MAX19998ETP+T Maxim Integrated Products, MAX19998ETP+T Datasheet - Page 26

• Manufacturer Part Number: MAX19998ETP+T
• Description: RF Mixer SiGe High-Linearity 2300MHz to 4500MHz D
• Manufacturer: Maxim Integrated Products

Specifications of MAX19998ETP+T

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Short LEXT to ground using a 0I resistor. For applica-
tions requiring improved RF-to-IF and LO-to-IF isolation,
L3 can be changed to optimize performance (see the
Typical Operating Characteristics). However, the load
impedance presented to the mixer must be such that any
capacitances from IF- and IF+ to ground do not exceed
several picofarads to ensure stable operating conditions.
Since approximately 120mA flows through LEXT, it is
important to use a low-DCR wire-wound inductor.
A properly designed PCB is an essential part of any RF/
microwave circuit. Keep RF signal lines as short as pos-
sible to reduce losses, radiation, and inductance. The
load impedance presented to the mixer must be such
that any capacitance from both IF- and IF+ to ground
SiGe, High-Linearity, 2300MHz to 4000MHz
Downconversion Mixer with LO Buffer
*Use larger value inductors and a TC4-1W-7A 4:1 balun for IF frequencies below 200MHz.
Table 1. Component Values
26
C2, C6, C8, C11
DESIGNATION
_____________________________________________________________________________________
C13, C14
C3, C9
L1, L2
C10
C15
C16
C1
U1
R1
R2
R3
L3
T1
QTY
1
4
0
1
2
1
1
2
1
1
1
1
1
1
Layout Considerations
8.2pF microwave capacitor (0402). Use for RF
frequencies ranging from 3000MHz to 4000MHz.
3.3nH microwave inductor (0402). Use for RF
frequencies ranging from 2300MHz to 2900MHz.
0.01FF microwave capacitors (0402)
Not installed, capacitors
2pF microwave capacitor (0402)
1000pF microwave capacitors (0402)
82pF microwave capacitor (0402)
Not installed for RF frequencies ranging from
3000MHz to 4000MHz
0.3pF microwave capacitor (0402). Use for RF
frequencies ranging from 2300MHz to 2900MHz.
390nH wire-wound high-Q inductors* (0805)
4.7nH wire-wound high-Q inductor (0603)
698I Q1% resistor (0402). Use for V
applications.
845I Q1% resistor (0402). Use for V
applications.
604I Q1% resistor (0402). Use for V
applications.
1.1kI Q1% resistor (0402). Use for V
applications.
0I resistor (1206)
4:1 IF balun TC4-1W-17*
MAX19998 IC (20 Thin QFN-EP)
LEXT Inductor
DESCRIPTION
does not exceed several picofarads. For the best per-
formance, route the ground pin traces directly to the
exposed pad under the package. The PCB exposed pad
MUST be connected to the ground plane of the PCB. 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 PCB. The MAX19998 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
capacitors shown in the Typical Application Circuit and
see Table 1 for component values.
CC
CC
CC
CC
= 5.0V
= 3.3V
= 5.0V
= 3.3V
Murata Electronics North America, Inc.
Coilcraft, Inc.
Murata Electronics North America, Inc.
—
Murata Electronics North America, Inc.
Murata Electronics North America, Inc.
Murata Electronics North America, Inc.
—
Murata Electronics North America, Inc.
Coilcraft, Inc.
Coilcraft, Inc.
Digi-Key Corp.
Digi-Key Corp.
Digi-Key Corp.
Mini-Circuits
Maxim Integrated Products, Inc.
COMPONENT SUPPLIER
Power-Supply Bypassing
CC
pin with the