X4043 INTERSIL [Intersil Corporation], X4043 Datasheet - Page 6

• Manufacturer Part Number: X4043
• Description: CPU Supervisor with 4kbit EEPROM
• Manufacturer: INTERSIL [Intersil Corporation]

Setting a V
There are two procedures used to set the threshold
voltages (V
be stored is higher or lower than the present value. For
example, if the present V
V
into the V
lower than the present setting, then it is necessary to
“reset” the V
Setting a Higher V
To set a V
higher than the present threshold, the user must apply
the desired V
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 01h for V
Data Byte in order to program V
following a valid write operation initiates the program-
ming sequence. WP pin must then be brought LOW to
complete the operation.
To check if the V
the device. Slowly ramp up V
output, RESET (4043) or RESET (4045) switches. The
voltage at which this occurs is the V
Figure 2).
C
Now if the desired V
(actual), then add the difference between V
(desired) - V
This is your new V
and the whole sequence should be repeated again
(see Figure 5).
TRIP
ASE
is 3.2 V, the new voltage can be stored directly
A
TRIP
TRIP
TRIP
TRIP
TRIP
TRIP
TRIP
cell. If however, the new setting is to be
), depending if the threshold voltage to
Voltage
threshold to a new voltage which is
voltage before setting the new value.
(actual) to the original V
TRIP
threshold voltage to the V
TRIP
TRIP
TRIP
has been set, first power-down
Voltage
that should be applied to V
TRIP
6
is greater than the V
CC
is 2.9 V and the new
and observe when the
TRIP
TRIP
. The STOP bit
TRIP
TRIP
(actual) (see
and a 00h
CC
desired.
. Then,
X4043, X4045
TRIP
TRIP
CC
C
Now if the V
(desired), perform the reset sequence as described in
the next section. The new V
V
(desired)).
Note: This operation does not corrupt the memory
array.
Setting a Lower V
In order to set V
present value, then V
ing to the procedure described below. Once V
been “reset”, then V
age 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 fol-
lowed by 00h for the Data Byte in order to reset V
The STOP bit following a valid write operation initiates
the programming sequence. Pin WP must then be
brought LOW to complete the operation.
After being reset, the value of V
nal value of 1.7V or lesser.
Note: This operation does not corrupt the memory
array.
CC
TRIP
ASE
will now be: V
Voltage”.
B
TRIP
TRIP
TRIP
voltage, apply the programming volt-
TRIP
TRIP
TRIP
(actual), is higher than the V
TRIP
Voltage
TRIP
(desired) - (V
Voltage
to a lower voltage than the
can be set to the desired volt-
must first be “reset” accord-
TRIP
voltage to be applied to
TRIP
TRIP
becomes a nomi-
(actual) - V
September 30, 2005
TRIP
FN8118.1
TRIP
TRIP
TRIP
has
.