X9520_07 Datasheet, PDF (16/29 Pages) Intersil Corporation – Triple DCP, POR, 2kbit EEPROM Memory, Dual Voltage Monitors

X9520
X9520 Write Permission Status
BLOCK
LOCK BITS
BL0 BL1
x
1
1
x
0
0
DCP VOLATILE WRITE
WP
PERMITTED
1
NO
1
NO
1
YES
DCP NONVOLATILE
WRITE PERMITTED
NO
NO
NO
x
1
0
1
x
0
0
0
0
NO
NO
YES
NO
NO
YES
WRITE TO EEPROM
PERMITTED
NO
NO
NO
Not in locked region
Not in locked region
Yes (All Array)
WRITE TO CONSTAT REGISTER
PERMITTED
VOLATILE BITS
NONVOLATILE
BITS
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
Vx
V_TRIPx
0V
VxRO
0V
V1/VCC
0 Volts
V_TRIP1
(x = 2,3)
FIGURE 21. VOLTAGE MONITOR RESPONSE
V2 Monitoring
The X9520 asserts the V2RO output HIGH if the voltage V2
exceeds the corresponding V_TRIP2 threshold (See Figure
21). The bit V2OS in the CONSTAT register is then set to a
“0” (assuming that it has been set to “1” after system
initilization).
The V2RO output may remain active HIGH with V_CC down to
1V.
V3 Monitoring
The X9520 asserts the V3RO output HIGH if the voltage V3
exceeds the corresponding V_TRIP3 threshold (See Figure
21). The bit V3OS in the CONSTAT register is then set to a
“0” (assuming that it has been set to “1” after system
initilization).
The V3RO output may remain active HIGH with V_CC down to
1V.
V_TRIPx Thresholds (x = 1,2,3)
The X9520 is shipped with pre-programmed threshold
(V_TRIPx) voltages. In applications where the required
thresholds are different from the default values, or if a higher
precision/tolerance is required, the X9520 trip points may be
adjusted by the user, using the steps detailed below.
Setting a V_TRIPx Voltage (x = 1,2,3)
There are two procedures used to set the threshold voltages
(V_TRIPx), depending if the threshold voltage to be stored is
higher or lower than the present value. For example, if the
present V_TRIPx is 2.9 V and the new V_TRIPx is 3.2 V, the
new voltage can be stored directly into the V_TRIPx cell. If
however, the new setting is to be lower than the present
setting, then it is necessary to “reset” the V_TRIPx voltage
before setting the new value.
Setting a Higher V_TRIPx Voltage (x = 1,2,3)
To set a V_TRIPx threshold to a new voltage which is higher
than the present threshold, the user must apply the desired
V_TRIPx threshold voltage to the corresponding input pin
(V1/VCC, 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 01h for V_TRIP1, 09h for
V_TRIP2, and 0Dh for V_TRIP3, and a 00h Data Byte in order to
program V_TRIPx. The STOP bit following a valid write
operation initiates the programming sequence. Pin WP must
then be brought LOW to complete the operation (See Figure
23). The user does not have to set the WEL bit in the
CONSTAT register before performing this write sequence.
Setting a Lower V_TRIPx Voltage (x = 1,2,3).
In order to set V_TRIPx to a lower voltage than the present
value, then V_TRIPx must first be “reset” according to the
procedure described below. Once V_TRIPx has been “reset”,
then V_TRIPx can be set to the desired voltage using the
procedure described in “Setting a Higher V_TRIPx Voltage”.
Resetting the V_TRIPx Voltage (x = 1,2,3).
To reset a V_TRIPx voltage, apply the programming voltage
(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_TRIP1, 0Bh for V_TRIP2, and
0Fh for V_TRIP3, followed by 00h for the Data Byte in order to
reset V_TRIPx. The STOP bit following a valid write operation
16
FN8206.2
August 20, 2007