AMC7836_15 Datasheet, PDF (70/87 Pages) Texas Instruments – AMC7836 High-Density, 12-Bit Analog Monitor and Control Solution With Multichannel ADC, Bipolar DACs, Temperature Sensor, and GPIO Ports

AMC7836
SLAS986B – NOVEMBER 2014 – REVISED FEBRUARY 2015
8 Application and Implementation
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NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The AMC7836 device is a highly integrated, low-power, analog monitoring and control solution that includes a
21-channel (12-bit) ADC, 16-channel (12-bit) DACs, eight GPIO, and a local temperature sensor. Although the
device can be used in many different closed-loop systems, including industrial control and test and
measurement, the device is largely used as a power amplifier controller in multi-channel RF communication
applications.
Power amplifiers (PAs) include transistor technologies that are extremely temperature sensitive, and require DC
biasing circuits to optimize RF performance, power efficiency, and stability. The AMC7836 device provides 16
DAC channels which can be used to adjust the power amplifier bias points in response to temperature changes.
The device also includes an internal local temperature sensor, and 21 ADC channels for general-purpose
monitoring.
Current and temperature sensing are typically implemented in power amplifier controller applications. PA drain
current sensing is implemented by measuring the differential voltage drop across a shunt resistor. Temperature
variations during PA operation can be detected either through the AMC7836 internal temperature sensor or
through remote temperature ICs or thermistors configured to interface with the ADC analog inputs available in
the device. Figure 114 shows the block diagram for these different systems.
AMC7836
MUX
ADC
GPIO
RF IN
Local
Temperature
Sensor
DAC
Power
Power
Amplifier
Current
Sense
Amplifier
Power
¨9
R(shunt)
RF IN
Power
Amplifier
Temperature
Sensor
Heat Sink
Heat Sink
Temperature Sensing
Current Sensing
Figure 114. AMC7836 Example Control and Monitor System
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