RF2494 RF Micro Devices, RF2494 Datasheet - Page 3

• Manufacturer Part Number: RF2494
• Description: HIGH FREQUENCY LNA/MIXER
• Manufacturer: RF Micro Devices

Rev A0 010730
Preliminary
Pin
10
11
12
1
2
3
4
5
6
7
8
9
MIXOUT+
Function
MIXOUT-
RX EN
MIX IN
GND3
VCC1
VCC2
LO IN
VCC3
PD
NC
NC
Description
The power enable pin. When PD is >V
on. When PD is <300mV, then the part is turned off and typically draws
less than 1 A.
Supply voltage for bias circuits and logic control. A 10pF external
bypass capacitor is required and an additional 0.01 F is required if no
other low frequency bypass capacitors are nearby. The trace length
between the pin and the bypass capacitors should be minimized. The
ground side of the bypass capacitors should connect immediately to
ground plane.
Supply voltage for LO_Buffer. A 10pF bypass capacitor is required and
an additional 0.01 F is required if there is no other low frequency
bypass capacitor in the area. The trace length between the pin and the
bypass capacitors should be minimized. The ground side of the bypass
capacitors should connect immediately to ground plane.
The inverting open collector output of the mixer. This pin needs to be
externally biased and DC isolated from other parts of the circuit. This
output can drive a Balun, with MIXOUT+, to convert to unbalanced to
drive a SAW filter. The Balun can be either broadband (transformer) or
narrowband (discrete LC matching). Alternatively, MIXOUT+ may be
used alone to drive a SAW single-ended, with an RF choke (high Z at
IF) from VCC to MIXOUT-.
The non-inverting open collector output of the mixer. This pin needs to
be externally biased and DC isolated from other parts of the circuit.
This output can drive a Balun, with MIXOUT+, to convert to unbalanced
to drive a SAW filter. The Balun can be either broadband (transformer)
or narrowband (discrete LC matching). Alternatively, MIXOUT+ may be
used alone to drive a SAW single-ended, with an RF choke (high Z at
IF) from VCC to MIXOUT+.
LO input pin. This input needs a DC-blocking cap. External matching is
recommended to 50 .
This control pin allows the mixer output pins to be put into a high
impedance state. This allows the transmit signal path to share the
same IF filter as the receiver.
Supply voltage for mixer preamp.
Ground pin for mixer preamp. This lead inductance is intended to be
similar to VCC3 lead inductance.
Mixer RF Input port. This pin is NOT internally DC-blocked. An external
blocking capacitor must be provided if the pin is connected to a device
with DC present. A value of >22pF is recommended. To minimize the
noise figure it is recommended to have a bandpass filter before this
input. This will prevent the noise at the image frequency from being
converted to the IF.
Not connected.
Not connected.
CC
- 300mV, the part is biased
Interface Schematic
See pin 6.
See pin 4.
See pin 10.
See pin 10.
LO IN
MIX OUT+
MIX IN
RF2494
VCC2
VCC3
GND3
MIX OUT-
8-55
8