Datasheet

MAX2029
Detailed Description
The MAX2029 can operate either as a downconverter
or an upconverter mixer. As a downconverter, the
MAX2029 yields a 6.5dB conversion loss, a 6.7dB noise
figure, and a +36.5dBm third-order input intercept point
(IIP3). The integrated baluns and matching circuitry
allow for 50Ω single-ended interfaces to the RF port and
the two LO ports. The RF port can be used as an input
for downconversion or an output for upconversion. A sin-
gle-pole, double-throw (SPDT) switch provides 50ns
switching time between the two LO inputs with 53dB 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 MAX2029’s inputs to a
-3dBm to +3dBm range. The IF port incorporates a dif-
ferential output for downconversion, which is ideal for
providing enhanced IIP2 performance. For upconver-
sion, the IF port is a differential input.
Specifications are guaranteed over broad frequency
ranges to allow for use in cellular band WCDMA,
cdmaOne™, cdma2000, and GSM 850/GSM 900 2.5G
EDGE base stations. The MAX2029 is specified to oper-
ate over an 815MHz to 1000MHz RF frequency range, a
570MHz to 900MHz LO frequency range, and a DC to
250MHz IF frequency range. Operation beyond these
ranges is possible; see the Typical Operating
Characteristics for additional details.
The MAX2029 is optimized for low-side LO injection archi-
tectures. However, the device can operate in high-side
LO injection applications with an extended LO range, but
performance degrades as f
LO
increases. See the Typical
Operating Characteristics for measurements taken with
f
LO
up to 1000MHz. For a pin-compatible device that has
been optimized for high-side LO injection, refer to the
MAX2031 data sheet.
RF Port and Balun
For using the MAX2029 as a downconverter, the RF
input is internally matched to 50Ω, requiring no external
matching components. A DC-blocking capacitor is
required because the input is internally DC shorted to
ground through the on-chip balun. The RF return loss is
typically better than 15dB over the entire 815MHz to
1000MHz RF frequency range. For upconverter opera-
tion, the RF port is a single-ended output similarly
matched to 50Ω.
LO Inputs, Buffer, and Balun
The MAX2029 is optimized for low-side LO injection
architectures with a 570MHz to 900MHz LO frequency
range. For a device with a 960MHz to 1180MHz LO fre-
quency range, refer to the MAX2031 data sheet. As an
added feature, the MAX2029 includes an internal LO
SPDT switch that can be used for frequency-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 nearly all GSM applications. If fre-
quency 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 be applied to V
CC
before digital logic is applied
to LOSEL (see the Absolute Maximum Ratings ). LO1
High-Linearity, 815MHz to 1000MHz Upconversion/
Downconversion Mixer with LO Buffer/Switch
12 ______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1, 6, 8, 14 V
CC
Power-Supply Connection. Bypass each V
CC
pin to GND with capacitors as shown in the Typical
Application Circuit.
2RFS i ng l e- E nd ed 50Ω RF Inp ut/O utp ut. Thi s p or t i s i nter nal l y m atched and D C shor ted to G N D thr oug h a b al un.
3 TAP Center Tap of the Internal RF Balun. Connect to ground.
4, 5, 10, 12,
13, 16, 17, 20
GND Ground. Connect to PCB ground plane for proper operation and improved pin-to-pin isolation.
7 LOBIAS Bias Resistor for Internal LO Buffer. Connect a 523Ω ±1% resistor from LOBIAS to the power supply.
9 LOSEL Local Oscillator Select. Logic-control input for selecting LO1 or LO2.
11 LO1 Local Oscillator Input 1. Drive LOSEL low to select LO1.
15 LO2 Local Oscillator Input 2. Drive LOSEL high to select LO2.
18, 19 IF-, IF+ Differential IF Input/Outputs
EP GND Exposed Ground Paddle. Solder the exposed paddle to the ground plane using multiple vias.
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