteristics for
additional details.
This device can operate equally well in low-side LO injec-
tion applications as long as the LO frequency range is
between 1900MHz and 3000MHz. If an LO frequency
range below 1900MHz is desired, refer to the MAX2039.
RF Port and Balun
For using the MAX2041 as a downconverter, the RF input
is internally matched to 50Ω, requiring no external match-
ing components. A DC-blocking capacitor is required
since the input is internally DC shorted to ground through
the on-chip balun. The RF return loss is typically better
than 17dB over a 1400MHz to 3000MHz frequency range.
For upconverter operation, the RF port is a single-ended
output similarly matched to 50Ω.
LO Inputs, Buffer, and Balun
The MAX2041 can be used for either high-side or low-
side injection applications with a 1900MHz to 3000MHz
LO frequency range. For a device with a 1500MHz to
2000MHz LO frequency range, refer to the MAX2039
data sheet. As an added feature, the MAX2041 includes
an internal LO SPDT switch that can be used for frequen-
cy-hopping applications. The switch selects one of the
two single-ended LO ports, allowing the external oscillator
to settle on a particular frequency before it is switched in.
LO switching time is typically less than 50ns, which is
more than adequate for virtually all GSM applications. If
frequency hopping is not employed, set the switch to
either of the LO inputs. The switch is controlled by a
digital input (LOSEL): logic-high selects LO2, logic-low
selects LO1. To avoid damage to the part, voltage MUST
Pin Description
