LTC2919HDDB-5#PBF Linear Technology, LTC2919HDDB-5#PBF Datasheet - Page 10

• Manufacturer Part Number: LTC2919HDDB-5#PBF
• Manufacturer: Linear Technology

Specifications of LTC2919HDDB-5#PBF

• Voltage Supervisor Type: Voltage Monitor
• Number Of Voltage Supervisors: 2
• Monitored Supervisor Voltage: 3.3
• Operating Supply Voltage (min): 0.5V
• Operating Temperature Classification: Automotive
• Operating Temp Range: -40C to 125C
• Pin Count: 10
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Compliant

APPLICATIO S I FOR ATIO
LTC2919
Table 2b. Possible Combinations of Supply Monitoring. For Example Purposes, All Supplies are Monitored at 5% Tolerance and
Connections are Shown Only for ADJ1, ADJ2, REF , SEL, OUT1 and OUT2. Output Pull-up Resistors are Omitted for Clarity.
10
Adjust Input Trip Point
The trip threshold for the supplies monitored by the
adjustable inputs is set with an external resistor divider,
allowing the user complete control over the trip point.
Selection of this trip voltage is crucial to the monitoring
of the system.
Any power supply has some tolerance band within which
it is expected to operate (e.g., 5V ±10%). It is generally
undesirable that a supervisor issue a reset when the power
supply is inside this tolerance band. Such a “nuisance”
reset reduces reliability by preventing the system from
functioning under normal conditions.
11.5k
309k
11.5k
R
R
R
309k
R
P2
P1
1 Positive UV, 1 Negative UV
P2A
P1A
1 Positive UV, 1 Positive OV
2.37M
10.7k
76.8k
15V
U
15V
R
R
R
1 Positive UV and OV
P6
P5
P4
15V
10.7k
13.7k
R
R
309k
133k
R
R
P2B
P1B
N1
N2
U
–15V
5V
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
OUT1
OUT2
SEL
W
OUT1
OUT2
OUT1
OUT2
SEL
SEL
UV
OV
UV (15V)
UV (–15V)
UV (15V)
OV (5V)
U
SEL OPEN
To prevent nuisance resets, the supervisor threshold must
be guaranteed to lie outside the power supply tolerance
band. To ensure that the threshold lies outside the power
supply tolerance range, the nominal threshold must lie out-
side that range by the monitor’s accuracy specifi cation.
All three of the LTC2919 inputs (ADJ1, ADJ2, V
have the same maximum threshold accuracy of ±1.5% of
the programmed nominal input voltage (over the full operat-
ing temperature range). Therefore, using the LTC2919, the
typical 10% UV threshold is at 11.5% below the nominal
input voltage level. For a 5V input, the threshold is nominally
4.425V. With ±1.5% accuracy, the trip threshold range is
4.02k
R
N5
1.02M
30.9k
R
R
1.02M
30.9k
30.9k
N2A
N1A
1 Negative UV, 1 Negative OV
1 Negative OV, 1 Positive OV
R
R
R
–15V
N4
N2
N1
–15V
1 Negative UV and OV
1.02M
13.3k
R
R
619k
137k
R
R
R
20k
N2B
N1B
N6
P2
P1
–15V
15V
–5V
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
OUT1
OUT2
OUT1
OUT2
OUT1
OUT2
SEL
SEL
SEL
OV
UV
OV (–15V)
OV (15V)
OV (–15V)
UV (–5V)
CC
UVLO)
2919f