RF2364PCBA datasheet(4/10 Pages) RFMD

4 / 10 page

Preliminary

4-212

RF2364

Rev A4 010501

Application Notes

Power Down Pin Resistor

The Power Down pin (pin 3) of the RF2364 3 V Low Noise Amplifier should be maintained at 2.7V to 2.9 V for proper

operation. This voltage range ensures the correct bias current will be present at the Power Down pin of the device. How-

ever, an external series resistor may be used to allow various operating voltages at this pin (see R1 in Application Sche-

matics). The required value for this resistor may be roughly calculated by using the operating input voltage to the Power

Down pin, the desired voltage at the device, and the typical current consumption for the Power Down pin, along with

Ohms law.

For example, assume the design will supply 3.3V to the Power Down pin of the device, but the biasing circuitry internal to

the RF2364 requires 2.8 V, and the power down bias current is known to typically be 5.5 mA, then the required value from

R1 would be found from:

3.3V

2.8V

–

5.5mA

-----------------------------

90.9

Ω

RF2364PCBA Fiches technique(PDF) 4 Page - RF Micro Devices