LTC2901
Programmable Quad Supply
Monitor with Adjustable Reset
and Watchdog Timers
FEATURES
DESCRIPTIO
The LTC 2901 is a programmable supply monitor for
Simultaneously Monitors Four Supplies
systems with up to four supply voltages. One of 16 preset
16 User Selectable Combinations of 5V, 3.3V, 3V,
or adjustable voltage monitor combinations can be se-
2.5V, 1.8V, 1.5V and/or Adj Voltage Thresholds
lected using an external resistor divider connected to the
Guaranteed Threshold Accuracy: 1.5% of
program pin. The preset voltage thresholds are accurate
Monitored Voltage Over Temperature
to 1.5% over temperature. All four voltage comparator
Selectable Supply Tolerance: 5% and 10% Below
outputs are connected to separate pins for individual
Monitored Voltage (LTC2901-3/LTC2901-4)
supply monitoring.
Low Supply Current: 43A Typ
Adjustable Reset Time
The reset and watchdog delay times are adjustable using
Adjustable Watchdog Time
external capacitors. Tight voltage threshold accuracy and
Open-Drain RST Output (LTC2901-1/LTC2901-3)
glitch immunity ensure reliable reset operation without
Push-Pull RST Output (LTC2901-2/LTC2901-4)
false triggering. The RST output is guaranteed to be in the
Individual Nondelayed Monitor Output for Each Supply
correct state for V down to 1V. The LTC2901-1/
CC
Power Supply Glitch Immunity
LTC2901-3 features an open-drain RST output, while the
Guaranteed RST for V 1V
CC
LTC2901-2/LTC2901-4 has a push-pull RST output.
16-Lead Narrow SSOP Package
The 43A supply current makes the LTC2901 ideal for
U
power conscious systems and it may be configured to
APPLICATIO S
monitor less than four inputs. The parts are available in
Desktop and Notebook Computers
the 16-lead narrow SSOP package.
Multivoltage Systems
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Telecom Equipment
Patent Pending.
Portable Battery-Powered Equipment
Network Servers
TYPICAL APPLICATIO
Quadruple Supply Monitor (5V, 3.3V, 2.5V, 1.8V)
Quadruple Supply Monitor (5V, 3.3V, 2.5V, 1.8V) 10% Undervoltage Monitoring, Watchdog Asserts RST
5V 5V
3.3V 3.3V
DC/DC SYSTEM DC/DC SYSTEM
2.5V 2.5V
CONVERTER LOGIC CONVERTER LOGIC
1.8V 1.8V
R3 R3
POWER POWER
10k 10k
V3 V4 V3 V4
GOOD GOOD
V1 COMP1 V1 COMP1
COMP2 COMP2
LTC2901-2 LTC2901-4
V2 COMP3 V2 COMP3
C2 C2
COMP4 COMP4
0.1F 0.1F
C1
C1
V WDI V WDI
REF REF
0.1F
0.1F
WDO TOL 5V
R1 R1
59k V 59k V
RST RST
PG PG
2901 TA01 2901 TA01b
1% 1%
GND CRT CWT GND CRT CWT
R2 R2
t = 216ms t = 216ms
40.2k RST 40.2k RST
C C C C
RT WT RT WT
t = 940ms t = 940ms
WD WD
1% 47nF 47nF 1% 47nF 47nF
2901fb
1
U
ULTC2901
ABSOLUTE AXI U RATI GS (Notes 1, 2, 3)
V1, V2, V3, V4, V ..................................... 0.3V to 7V Operating Temperature Range
PG
RST (LTC2901-1/LTC2901-3) ..................... 0.3V to 7V LTC2901-1C/LTC2901-2C/
RST (LTC2901-2/LTC2901-4) ....... 0.3V to (V2 + 0.3V) LTC2901-3C/LTC2901-4C ....................... 0C to 70C
COMPX ....................................................... 0.3V to 7V LTC2901-1I/LTC2901-2I/
CWT, WDI, WDO ......................................... 0.3V to 7V LTC2901-3I/LTC2901-4I .................... 40C to 85C
V , CRT, TOL ............................ 0.3V to (V + 0.3V) Storage Temperature Range .................. 65C to 150C
CC
REF
Reference Load Current (I ) ............................ 1mA Lead Temperature (Soldering, 10 sec)................... 300C
VREF
V4 Input Current (ADJ Mode) ............................. 1mA
UUW
PACKAGE/ORDER I FOR ATIO
ORDER PART ORDER PART
TOP VIEW TOP VIEW
NUMBER NUMBER
COMP3 1 COMP2 COMP3 1 COMP2
16 16
LTC2901-1CGN LTC2901-3CGN
COMP1 2 COMP4 COMP1 2 COMP4
15 15
LTC2901-2CGN LTC2901-4CGN
V3 3 14 V2 V3 3 14 V2
LTC2901-1IGN LTC2901-3IGN
V1 4 13 V4 V1 4 13 V4
LTC2901-2IGN LTC2901-4IGN
CRT 5 12 V CRT 5 12 V
REF REF
RST 6 11 V RST 6 11 V
PG PG
GN16 PART MARKING GN16 PART MARKING
WDO 7 10 GND TOL 7 10 GND
WDI 8 9 CWT WDI 8 9 CWT
29013
29011
29014
29012
GN PACKAGE GN PACKAGE
16-LEAD PLASTIC SSOP 16-LEAD PLASTIC SSOP
29013I
29011I
T = 125C, = 110C/W T = 125C, = 110C/W
JMAX JA JMAX JA
29014I
29012I
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: