MAX2022ETX+ Maxim Integrated Products, MAX2022ETX+ Datasheet - Page 10

• Manufacturer Part Number: MAX2022ETX+
• Description: Modulator / Demodulator IC MOD 1500MHZ TO 2500MHZ
• Manufacturer: Maxim Integrated Products

Specifications of MAX2022ETX+

• Maximum Operating Temperature: + 85 C
• Maximum Power Dissipation: 1460 mW
• Minimum Operating Temperature: - 40 C
• Modulation Type: Quadrature
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 4.75 V to 5.25 V
• Supply Current: 292 mA
• Package / Case: QFN-36
• Output Power: - 24 dBm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

up to 2V
The wide input bandwidth allows for direct interface with
the baseband DACs. No active buffer circuitry between
the baseband DAC and the MAX2022 is required.
The I and Q signals directly modulate the 0° and 90°
LO signals and are upconverted to the RF frequency.
The outputs of the I and Q mixers are combined
through a balun to a singled-ended RF output.
The LO input of the MAX2022 requires a single-ended
drive at a 1500MHz to 2500MHz frequency. It is inter-
nally matched to 50Ω. An integrated balun converts the
singled-ended input signal to a differential signal at the
LO buffer differential input. An external DC-blocking
capacitor is the only external part required at this inter-
face. The LO input power should be within the -3dBm
to +3dBm range.
The COMP pin is used to provide additional lowpass fil-
tering to the bias circuit noise. An external capacitor
can be used from the COMP pin to ground to reduce
the close-in noise of the modulator. For UMTS, connect-
ing a 22pF capacitor from the COMP pin to ground is
recommended to filter out noise and frequency offsets
High-Dynamic-Range, Direct Upconversion
1500MHz to 2500MHz Quadrature Modulator
Figure 1. MAX5895 DAC Interfaced with MAX2022
10
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P-P
differential (common-mode input equals 0V).
Applications Information
BBQ
BBI
DUAL 16-BIT INTERP DAC
OFFSET ADJUST
I/Q GAIN AND
MAX5895
LO Input Drive
COMP Pin
FREQ
FREQ
50Ω
50Ω
50Ω
50Ω
LO
above 3.5MHz. For GSM, connecting a 1nF capacitor
from COMP to ground is recommended for filtering out
noise and frequency offsets above 600kHz.
The MAX2022 I and Q baseband inputs should be dri-
ven differentially for best performance. The baseband
inputs have a 50Ω differential input impedance. The
optimum source impedance for the I and Q inputs is
100Ω differential. This source impedance will achieve
the optimal signal transfer to the I and Q inputs, and the
optimum output RF impedance match. The MAX2022
can accept input power levels of up to +12dBm on the I
and Q inputs. Operation with complex waveforms, such
as CDMA or WCDMA carriers, utilize input power levels
that are far lower. This lower power operation is made
necessary by the high peak-to-average ratios of these
complex waveforms. The peak signals must be kept
below the compression level of the MAX2022. The input
common-mode voltage should be confined to the -2V to
+1.5V DC range.
The MAX2022 is designed to interface directly with
Maxim high-speed DACs. This generates an ideal total
transmitter lineup, with minimal ancillary circuit elements.
Such DACs include the MAX5875 series of dual DACs,
and the MAX5895 dual interpolating DAC. These DACs
have ground-referenced differential current outputs.
Typical termination of each DAC output into a 50Ω load
50Ω
50Ω
50Ω
0°
RF MODULATOR
MAX2022
90°
∑
Baseband I/Q Input Drive