Application Information
TSEV83102G0B - Evaluation Board User Guide
4-3
2166B–BDC–04/03
4.7
Die Junction
Temperature
Monitoring
Figure 4-2 and Figure 4-3 illustrate the recommanded implementation of the die junction
temperature monitoring function for the Revision B of the 10-bit 2 Gsps ADC.
The user has the choice between two possible configurations:
1.
The ADC decimation test mode is NOT ALLOWED.
Because of the use of 1 internal diode-mounted transistors, the user has to implement
2 x 2 head-to-tail protection diodes to avoid potential reverse current flows to damage
the diode pin.
Note that Atmel usually recommends the use of 2 x 3 head-to-tail protection diodes but
in this particular case, it is necessary to have exactly 2 diodes in the A10 to ground
direction of conduction.
Figure 4-2. Recommended Die Junction Temperature Monitoring Function Implemen-
tation, Test Mode Not Allowed
2.
The ADC test mode can be allowed
In case the user wants to still be able to switch from the normal mode to the test mode or
to the die junction temperature monitoring, the protection diode configuration is slightly
different and takes into account the fact that the test mode can be activated by applying
V
EE
= -5V to the diode pin.
This explains why 7 protection diodes are needed in the other direction, as described in
Figure 4-3.
Figure 4-3. Recommended Diode Pin Implementation Allowing for Both Die Junction
Temperature Monitoring Function and Test Mode
A10
GND
Idiode
IGND
ADC Pin
1 mA
Vdiode
VGND
V
A10
GND
Idiode
IGND
ADC Pin
1 mA
Vdiode
VGND
V
