LTC2908CTS8-A1-TRMPBF [Linear]
Precision Six Input Supply Monitor; 精准六输入电源监视器型号: | LTC2908CTS8-A1-TRMPBF |
厂家: | Linear |
描述: | Precision Six Input Supply Monitor |
文件: | 总16页 (文件大小:195K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LTC2908
Precision
Six Input Supply Monitor
FEATURES
DESCRIPTION
The LTC®2908 is a six input supply monitor for systems
requiring a precise and compact monitoring solution for
multiple supply voltages. The inputs can be shorted to-
gether for monitoring systems with fewer than six supply
voltages, and the open drain RST output of two or more
LTC2908 can be wired-OR together for monitoring sys-
tems with more than six supply voltages. The common
reset output remains low until all six inputs have been in
compliance for 200ms.
n
Ultralow Voltage Reset: V = 0.5V Guaranteed*
CC
n
Monitors Six Inputs Simultaneously:
5V, 3.3V, 2.5V, 1.8V, ADJ1, ADJ2 (LTC2908-A1)
3.3V, 2.5V, 1.8V, 1.5V, ADJ1, ADJ2 (LTC2908-B1)
2.5V, ADJ1, ADJ2, ADJ3, ADJ4, ADJ5
(LTC2908-C1)
n
Guaranteed Threshold Accuracy: 1.5% of
Monitored Voltage Over Temperature
n
n
n
n
n
Internal V Auto Select
CC
Power Supply Glitch Immunity
The LTC2908 features a tight 1.5% threshold accuracy
over the entire operating temperature range and glitch
immunity to ensure reliable reset operation without false
triggering. Theopen-drainRSToutput state is guaranteed
to be in the correct state as long as V1 and/or V2 is 0.5V
or greater.
200ms Reset Time Delay
Active Low Open-Drain RST Output
Low Profile (1mm) 8-Lead SOT-23 (ThinSOT™) and
Plastic (3mm × 2mm) DFN Packages
APPLICATIONS
TheLTC2908alsofeaturesadjustableinputswithanominal
threshold level at 0.5V. This product provides a precise,
space-conscious, micropower and general purpose solu-
tion for any kind of system requiring supply monitors.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT
is a trademark of Linear Technology Corporation. All other trademarks are the property of
their respective owners. *Patent pending.
n
Network Servers
n
Wireless Base Stations
n
Optical Networking Systems
Multivoltage Systems
Desktop and Notebook Computers
n
n
TYPICAL APPLICATION
Six Supply Monitor with 5% Tolerance
(12V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V)
12V
RST Output Voltage vs V1
with 10k Pull-Up Resistor to V1
3.3V
2.5V
1.8V
DC/DC
DC/DC
DC/DC
DC/DC
DC/DC
0.4
V3 = V4 = V
=
ADJ1
=
V
ADJ2
V
ADJ4
= V
ADJ3
= V
ADJ5
= GND
0.3
0.2
0.1
0
SYSTEM
V1 INPUT
1.5V
1.2V
V2 = GND
0.1μF 0.1μF
2.15M
V
LTC2908-B1
GND
124k
V
100k
100k
V2 = V1 (A1/B1)
V1
V2 V3 V4
ADJ1
ADJ2
0.4
0
0.2
0.6
0.8
V1 (V)
RST
2908 TA01a
2908 TA01b
2908fc
1
LTC2908
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2)
Storage Temperature Range
Terminal Voltages
DFN Package......................................–65°C to 125°C
