MAX2021ETX+ Maxim Integrated Products, MAX2021ETX+ Datasheet - Page 11

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

Specifications of MAX2021ETX+

• Maximum Operating Temperature: + 85 C
• Maximum Power Dissipation: 1355 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: 271 mA
• Package / Case: QFN-36
• Output Power: 0.7 dBm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

R2, and R3. Tables 1 and 2 outline the performance
trade-offs that can be expected for various combina-
tions of these bias resistors. As noted within the tables,
the performance trade-offs may be more pronounced
for different operating frequencies. Contact the factory
for additional details.
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 paddle MUST be connected to
the ground plane of the PC board. It is suggested that
multiple vias be used to connect this pad to the lower-
level ground planes. This method provides a good
RF/thermal conduction path for the device. Solder the
exposed pad on the bottom of the device package to
the PC board. The MAX2021 evaluation kit can be used
as a reference for board layout. Gerber files are avail-
able upon request at www.maxim-ic.com.
Proper voltage-supply bypassing is essential for high-
frequency circuit stability. Bypass all VCC_ pins with
Table 1. Typical Performance Trade-Offs as a Function of Current Draw—Modulator Mode
Note: V
High-Dynamic-Range, Direct Up-/Downconversion
LO FREQ
(MHz)
1000
800
900
CC
= 5V, P
750MHz to 1200MHz Quadrature Mod/Demod
RF FREQ
1001.8
(MHz)
801.8
901.8
LO
______________________________________________________________________________________
= 0dBm, T
Power-Supply Bypassing
420
453
499
549
650
420
453
499
549
650
420
453
499
549
650
(Ω Ω Ω Ω )
R1
Layout Considerations
A
= +25°C, I/Q voltage levels = 1.4V
1000
1000
1000
620
665
698
806
620
665
698
806
620
665
698
806
(Ω Ω Ω Ω )
R2
550
550
550
330
360
402
464
330
360
402
464
330
360
402
464
(Ω Ω Ω Ω )
R3
P-P
(mA)
33pF and 0.1µF capacitors placed as close to the pins
as possible. The smallest capacitor should be placed
closest to the device.
To achieve optimum performance, use good voltage-
supply layout techniques. The MAX2021 has several RF
processing stages that use the various VCC_ pins, and
while they have on-chip decoupling, off-chip interaction
between them may degrade gain, linearity, carrier sup-
pression, and output power-control range. Excessive
coupling between stages may degrade stability.
The EP of the MAX2021’s 36-pin thin QFN-EP package
provides a low thermal-resistance path to the die. It is
important that the PC board on which the IC is mounted
be designed to conduct heat from this contact. In addi-
tion, the EP provides a low-inductance RF ground path
for the device.
The exposed paddle (EP) MUST be soldered to a
ground plane on the PC board either directly or through
an array of plated via holes. An array of 9 vias, in a 3 x
3 array, is suggested. Soldering the pad to ground is
critical for efficient heat transfer. Use a solid ground
plane wherever possible.
271
253
229
205
173
271
253
229
205
173
271
253
229
205
173
I
CC
differential.
Exposed Pad RF/Thermal Considerations
(dBm)
OIP3
19.6
21.9
18.9
15.7
13.6
20.7
21.6
20.6
19.0
14.9
22.4
22.2
19.9
17.6
14.6
LO LEAK
(dBm)
-32.1
-32.7
-33.7
-34.4
-34.2
-31.4
-31.6
-31.8
-31.9
-30.5
-32.8
-33.2
-33.8
-34.8
-33.9
IMAGE REJ
(dBc)
23.9
34.0
30.0
23.7
23.3
43.4
42.4
42.7
40.3
25.0
39.3
39.1
43.5
40.5
36.8
(dBm)
OIP2
50.5
51.0
52.6
46.0
32.3
54.0
55.4
59.8
50.7
34.6
55.5
56.3
55.0
51.4
32.8
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