X9520 Datasheet, PDF (19/33 Pages) Intersil Corporation – Triple DCP, POR,2kbit EEPROM Memory, Dual Voltage Monitors

X9520
If the error between the desired and measured V_TRIPx is
less than the maximum desired error, then the program-
ming process may be terminated. If however, the error is
greater than the maximum desired error, then another
iteration of the V_TRIPx programming sequence can be
performed (using the calculated error) in order to further
increase the accuracy of the threshold voltage.
If the calculated error is greater than zero, then the
V_TRIPx must first be “reset”, and then programmed to the
a value equal to the previously set V_TRIPx minus the cal-
culated error. If it is the case that the error is less than
zero, then the V_TRIPx must be programmed to a value
equal to the previously set V_TRIPx plus the absolute
value of the calculated error.
Continuing the previous example, we see that the calcu-
lated error was 0.09V. Since this is greater than zero, we
must first “reset” the V_TRIP2 threshold, then apply a volt-
age equal to the last previously programmed voltage,
minus the last previously calculated error. Therefore, we
must apply V_TRIP2 = 2.91 V to pin V2 and execute the
programming sequence ( ) .
Using this process, the desired accuracy for a particu-
lar V_TRIPx threshold may be attained using a succes-
sive number of iterations.
V_TRIPx Programming
New Vx applied =
Old Vx applied + | Error |
NO
Desired V_TRIPx <
present value?
YES
Execute
V_TRIPx Reset
Sequence
Set Vx = desired V_TRIPx
Execute
Set Higher V_TRIPx
Sequence
Apply Vcc & Voltage
> Desired V_TRIPx to Vx
Decrease Vx
Note: X = 1,2,3.
Let: MDE = Maximum Desired Error
MDE⁺
Desired Value
MDE^–
Acceptable
Error Range
Error = Actual - Desired
New Vx applied =
Old Vx applied - | Error |
Execute
Reset V_TRIPx
Sequence
NO
Output
switches?
YES
Error < MDE^–
Actual V_TRIPx
- Desired V_TRIPx
= Error
Error >MDE⁺
| Error | < | MDE |
DONE
Figure 24. V_TRIPx Setting / Reset Sequence (x=1,2,3)
19
FN8206.0
March 8, 2005