MAX2203 Maxim, MAX2203 Datasheet - Page 6

• Manufacturer Part Number: MAX2203
• Description: The MAX2203 RMS power detector is designed to operate from 800MHz to 2
• Manufacturer: Maxim

RMS Power Detector
Figure 1. System Level Connection
The MAX2203 uses external termination when using
directional couplers. Figure 1 shows the system level
connection of dual-band power detection. The output of
the detector is typically connected to an ADC in
cdma2000 or WCDMA power-control topology.
The MAX2203 features an enable input (ENA) that
allows the device to be put into shutdown. For normal
operation, drive ENA high. For device shutdown, drive
ENA low. The ENA pin is DC biased through a resistor.
The value of the resistor is recommended to be greater
than 1kΩ to avoid loading the RF input signal. There is
an internal resistor to GND of approximately 50kΩ. If
the control source high voltage is greater than 2.8V,
calculate and use a resistor value that ensures the ENA
pin only sees a maximum of 2.7V, which is within speci-
fication. In this manner, the MAX2203 can be driven
from a control device with a logic-high greater than
2.8V.
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Applications Information
50Ω
50Ω
Enable Logic Level
ENABLE
COUPLER 1
COUPLER 2
DETECT
RMS
BIAS
10Ω
10Ω
The MAX2203 is not particularly sensitive to the layout
since it only needs 3dBm for maximum output voltage.
However, there are two areas that need attention: the
GND pins and the supply bypassing. Connect the GND
pins to the PCB ground with a ground via as close as
possible, and bypass V
as close as possible to the part.
PROCESS: BiCMOS
MAX2203
BUFFER
PA 1
PA 2
DETECTOR
OUTPUT
CC
to ground with a capacitor
Chip Information
Layout