x9523v20iz-bt1 Intersil Corporation, x9523v20iz-bt1 Datasheet - Page 15

• Manufacturer Part Number: x9523v20iz-bt1
• Description: Dual Dcp, Por, Dual Voltage Monitors
• Manufacturer: Intersil Corporation

Setting a Lower V
In order to set V
present value, then V
ing to the procedure described below. Once V
has been “reset”, then V
voltage using the procedure described in “Setting a
Higher V
Resetting the V
To reset a V
age (Vp) to the WP pin before a START condition is set
up on SDA. Next, issue on the SDA pin the Slave
Address A0h followed by the Byte Address 03h for
V
by 00h for the Data Byte in order to reset V
STOP bit following a valid write operation initiates the
programming sequence. Pin WP must then be brought
LOW to complete the operation (See Figure 18).The
user does not have to set the WEL bit in the CON-
STAT register before performing this write sequence.
After being reset, the value of V
nal value of 1.7V.
V
The accuracy with which the V
can be controlled using the iterative process shown in
Figure 19.
If the desired threshold is less that the present threshold
voltage, then it must first be “reset” (See "Resetting the
VTRIPx Voltage (x = 1,2,3)." ) .
The desired threshold voltage is then applied to the
appropriate input pin (V1/Vcc, V2 or V3) and the proce-
dure described in Section “Setting a Higher V
Voltage“ must be followed.
Once the desired V
error between the desired and (new) actual set threshold
can be determined. This is achieved by applying V1/Vcc
to the device, and then applying a test voltage higher
than the desired threshold voltage, to the input pin of the
voltage monitor circuit whose V
For example, if V
then a test voltage of 3.4 V may be applied to the voltage
monitor input pin V2. In the case of setting of V
only V1/Vcc need be applied. In all cases, care should be
taken not to exceed the maximum input voltage limits.
TRIP1
TRIPx
, 0Bh for V
Accuracy (x = 1,2,3).
TRIPx
TRIPx
Voltage”.
TRIP2
voltage, apply the programming volt-
TRIP2
TRIPx
TRIPx
TRIPx
TRIPx
TRIPx
was set to a desired level of 3.0V,
, and 0Fh for V
Voltage (x = 1,2,3).
TRIPx
to a lower voltage than the
Voltage (x = 1,2,3).
15
threshold has been set, the
must first be “reset” accord-
can be set to the desired
TRIPx
TRIPx
TRIPx
thresholds are set,
was programmed.
becomes a nomi-
TRIP3
TRIPx
, followed
TRIP1
. The
TRIPx
TRIPx
then
X9523
After applying the test voltage to the voltage monitor
input pin, the test voltage can be decreased (either in dis-
crete steps, or continuously) until the output of the volt-
age monitor circuit changes state. At this point, the error
between the actua measured, and desired threshold lev-
els is calculated.
For example, the desired threshold for V
3.0V, and a test voltage of 3.4V was applied to the input
pin V2 (after applying power to V1/Vcc). The input volt-
age is decreased, and found to trip the associated output
level of pin V2RO from a LOW to a HIGH, when V2
reaches 3.09V. From this, it can be calculated that the
programming error is 3.09 - 3.0 = 0.09V.
If the error between the desired and measured V
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
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
a value equal to the previously set V
culated error. If it is the case that the error is less than
zero, then the V
equal to the previously set V
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
age equal to the last previously programmed voltage,
minus the last previously calculated error. Therefore, we
must apply V
programming sequence (See "Setting a Higher VTRIPx
Voltage (x = 1,2,3)" ) .
Using this process, the desired accuracy for a particu-
lar V
sive number of iterations.
TRIPx
TRIPx
must first be “reset”, and then programmed to the
threshold may be attained using a succes-
TRIP2
TRIPx
TRIPx
= 2.91 V to pin V2 and execute the
TRIP2
must be programmed to a value
programming sequence can be
TRIPx
threshold, then apply a volt-
plus the absolute value
TRIPx
TRIP2
minus the cal-
January 3, 2006
is set to
TRIPx
FN8209.1
is