
43
5360A–BDC–06/05
TS83102G0BMGS
9.7.4
Pattern Generator Function
The pattern generator function (enabled by connecting pin A9 PGEB to V
EE = -5V) allows you to
rapidly check the ADC’s operation thanks to a checker board pattern delivered internally to the
ADC. Each of the ADC’s output bits should toggle from 0 to 1
successively, giving sequences such as 0101010101 and 1010101010 every 2 cycles.
The out of range bit also toggles when the pattern generator is active. Even bits as well as the
out of range bit are low on low to high transition of the data ready signal.
9.7.5
DECB/DIODE: Junction Temperature Monitoring and Output Decimation Enable
The DECB/DIODE pin is provided to enable the decimation function and monitor the die junction
temperature.
When connected to V
EE = -5V, the ADC runs in “decimation by 32” mode (1 out of 32 data is out-
put from the ADC, thus reducing the data rate by 32).
When the DECB/DIODE pin is left floating, then the ADC is said to be in a "normal" mode of
operation (the output data is not decimated) and can be used for die junction temperature moni-
toring only.
If you do not intend to use the die junction temperature monitoring function, the DECB/DIODE
pin (A10) has to be left either floating or connected to ground.
The decimation function can be used to debug the ADC at initial stages. This function enables
you to reduce the ADC output rate by 32, thus reducing the time of the ADC’s debug phase at
the maximum speed rate, and is compatible with industrial testing environments.
When this function is active, the ADC outputs only 1 out of 32 bits of data, resulting in a data rate
32 times slower than the clock rate.
Note:
The ADC decimation test mode is different from the pattern generator function, which is used to
check the ADC’s outputs.
9.7.6
External Configuration Description
Because of the use of one internal diode-mounted transistor (used for junction temperature
monitoring), you have to implement external head-to-tail protection diodes so as to avoid poten-
tial reverse current flows, which can damage the internal diode component.
Two external configurations are possible:
Configuration 1: allows both junction temperature monitoring and output data decimation.
Configuration 2: allows junction temperature monitoring only.
9.7.6.1
Configuration 1
This external configuration allows you to apply the requested levels to activate output data deci-
mation (V
EE = -5V) and at the same time monitor the junction temperature diode (this explains
why 7 protection diodes are needed in the other direction, as shown in Figure 51).