max2031etpt Maxim Integrated Products, Inc., max2031etpt Datasheet - Page 13

• Manufacturer Part Number: max2031etpt
• Description: Max2031 High-linearity, 815mhz To 1000mhz Upconversion/downconversion Mixer With Lo Buffer/switch
• Manufacturer: Maxim Integrated Products, Inc.

High-Linearity, 815MHz to 1000MHz Upconversion/
A two-stage internal LO buffer allows a wide input-
power range for the LO drive. All guaranteed specifica-
tions are for a -3dBm to +3dBm LO signal power. The
on-chip low-loss balun, along with an LO buffer, drives
the double-balanced mixer. All interfacing and match-
ing components from the LO inputs to the IF outputs
are integrated on-chip.
The core of the MAX2031 is a double-balanced, high-
performance passive mixer. Exceptional linearity is pro-
vided by the large LO swing from the on-chip LO buffer.
The MAX2031 mixer has a DC to 250MHz IF frequency
range. Note that these differential ports are ideal for pro-
viding enhanced IIP2 performance. Single-ended IF
applications require a 1:1 balun to transform the 50Ω dif-
ferential IF impedance to 50Ω single-ended. Including
the balun, the IF return loss is better than 15dB. The dif-
ferential IF is used as an input port for upconverter oper-
ation. The user can use a differential IF amplifier following
the mixer, but a DC block is required on both IF pins.
The RF and LO inputs are internally matched to 50Ω. No
matching components are required. As a downconvert-
er, the return loss at the RF port is typically better than
15dB over the entire input range (815MHz to 1000MHz),
and return loss at the LO ports are typically 15dB
(960MHz to 1180MHz). RF and LO inputs require only
DC-blocking capacitors for interfacing.
An optional L-C bandpass filter (BPF) can be installed at
the RF port to improve upconverter performance. See
the Typical Application Circuit and Typical Operating
Characteristics for upconverter operation with an L-C
BPF tuned for 810MHz RF frequency. Performance can
be optimized at other frequencies by choosing different
values for L1 and C4. Removing L1 and C4 altogether
results in a broader match, but performance degrades.
Contact factory for details.
The IF output impedance is 50Ω (differential). For eval-
uation, an external low-loss 1:1 (impedance ratio) balun
transforms this impedance to a 50Ω single-ended out-
put (see the Typical Application Circuit).
Bias current for the LO buffer is optimized by fine tun-
ing resistor R1. If reduced current is required at the
expense of performance, contact the factory for details.
If the ±1% bias resistor values are not readily available,
substitute standard ±5% values.
Downconversion Mixer with LO Buffer/Switch
Applications Information
______________________________________________________________________________________
Input and Output Matching
High-Linearity Mixer
Differential IF
Bias Resistor
A properly designed PC board is an essential part of
any RF/microwave circuit. Keep RF signal lines as short
as possible to reduce losses, radiation, and induc-
tance. For the best performance, route the ground-pin
traces directly to the exposed pad under the package.
The PC board exposed pad MUST be connected to the
ground plane of the PC board. It is suggested that mul-
tiple vias be used to connect this pad to the lower-level
ground planes. This method provides a good RF/ther-
mal conduction path for the device. Solder the exposed
pad on the bottom of the device package to the PC
board. The MAX2031 evaluation kit can be used as a
reference for board layout. Gerber files are available
upon request at www.maxim-ic.com.
Proper voltage-supply bypassing is essential for high-
frequency circuit stability. Bypass each V
the capacitors shown in the Typical Application Circuit.
See Table 1.
The exposed paddle (EP) of the MAX2031’s 20-pin thin
QFN-EP package provides a low-thermal-resistance
path to the die. It is important that the PC board on
which the MAX2031 is mounted be designed to con-
duct heat from the EP. In addition, provide the EP with
a low-inductance path to electrical ground. The EP
MUST be soldered to a ground plane on the PC board,
either directly or through an array of plated via holes.
Table 1. Typical Application Circuit
Component List
*C4 and L1 installed only when mixer is used as an upconverter.
**C5 installed only when mixer is used as a downconverter.
COMPONENT
C 1, C 2, C 7, C 8,
C 10, C 11, C12
C3, C6, C9
Exposed Pad RF/Thermal Considerations
C5**
C4*
L1*
U1
R1
T1
MAX2031 Maxim IC
VALUE
4.7nH
523Ω
82pF
10nF
6pF
2pF
1:1
Power-Supply Bypassing
Microwave capacitors (0603)
Microwave capacitors (0603)
Microwave capacitor (0603)
Microwave capacitor (0603)
Inductor (0603)
±1% resistor (0603)
IF balun M/A-COM: MABAES0029
Layout Considerations
DESCRIPTION
CC
pin with
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