RF2444 Ver la hoja de datos (PDF) - RF Micro Devices

Número de pieza

componentes Descripción

Fabricante

RF2444

HIGH FREQUENCY LNA/MIXER

RF Micro Devices 

RF2444

Pin Function Description

Interface Schematic

1

GAIN SEL LNA gain control. When GAIN SEL is >VCC- 300mV, LNA gain is at 10 See pin 16.

dB. When GAIN SEL is <300mV, the LNA gain is -6dB.

2

LNA IN This pin is NOT internally DC blocked. An external blocking capacitor See pin 16.

must be provided if the pin is connected to a device with DC present. If

a blocking capacitor is required, a value of 2pF is recommended.

3

PD

The power enable pin. When PD is >VCC- 300mV, the part is biased

on. When PD is <300mV, then the part is turned off and typically draws

less than 1µA.

4

VCC1

Supply voltage for bias circuits and logic control. A 10pF external

bypass capacitor is required and an additional 0.01µF 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.

5

VCC2

Supply voltage for LO_Buffer. A 10pF bypass capacitor is required and See pin 8.

an additional 0.01µF 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.

6

MIXOUT- 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

MIX OUT+ MIX OUT-

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

8

IF) from VCC to MIXOUT-.

7

MIXOUT+ The non-inverting open collector output of the mixer. This pin needs to See pin 6.

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+.

8

LO IN

LO input pin. This input needs a DC blocking cap. External matching is

VCC2

recommended to 50Ω.

LO IN

9

RX EN

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.

10

VCC3

Supply voltage for mixer preamp.

See pin 12.

11

GND3

Ground pin for mixer preamp. This lead inductance should be kept

See pin 12.

small.

12

MIX IN

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.

VCC3

MIX IN

8-56

GND3

Rev A3 010717

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