DS_6613_018
78M6613 Data Sheet
1.2.5 Temperature Sensor
The 78M6613 includes an on-chip temperature sensor implemented as a bandgap reference. It is used
to determine the die temperature. The MPU reads the temperature sensor output during alternate
multiplexer cycles. The primary use of the temperature data is to determine the magnitude of
compensation required to offset the thermal drift in the system (see Section 3.3 Temperature
Compensation).
1.2.6 Functional Description
The AFE functions as a data acquisition system, controlled by the MPU. The input signals (A0, A1, A2,
and A3) are sampled and the ADC counts obtained are stored in CE DRAM where they can be accessed
by the CE and, if necessary, by the MPU. Alternate multiplexer cycles are initiated less frequently by the
MPU to gather access to the slow temperature signal.
VREF
∆Σ ADC
CONVERTER
A0
A1
VBIAS
VBIAS
A2
MUX
A3
-
V3P3A
+
FIR
TEMP
VREF
VREF
MUX
CROSS
CK32
MUX
CTRL
4.9152 MHz
FIR_DONE
FIR_START
Figure 2: AFE Block Diagram
Rev. 1.1
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