MAX2021ETX+T Maxim Integrated Products, MAX2021ETX+T Datasheet - Page 8

• Manufacturer Part Number: MAX2021ETX+T
• Description: Modulator / Demodulator IC MOD/DEMOD irect Up-/Downconver
• Manufacturer: Maxim Integrated Products

Specifications of MAX2021ETX+T

• Package / Case: QFN-36
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

High-Dynamic-Range, Direct Up-/Downconversion
750MHz to 1200MHz Quadrature Mod/Demod
The MAX2021 is designed for upconverting differential
in-phase (I) and quadrature (Q) inputs from baseband
to a 750MHz to 1200MHz RF frequency range. The
device can also be used as a demodulator, downcon-
verting an RF input signal directly to baseband.
Applications include RFID handheld and portal readers,
as well as single and multicarrier GSM/EDGE,
cdma2000, WCDMA, and iDEN base stations. Direct
conversion architectures are advantageous since they
significantly reduce transmitter or receiver cost, part
count, and power consumption as compared to tradition-
al IF-based double conversion systems.
The MAX2021 integrates internal baluns, an LO buffer, a
phase splitter, two LO driver amplifiers, two matched
double-balanced passive mixers, and a wideband
quadrature combiner. The MAX2021’s high-linearity mix-
ers, in conjunction with the part’s precise in-phase and
quadrature channel matching, enable the device to pos-
sess excellent dynamic range, ACLR, 1dB compression
8
1, 5, 9–12, 14, 16–19, 22,
24, 27–30, 32, 34, 35, 36
_______________________________________________________________________________________
PIN
EP
13
15
20
21
23
25
26
31
33
2
3
4
6
7
8
Detailed Description
RBIASLO3 3rd LO Amplifier Bias. Connect a 332Ω resistor to ground.
RBIASLO1 1st LO Input Buffer Amplifier Bias. Connect a 432Ω resistor to ground.
RBIASLO2 2nd LO Amplifier Bias. Connect a 619Ω resistor to ground.
VCCLOQ2
VCCLOQ1
VCCLOI1
VCCLOI2
VCCLOA
NAME
BBQ+
BBQ-
BBI+
GND
GND
N.C.
BBI-
LO
RF
Ground
LO Input Buffer Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1µF
capacitors as close to the pin as possible.
Local Oscillator Input. 50Ω input impedance.
No Connection. Leave unconnected.
I-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1µF
capacitors as close to the pin as possible.
I-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1µF
capacitors as close to the pin as possible.
Baseband In-Phase Noninverting Port
Baseband In-Phase Inverting Port
RF Port
Baseband Quadrature Inverting Port
Baseband Quadrature Noninverting Port
Q-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1µF
capacitors as close to the pin as possible.
Q-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1µF
capacitors as close to the pin as possible.
Exposed Ground Paddle. The exposed paddle MUST be soldered to the ground plane
using multiple vias.
point, and LO and sideband suppression characteris-
tics. These features make the MAX2021 ideal for four-
carrier WCDMA operation.
The MAX2021 requires a single-ended LO input, with a
nominal power of 0dBm. An internal low-loss balun at
the LO input converts the single-ended LO signal to a
differential signal at the LO buffer input. In addition, the
internal balun matches the buffer’s input impedance to
50Ω over the entire band of operation.
The output of the LO buffer goes through a phase split-
ter, which generates a second LO signal that is shifted
by 90° with respect to the original. The 0° and 90° LO
signals drive the I and Q mixers, respectively.
Following the phase splitter, the 0° and 90° LO signals
are each amplified by a two-stage amplifier to drive the
I and Q mixers. The amplifier boosts the level of the LO
FUNCTION
LO Input Balun, LO Buffer, and
Pin Description
Phase Splitter
LO Driver