LTC2960
TYPICAL APPLICATIONS
The LTC2960-2 in Figure 10 is yet another way to prevent
excessive discharge of a battery. The high voltage OUT
output is used to drive the gate of a PMOS switch to in-
Micropower Power Supply Sequencer and Supervisor
Figure 13 illustrates multiple uses for the LTC2960 in a
power supply system. U1 is a power supply sequencer
terrupt the path to V
in the event of an undervoltage
+
OUT
whose IN input monitors V and enables the 5V switch-
IN
condition. When the battery stack voltage is above the
ing regulator. The ADJ input monitors the output of the
5V switching regulator and enables the 1.8V LDO after a
16ms Reset Timeout Period. U2 is a supervisor monitor-
ing the 5V and 1.8V outputs. The OUT output by virtue
of the MR pin, keeps the RST output low until the 1.8V
supply is ready.
–
IN rising threshold of 5.972V, the PMOS switch is turned
on. The LTC2960-2 also supervises V
to provide a low
OUT
batterysignalasanearlywarningofimpendingshutdown.
A 10k resistor is included in series with the V pin to limit
CC
current in the event of a reverse battery condition. In all
three examples, the load drops to <2.5μA typically and
excessive battery drain is prevented.
V
OUT
V
IN
V
OUT
LT3009-5
SHDN
IN
5V
16.4V
C2
1μF
16V
R3B
R4
10k
20mA MAX
118k*
Automotive Supervisor (LTC2960 H-Grade)
R3A
7.32M*
GND
The circuit in Figure 11 uses the LTC2960-3 (H-grade) as a
lowvoltagesupervisorcapableofoperatingintemperatures
upto125°Cinautomotiveenvironments.TheLT4356surge
V
CC
C1
0.1μF
50V
DV
CC
ADJ
stopper limits V to 27V under the alternator load dump
IN
R2
68k*
LTC2960-4
–
condition. The LT3991 buck regulator in conjunction with
the LTC2960 draw <10μA quiescent current for no load,
which limits the drain on the vehicle battery even after
long periods of inactivity.
IN
RST
FAULT
OUT
MR
R1
182k*
GND
2960 F12
Window Comparator for High Voltage Input
UPPER THRESHOLD = 16.897V
LOWER THRESHOLD = 12.3V
*VISHAY-DALE CRCW SERIES 0603 1%
The LTC2960-4 can be configured as a window compara-
tor to monitor high voltage supplies or battery stacks as
Figure 12. Window Comparator for High Voltage Input
shown in Figure 12. A fault signal is generated if V is out
IN
ofregulation. TheOUToutputoftheLTC2960-4isfedback
into the MR input to drive the RST output. A micropower
LDO provides bias to the active pull-up DV supply for
CC
low static current draw in the outputs.
2960f
14
Linear Systems [ Linear Systems ]
