X40430 Datasheet, PDF (4/24 Pages) Intersil Corporation – Triple Voltage Monitor with Integrated CPU Supervisor

X40430/X40431 – Preliminary Information
Low Voltage V_CC (V1 Monitoring)
During operation, the X40430 monitors the V_CC level
and asserts RESET if supply voltage falls below a pre-
set minimum V_TRIP1. The RESET signal prevents the
microprocessor from operating in a power fail or
brownout condition. The RESET/RESET signal
remains active until the voltage drops below 1V. It also
remains active until V_CC returns and exceeds V_TRIP1
for t_PURST.
Low Voltage V2 Monitoring
The X40430 also monitors a second voltage level and
asserts V2FAIL if the voltage falls below a preset mini-
mum V_TRIP2. The V2FAIL signal is either ORed with
RESET to prevent the microprocessor from operating
in a power fail or brownout condition or used to inter-
rupt the microprocessor with notification of an impend-
ing power failure. The V2FAIL signal remains active
until the V2MON drops below 1V (V2MON falling). It
also remains active until V2MON returns and exceeds
V_TRIP2 by 0.2V.
Low Voltage V3 Monitoring
The X40430 also monitors a third voltage level and
asserts V3FAIL if the voltage falls below a preset mini-
mum V_TRIP3. The V3FAIL signal is either ORed with
RESET to prevent the microprocessor from operating
in a power fail or brownout condition or used to inter-
rupt the microprocessor with notification of an impend-
ing 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 by 0.2V.
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 volt-
age. There is no power up delay circuitry (t_PURST) on
this pin.
Figure 2. Two Uses of Multiple Voltage Monitoring
Unreg.
Supply
R
R
X40430
5V
V_CC
Reg
RESET
V2MON
V2FAIL
V2MON
System
Reset
Resistors selected so 3V appears on V2MON when unregulated
supply reaches 6V.
Unreg.
Supply
5V
Reg
4V
Reg
3V
Reg
X40431
V2MON
V_CC V3MON
V_CC
RESET
V2MON
V2FAIL
System
Reset
V3MON
V3FAIL
Notice: No external components required to monitor three voltages.
REV 1.2.3 11/28/00
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