PT4316-SL 参数 Datasheet PDF下载

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Low Power 315/433 MHz OOK/ASK Superheterodyne

Receiver with SAW-based Oscillator

PT4316

AUTO GAIN CONTROL (AGC)

The AGC circuitry monitors the RSSI voltage level. As described above, when the RSSI voltage

reaches a first value corresponding to an RF input level of approximately -60dBm, the AGC reduces

the LNA gain by 20dB, thereby reducing the RSSI output by approximately 280mV. When the RSSI

voltage drops below a level corresponding to an RF input of approximately -66dBm, the AGC sets the

LNA back to high-gain mode.

The change of RSSI voltage versus RF input power is shown as the following figure. When the RSSI

level increases and then exceeds 1.68 V (RF input power rising), the AGC switches the LNA from

high-gain mode to low-gain mode. As RSSI level decreases back to 1.25V (RF input power falling), the

AGC switches the LNA from low-gain mode back to high-gain mode.

RSSI Curve w/wo AGC Function

1.90

RF Power from Low to High

1.75

1.60

1.45

1.30

1.15

1.00

-120

RF Power from High to Low

RSSI Curve without AGC

RSSI Voltage (V)

-100

-80

-60

-40

-20

RF Input Power (dBm)

RSSI vs. RF input power

PT4316 V1.6

-9-

August, 2007