ISL88031 Intersil Corporation, ISL88031 Datasheet - Page 4

• Manufacturer Part Number: ISL88031
• Description: Quintuple Voltage Monitor
• Manufacturer: Intersil Corporation

Electrical Specifications
Pin Description
RST
The RST output is an open drain output which is asserted
low whenever
MR
The MR input is an active low debounced input to which a
user can connect a push-button to add manual reset
capability or use a signal to pull low. MR has an internal pull-
up resistor.
V
The V
this pin is compared against an internal factory-programmed
voltage trip point, V
device is initially powered and V
time thereafter when V
designed with hysteresis to help prevent chattering due to
noise and is immune to brief power-supply transients.
V2MON
The V2MON input is the second preset monitored voltage
that causes the RST output to go low when the voltage on
V2MON falls below V
V3MON, V4MON, and V5MON
The VxMON inputs provide monitoring and UV compliance
of three additional voltages through resistor dividers. A reset
is issued on the ISL88031 if the voltage on any VxMON falls
below the internal V
MANUAL RESET
1. the device is initially powered up to 1V or
2. V
SYMBOL
DD
V
V
their minimum voltage sense level.
R
t
MRH
MRL
MR
DD
PU
DD
, V2MON, V3MON, V4MON, or V5MON fall below
pin is the IC power supply terminal. The voltage at
MR Input Voltage Low
MR Input Voltage High
MR Minimum Pulse Width
Internal Pull-Up Resistor
TH1
REF
TH2
DD
. RST is first asserted low when the
of 0.6V.
.
falls below V
PARAMETER
4
Over the recommended operating conditions unless otherwise specified. (Continued)
DD
< 1 V and then at any
TH1
. The device is
ISL88031
TEST CONDITIONS
V
Principles of Operation
The ISL88031 device provide those functions needed for
monitoring critical voltages such as power-supply and battery
functions in microprocessor systems. It provides such features
as Power On Reset control, Supply Voltage Supervision, and
Manual Reset Assertion. The integration of all these features
along with competitive reset threshold accuracy and low power
consumption make the ISL88031 device suitable for a wide
variety of applications needing multi-voltage monitoring.
See Figure 1 for typical application diagram.
Low Voltage Monitoring
During normal operation, the ISL88031 monitors the voltage
levels of V
voltage on any of these five inputs falls below their respective
voltage trip points, a reset is asserted (RST = low) to prevent
the microprocessor from operating during a power failure or
brownout condition. This reset signal remains low until the
voltages exceeds the voltage threshold settings for the reset
time delay period t
The ISL88031 allows users to customize the minimum voltage
sense level for three of the five monitored voltages. For
example, the user can adjust the voltage input trip point (V
for V3MON, V4MON and V5MON inputs. To do this, connect
an external resistor divider network to the VxMON pin in order
to set the trip point to some other voltage above 600mV
according to the following formula:
TRIP
V4MON
= 0.6V X (R1 + R2) / R2
FIGURE 1. TYPICAL APPLICATION DIAGRAM
DD
V5MON
V2MON
V3MON
, V2MON, V3MON, V4MON, and V5MON. If the
V
DD
POR
V
.
DD
MIN
550
-0.6
ISL88031
GND
TYP
10
RST
MAX
MR
0.8
PB
March 31, 2006
reset
signal
UNITS
FN8227.0
kΩ
ns
TRIP
V
V
)