X40030_06 Datasheet, PDF (7/24 Pages) Intersil Corporation – Triple Voltage Monitor with Integrated CPU Supervisor

X40030, X40031, X40034, X40035
returns and exceeds V_TRIP2.This voltage sense cir-
cuitry monitors the power supply connected to V2MON
pin. If V_CC = 0, V2MON can still be monitored.
For the X40034 and X40035, the V2FAIL signal
remains active until V_CC drops below 1V and remains
active until V2MON returns and exceeds V_TRIP2.This
sense circuitry is powered by V_CC. If V_CC = 0, V2MON
cannot be monitored.
Low Voltage V3 Monitoring
The X40030, X40031, X40034, X40035 also monitors
a third voltage level and asserts V3FAIL if the voltage
falls below a preset minimum V_TRIP3. The V3FAIL sig-
nal is either ORed with RESET to prevent the micro-
processor from operating in a power fail or brownout
condition or used to interrupt the microprocessor with
notification of an impending power failure. The V3FAIL
signal remains active until the V3MON drops below 1V
(V3MON falling). It also remains active until V3MON
returns and exceeds V_TRIP3.
This voltage sense circuitry monitors the power supply
connected to V3MON pin. If V_CC = 0, V3MON can still
be monitored.
Figure 2. Two Uses of Multiple Voltage Monitoring
6-10V
1M
V_CC
X40031-A
5V _{VCC RESET}
3.3V
390K
V2MON V2FAIL
V3MON
(1.7V) _V3FAIL
System
Reset
Power
Fail
Interrupt
Unreg.
Supply
5V
Reg
3.0V
Reg
1.8V
Reg
V_CC
X40031-B
V_CC
RESET
V2MON
V2FAIL
V3MON
V3FAIL
System
Reset
Early Low V_CC Detection (LOWLINE)
This CMOS output goes LOW earlier than
RESET/RESET whenever V_CC falls below the V_TRIP1
voltage and returns high when V_CC exceeds the
V_TRIP1 voltage. There is no power up delay circuitry
(t_PURST) on this pin.
Notice: No external components required to monitor three voltages.
Figure 3. V_TRIPX Set/Reset Conditions
V_TRIPX
(X = 1, 2, 3)
V_CC/V2MON/V3MON
V_P
WDO
SCL
0
70
70
7
SDA
A0h
00h
t_WC
7
FN8114.1
May 25, 2006