x9522v20iz-bt1 Intersil Corporation, x9522v20iz-bt1 Datasheet - Page 14

• Manufacturer Part Number: x9522v20iz-bt1
• Description: Triple Dcp, Dual Voltage Monitors
• Manufacturer: Intersil Corporation

Setting a Higher V
To set a V
higher than the present threshold, the user must apply
the desired V
sponding input pin (V2 or V3). Then, a programming
voltage (Vp) must be applied 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 09h for V
Data Byte in order to program V
following a valid write operation initiates the program-
ming sequence. Pin WP must then be brought LOW to
complete the operation (See Figure 16). The user
does not have to set the WEL bit in the CONSTAT reg-
ister before performing this write sequence.
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 0Bh for
V
Data Byte in order to reset V
lowing a valid write operation initiates the program-
ming sequence. Pin WP must then be brought LOW to
complete the operation (See Figure 16).The user does
not have to set the WEL bit in the CONSTAT 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 17.
If the desired threshold is less that the present threshold
voltage, then it must first be “reset” (See "Resetting the
VTRIPx Voltage").
The desired threshold voltage is then applied to the
appropriate input pin (V2 or V3) and the procedure
described in Section “Setting a Higher V
must be followed.
TRIP2
TRIPx
, and 0Fh for V
Accuracy (x = 2,3)
TRIPx
TRIPx
TRIPx
Voltage”.
TRIPx
threshold to a new voltage which is
TRIP3
voltage, apply the programming volt-
TRIPx
TRIPx
TRIPx
threshold voltage to the corre-
TRIPx
TRIPx
, and 0Dh for V
TRIP3
Voltage (x = 2,3)
TRIPx
to a lower voltage than the
Voltage
14
must first be “reset” accord-
Voltage (x = 2,3)
, followed by 00h for the
can be set to the desired
TRIPx
TRIPx
TRIPx
TRIPx
. The STOP bit fol-
thresholds are set,
becomes a nomi-
TRIP3
. The STOP bit
TRIPx
, and a 00h
Voltage“
TRIPx
X9522
Once the desired V
error between the desired and (new) actual set threshold
can be determined. This is achieved by applying Vcc / V1
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 all cases, care should be taken
not to exceed the maximum input voltage limits.
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 actual / measured, and desired threshold
levels is calculated.
For example, the desired threshold for V
3.0 V, and a test voltage of 3.4 V was applied to the input
pin V2 (after applying power to Vcc / V1). 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 3.09 V. From this, it can be calculated that the
programming error is 3.09 - 3.0 = 0.09 V.
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 = 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-
TRIP1
TRIP2
TRIPx
TRIPx
= 2.91 V to pin V2 and execute the
TRIPx
TRIP2
was set to a desired level of 3.0 V,
must be programmed to a value
programming sequence can be
threshold has been set, the
TRIPx
threshold, then apply a volt-
TRIPx
plus the absolute value
TRIPx
was programmed.
TRIP2
minus the cal-
January 3, 2006
is set to
TRIPx
FN8208.1
is