ISL88042 Intersil Corporation, ISL88042 Datasheet - Page 4

• Manufacturer Part Number: ISL88042
• Description: Quadruple Voltage Monitor
• Manufacturer: Intersil Corporation

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Electrical Specifications
Pin Descriptions
RST
The RST output is an open drain output, which is asserted
low whenever the following occurs:
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, and V4MON
The VxMON inputs provide monitoring and UV compliance
of three additional voltages through resistor dividers. A reset
is issued on the ISL88042 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
t
minimum voltage sense level.
R
POR
t
MRH
MRL
MR
DD
PU
DD
, V2MON, V3MON or V4MON fall below their
pin is the IC power supply terminal. The voltage at
POR Timeout Delay
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. Parameters with MIN and/or MAX
limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested. (Continued)
DD
< 1V and then at any
TH1
. The device is
V3MON, V4MON < 3V
ISL88042
TEST CONDITIONS
.
Principles of Operation
The ISL88042 device provides 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, makes the ISL88042 device suitable for a wide
variety of applications needing multi-voltage monitoring. See
Figure 1 for the “Typical Application Diagram”.
Low Voltage Monitoring
During normal operation, the ISL88042 monitors the voltage
levels of V
any of these four 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 ISL88042 allows users to customize the minimum voltage
sense level for two of the four monitored voltages. For example,
the user can adjust the voltage input trip point (V
V3MON and V4MON inputs. To do this, connect an external
resistor divider network to the VxMON pin in order to set the trip
V3MON
FIGURE 1. TYPICAL APPLICATION DIAGRAM
DD
V2MON
V4MON
, V2MON, V3MON and V4MON. If the voltage on
V
DD
POR
V
.
DD
MIN
550
40
- 0.6
ISL88042
GND
TYP
95
10
RST
MAX
MR
150
0.8
PB
TRIP
) for the
June 8, 2009
RESET
SIGNAL
UNITS
FN6655.1
ms
kΩ
ns
V
V