MAX2014
50MHz to 1000MHz, 75dB Logarithmic
Detector/Controller
10
variable-gain PA. As shown in the figure, the MAX2014
monitors the output of the PA through a directional cou-
pler. An internal integrator (Figure 2) compares the
detected signal with a reference voltage determined by
V
SET
. The integrator, acting like a comparator, increas-
es or decreases the voltage at OUT, according to how
closely the detected signal level matches the V
SET
ref-
erence. The MAX2014 adjusts the power of the PA to a
level determined by the voltage applied to SET. With R1 =
0Ω, the controller mode slope is approximately
19mV/dB (RF = 100MHz).
Layout Considerations
As with any RF circuit, the layout of the MAX2014 circuit
affects the device’s performance. Use an abundant num-
ber of ground vias to minimize RF coupling. Place the
input capacitors (C1, C2) and the bypass capacitors
(C3–C6) as close to the IC as possible. Connect the
bypass capacitors to the ground plane with multiple vias.
