725MHz to 1085MHz. An internal LO switch allows for
switching between two single-ended LO ports; this is
useful for fast frequency changes/frequency hopping.
LO switching time is typically less than 250ns. The
switch is controlled by a digital input (LOSEL) that
when high, selects LO1 and when low, selects LO2.
Internal LO buffers allow for a wide power range on the
LO ports. The LO signal power can vary from -5dBm to
+5dBm. LO1 and LO2 are internally matched to 50Ω,
so only a 33pF DC-blocking capacitor is required at
each LO port.
IF Outputs
This mixer has an IF frequency range of 70MHz to
170MHz. The differential IF output ports require external
pullup inductors to VCC to resonate out the differential
on-chip capacitance of 1.8pF. See the Typical Appli-
cation Circuit for recommended component values for an
IF optimized for 70MHz to 100MHz. Higher IF frequen-
cies can be optimized by reducing the values of L1 and
L2.
Removing the ground plane from underneath L1 and L2
reduces parasitic capacitive loading and improves
VSWR.
Bias Circuitry
Connect a bias resistor from RFBIAS to ground to set the
mixer bias current. A nominal resistor value of 249Ωsets
an input IP3 of +26.8dBm and supply current of 168mA.
Applications Information
Layout Considerations
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 best performance, route the ground pin
traces directly to the exposed paddle underneath the
package. Solder the exposed pad on the bottom of the
device package evenly to the board ground plane to
provide a heat transfer path along with RF grounding. If
the PC board ground plane is not immediately available
on the top metal layer, provide multiple vias between
the exposed paddle connection and the PC board
ground plane.
Power-Supply Bypassing
Proper voltage supply bypassing is essential for high-
frequency circuit stability. Bypass each VCC pin with a
0.1µF capacitor. Bypass TAP by placing a 33pF (C2) to
ground within 100 mils of the TAP pin.
Chip Information
TRANSISTOR COUNT: 179
PROCESS: BiCMOS
MAX9982
825MHz to 915MHz, SiGe High-Linearity
Active Mixer
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