MAX2015 Maxim, MAX2015 Datasheet - Page 9

• Manufacturer Part Number: MAX2015
• Description: The MAX2015 complete multistage logarithmic amplifier is designed to accurately convert radio-frequency (RF) signal power in the 0
• Manufacturer: Maxim

detected signal with a reference voltage determined by
V
es or decreases the voltage at OUT, according to how
closely the detected signal level matches the V
erence. The MAX2015 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).
Figure 2. Controller-Mode Typical Application Circuit
SET
. The integrator, acting like a comparator, increas-
V
S
RFIN
R4
C6
C4
C5
C3
C1
C2
_______________________________________________________________________________________
1
2
3
4
V
INHI
INLO
V
CC
CC
DETECTORS
MAX2015
0.1GHz to 3GHz, 75dB Logarithmic
20kΩ
20kΩ
PWDN
GND
OUT
SET
8
7
6
5
V
V
SET
OUT
SET
ref-
As with any RF circuit, the layout of the MAX2015 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.
Figure 3. System Diagram for Automatic Gain-Control Loop
TRANSMITTER
SET-POINT
Detector/Controller
DAC
POWER AMPLIFIER
OUT
SET
GAIN-CONTROL INPUT
Layout Considerations
20kΩ
20kΩ
MAX2015
LOGARITHMIC
DETECTOR
IN
COUPLER
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