LTC2919HDDB-5#PBF Linear Technology, LTC2919HDDB-5#PBF Datasheet - Page 9

• 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
If the user’s application requires, the SEL pin may be driven
using a three-state buffer which satisfi es the V
leakage conditions of this three-state input pin.
If the state of the SEL pin confi gures a given input as
“negative polarity,” the voltage at that ADJ pin must be
below the trip point (0.5V nominal), or the corresponding
OUT and RST output will be pulled low. Conversely, if a
given input is confi gured as “positive polarity”, the ADJ pin
voltage must be above the trip point or the corresponding
OUT and RST will assert low.
Thus, a “negative polarity” input may be used to deter-
mine whether a monitored negative voltage is smaller in
absolute value than it should be (–UV), or a monitored
positive voltage is larger than it should be (+OV). The
Table 2a. 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.
1.02M
30.9k
11.5k
R
R
309k
11.5k
R
R
R
R
N2A
N1A
309k
1 Positive UV, 1 Negative OV
P2
P1
P2A
P1A
–15V
15V
U
15V
1.02M
13.7k
11.8k
30.9k
R
R
R
R
115k
137k
2 Negative OV
2 Positive UV
R
R
P2B
P1B
N2B
N1B
N2
N1
SEL = V
U
–15V
–5V
5V
CC
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
W
OUT1
OUT2
OUT1
OUT2
OUT1
OUT2
SEL
SEL
SEL
UV (15V)
UV (5V)
OV (–15V)
OV (–5V)
UV (15V)
OV (–15V)
IL
U
, V
IH
and
opposite is true for a “positive polarity” input (–OV or
+UV). These polarity defi nitions are also shown in Table
1. For purposes of this data sheet, a negative voltage is
considered “undervoltage” if it is closer to ground than it
should be (e.g., –4.3V for a –5V supply).
Proper confi guration of the SEL pin and setting of the
trip-points via external resistors allows for any two fault
conditions to be detected. For example, the LTC2919 may
monitor two supplies (positive, negative or one of each)
for UV or for OV (or one UV and one OV). It may also
monitor a single supply (positive or negative) for both UV
and OV. Tables 2a and 2b show example confi gurations
for monitoring possible combinations of fault condition
and supply polarity.
10.7k
R
R
309k
N2A
N1A
R
R
619k
619k
R
R
20k
20k
1 Positive OV, 1 Negative UV
P2A
P1A
–15V
P2
P1
15V
15V
13.3k
13.7k
R
R
137k
R
133k
R
10.7k
2 Negative UV
309k
2 Positive OV
N2B
N1B
P2B
P1B
R
R
SEL = GND
N2
N1
–5V
–15V
5V
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
ADJ1
ADJ2
REF
OUT1
OUT2
OUT1
OUT2
OUT1
OUT2
SEL
SEL
SEL
LTC2919
UV (–15V)
UV (–5V)
OV (15V)
0V (5V)
OV (15V)
UV (–15V)
9
2919f