LTC1728ES5-5#TR Linear Technology, LTC1728ES5-5#TR Datasheet - Page 11

• Manufacturer Part Number: LTC1728ES5-5#TR
• Description: IC MON TRPL MCRPWR TSOT23-5
• Manufacturer: Linear Technology
• Type: Multi-Voltage Supervisorr

Specifications of LTC1728ES5-5#TR

• Number Of Voltages Monitored: 3
• Output: Open Drain or Open Collector
• Reset: Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 3.086V, 4.675V, Adj
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-5, TSOT-5, TSOP-5
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

applicaTions inForMaTion
Override Functions (5V Versions Only)
The V
V
V
for V
The V
equal to the voltage on V
V
LTC1728-5 will behave as a 3.3V monitor and V
capability will be disabled.
The V
V
two inputs are greater than approximately 4.15V. In this
manner, the part can function as a 5V monitor with the
3.3V monitor disabled.
CC5
CC3
CC5
CC5
. This is an obvious solution since the trip points for
CCA
and V
is less than 4.15V. In this manner, the LTC1727-5/
is equal to the voltage on V
CCA
CC5
CC5
.
pin, if unused, can be tied to either V
trip point is reenabled when the voltage on
input trip point is disabled if its voltage is
CC5
will always be greater than the trip point
CC3
± 25mV and the voltage on
3.3V OR 5V
Figure 2. Single Supply Monitor with Others Disabled
CC3
V
± 25mV and the
CC
Figure 3. RST Voltage vs Supply Voltage
1
5
4
3
2
0
0
V
10k PULL-UP FROM RST TO V
CC3
CC5
= V
1
5
4
3
2
CC3
CC5
reset
V
V
V
GND
SUPPLY VOLTAGE (V)
CC3
CC5
CCA
= V
LTC1728-5
or
CCA
2
= 0V TO 5V
RST
When monitoring either 3.3V or 5V with V
to V
appropriate range. The part handles this situation as
shown in Figure 3. Above 1V and below V
low. From V
3.3V supply monitoring and RST is deasserted. Above
approximately 4.15V the part operates as a 5V monitor.
In most systems the 5V supply will pass through the
3.1V to 4.15V region in <200ms during power-up, and
the RST output will behave as desired. Table 1 summa-
rizes the state of RST at various operating voltages with
V
Table 1. Override Truth Table (V
INPUTS (V
0V ≤ V
1V ≤ V
V
4.15V ≤ V
V
3
RT3
RT5
CC3
1
CC3
≤ V
≤ V
CC5
CC
CC
= V
CC
CC
4
≤ 1V
≤ V
CC
(see Figure 2), the part determines which is the
CC3
1727/28 F03
≤ 4.15V
R1
10k
CC5
≤ V
RT3
= V
RT3
.
RT5
5
TO SYSTEM
RESET
CC5
to approximately 4.15V the part assumes
= V
1727/28 F02
CC
LTC1727/LTC1728
)
CC3
= V
CC5
)
RT3
CC3
, RST is held
strapped
RST
—
0
1
0
1
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