Data Sheet

ADL5910

Rev. 0 | Page 13 of 22

VOLTAGE

Figure 17 shows the typical relationship between the voltage

on the VIN− pin and the RF input power on the RFIN pin This

data is also presented in Table 5.

0.001

0.01

0.1

1

10

–40 –35 –30 –25 –20 –15 –10

–5

0

5

10

15

20

0.01GHz

0.03GHz

0.1GHz

0.9GHz

1.9GHz

2.6GHz

3.6GHz

5.8GHz

Use Figure 17 and Table 5 to set the threshold voltage on the

VIN− pin. However, because the relationship between the

threshold voltage on VIN− and the resulting RF threshold

power varies from device to device, there is an error level of up

to ±2.5 dB. For example, if the voltage on VIN− is set to cause

the circuit to trip when the input power exceeds 0 dBm at 900 MHz

device to device by ±2.5 dB at frequencies at or above 100 MHz

and +2.5 dB to −5.5 dB for frequencies below 100 MHz. In Table 5,

no recommended voltages are provided for input power levels

less than −25 dBm from 10 MHz to 3.5 GHz and less than −20

dBm at 5.8 GHz because of the increased temperature drift at

these input power levels. Likewise, from 10 MHz to 3.5 GHz, no

recommended voltages are provided for input power levels

more than 13 dBm because at this power level the response of

the ADL5910 starts to become more nonlinear.

To set the threshold detect level more precisely, there are two

calibration options. A single-point calibration is accomplished

easily by applying the threshold trip power level and then

adjusting VIN− until Q trips high. Initially, set VIN− to a high

level such as 2 V, and then assert RST high and back to low to

ensure that Q is low. Next, apply the RF input threshold power

level to RFIN. Then, reduce the voltage on VIN− until the Q

output goes high. Use this resulting voltage to set the threshold

level when the equipment is in operation.