LTC2917/LTC2918
Voltage Supervisor with
27 Selectable Thresholds
and Watchdog Timer
FEATURES DESCRIPTION
9 Selectable Supply Voltages
The LTC 2917-A/LTC2917-B and LTC2918-A/LTC2918-B
12V, 5V, 3.3V, 2.5V, 1.8V
are low voltage single-supply monitors with selectable
1.5V, 1.2V, 1V, +ADJ (0.5V)
thresholds and an adjustable watchdog timer. The parts
3 Selectable Tolerances
operate from 1.5V to 5.5V and consume a quiescent cur-
5%, 10%, 15% (LTC2917)
rent of only 30A.
Manual Reset Input (LTC2918)
Two three state inputs select one of nine internally pro-
1.5V to 5.5V Supply Operation
grammed thresholds without the need for external resistors.
Adjustable Watchdog Timeout
For the LTC2917, an additional three state input determines
Windowed Watchdog Timeout for Higher Reliability
the tolerance (5%, 10%, 15%). The tolerance for the
Applications (LTC2917-B, LTC2918-B)
LTC2918 is xed at 5%. Threshold accuracy is guaranteed
6.2V Shunt Regulator for High Voltage Operation
at 1.5% over the entire operating temperature range.
Guaranteed Operation to 125C
Glitch ltering ensures reliable reset operation without
Guaranteed Threshold Accuracy: 1.5%
false triggering.
Low Quiescent Current: 30A Typical
The reset timeout and the watchdog timeout may be set
Power Supply Glitch Immunity
with no external components, or adjusted using an exter-
Guaranteed RST for V 0.8V
CC
nal capacitor. A windowed watchdog feature is available
10-Lead MSOP Packages and (3mm 2mm) DFN
for high-reliability applications (B1 versions). A separate
Packages
manual reset input on the LTC2918-A/LTC2918-B allows
APPLICATIONS
a simple push button interface.
Handheld Devices
Operation to 125C makes the LTC2917-A/LTC2917-B
Cell Phone Base Stations
and LTC2918-A/LTC2918-B suitable for automotive
Automotive Control Systems
applications.
Network Servers
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Optical Networking Systems
TYPICAL APPLICATION
1.8V Supply Monitor with Manual
Monitor Selection Table
Reset and Internal Timers Selected
NOMINAL VOLTAGE SEL1 SEL2
1.8V
12V V V
CC CC
0.1F 10k
5V V Open
CC
V
CC
3.3V V GND
CC
LTC2918-A P 2.5V Open V
CC
VM RST RST
1.8V Open Open
RT WDI I/O
29178 TA01 1.5V Open GND
WT SEL1
MR SEL2
1.2V GND V
CC
GND
1V GND Open
t = 1.6s
WDU
t = 200ms
RST
ADJ (0.5V) GND GND
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1LTC2917/LTC2918
(Note 1, 2)
ABSOLUTE MAXIMUM RATINGS
Terminal Voltages Operating Temperature Range
V (Note 3) .......................................... 0.3V to 5.7V LTC2917C/LTC2918C ............................... 0C to 70C
CC
SEL1, SEL2, TOL, WDI, MR, RST ......... 0.3V to 7.5V LTC2917I/LTC2918I .............................. 40C to 85C
VM ......................................................... 0.3V to 15V LTC2917H/LTC2918H ......................... 40C to 125C
RT, WT .......................................0.3V to (V + 0.3)V Storage Temperature Range ................... 65C to 150C
CC
Terminal Currents Lead Temperature (Soldering, 10 sec)
V (Note 3) .......................................................5mA MSOP ...............................................................300C
CC
PIN CONFIGURATION
LTC2917 LTC2917
TOP VIEW
1 10
GND RST
TOP VIEW
2 9
TOL RT
GND 1 10 RST
TOL 2 9 RT
3 11 8
SEL2 WT
SEL2 3 8 WT
4 7
SEL1 WDI
SEL1 4 7 WDI
VM 5 6 V
5 6
CC VM V
CC
MS PACKAGE
DDB PACKAGE
10-LEAD PLASTIC MSOP
10-LEAD (3mm s 2mm) PLASTIC DFN
T = 125C, = 200C/W
JMAX JA
T = 125C, = 43C/W
JMAX JA
LTC2917
EXPOSED PAD (PIN 11) PCB GND
CONNECTION OPTIONAL
LTC2917
LTC2918 LTC2918 TOP VIEW
1 10
GND RST
TOP VIEW
2 9
MR RT
GND 1 10 RST
MR 2 9 RT
3 11 8
SEL2 WT
SEL2 3 8 WT
4 7
SEL1 WDI
SEL1 4 7 WDI
VM 5 6 V
5 6
CC VM V
CC
MS PACKAGE
DDB PACKAGE
10-LEAD PLASTIC MSOP
10-LEAD (3mm s 2mm) PLASTIC DFN
T = 125C, = 200C/W
JMAX JA
T = 125C, = 43C/W
JMAX JA
LTC2918
EXPOSED PAD (PIN 11) PCB GND
CONNECTION OPTIONAL
LTC2918
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2