TSOT-23 Package...............................–65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
V1, V2, V3, V4 .........................................–0.3V to 7V
V
, V
, V
,..................–0.3V to (V + 0.6V)
ADJ1 ADJ2 ADJ3 CC
V
, V
.............................–0.3V to (V + 0.6V)
ADJ4 ADJ5 CC
RST.......................................................... –0.3V to 7V
Operating Temperature Range
LTC2908C ................................................ 0°C to 70°C
LTC2908I..............................................–40°C to 85°C
PIN CONFIGURATION
LTC2908CDDB-A1
LTC2908IDDB-A1
LTC2908CDDB-B1
LTC2908IDDB-B1
LTC2908CDDB-C1
LTC2908IDDB-C1
LTC2908CTS8-A1
LTC2908ITS8-A1
LTC2908CTS8-B1
LTC2908ITS8-B1
LTC2908CTS8-C1
LTC2908ITS8-C1
TOP VIEW
TOP VIEW
GND
RST
V4
1
2
3
4
8
7
6
5
V
GND
1
2
3
4
8
7
6
5
V
ADJ4
V
ADJ3
V
ADJ2
V
ADJ1
ADJ2
TOP VIEW
V2 1
TOP VIEW
V1 1
V3
V
RST
8 V1
7 V
8 V
7 V
ADJ1
ADJ2
9
9
V
ADJ1
ADJ5
V1
ADJ1
V4 2
RST 3
GND 4
V
2
ADJ5
V2
V1
6 V3
5 V
RST 3
GND 4
6 V
5 V
ADJ3
ADJ4
ADJ2
DDB8 PACKAGE
8-LEAD (3mm × 2mm) PLASTIC DFN
= 125°C, θ = 76°C/W
DDB8 PACKAGE
8-LEAD (3mm × 2mm) PLASTIC DFN
= 125°C, θ = 76°C/W
TS8 PACKAGE
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
8-LEAD PLASTIC TSOT-23
T
JMAX
T
JMAX
T
= 125°C, θ = 250°C/W
T
= 125°C, θ = 250°C/W
JA
JA
JMAX
JA
JMAX
JA
EXPOSED PAD (PIN 9)
(PCB CONNECTION OPTIONAL)
EXPOSED PAD (PIN 9)
(PCB CONNECTION OPTIONAL)
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI)
TAPE AND REEL
PART MARKING* PACKAGE DESCRIPTION
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
LTC2908CDDB-A1#TRMPBF
LTC2908IDDB-A1#TRMPBF
LTC2908CDDB-B1#TRMPBF
LTC2908IDDB-B1#TRMPBF
LTC2908CDDB-C1#TRMPBF
LTC2908IDDB-C1#TRMPBF
LTC2908CTS8-A1#TRMPBF
LTC2908ITS8-A1#TRMPBF
LTC2908CTS8-B1#TRMPBF
LTC2908ITS8-B1#TRMPBF
LTC2908CTS8-C1#TRMPBF
LTC2908ITS8-C1#TRMPBF
LTC2908CDDB-A1#TRMPBF
LTC2908IDDB-A1#TRMPBF
LTC2908CDDB-B1#TRMPBF
LTC2908IDDB-B1#TRMPBF
LTC2908CDDB-C1#TRMPBF
LTC2908IDDB-C1#TRMPBF
LTC2908CTS8-A1#TRMPBF
LTC2908ITS8-A1#TRMPBF
LTC2908CTS8-B1#TRMPBF
LTC2908ITS8-B1#TRMPBF
LTC2908CTS8-C1#TRMPBF
LTC2908ITS8-C1#TRMPBF
LBFD
LBFF
LBFG
LBFH
LCFV
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD (3mm × 2mm) PLASTIC DFN
8-LEAD PLASTIC TSOT-23
LCFV
LTBFJ
LTBFK
LTBFM
LTBFN
LTCFT
LTCFT
8-LEAD PLASTIC TSOT-23
8-LEAD PLASTIC TSOT-23
8-LEAD PLASTIC TSOT-23
8-LEAD PLASTIC TSOT-23
8-LEAD PLASTIC TSOT-23
–40°C to 85°C
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
2908fc
2
LTC2908
ELECTRICAL CHARACTERISTICS (LTC2908-A1) The ● denotes specifications which apply over the full
operating temperature range, otherwise specifications are TA = 25°C, VCC = 5V unless otherwise noted. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
4.750
3.135
2.375
1.710
0.508
UNITS
l
l
l
l
l
V
RT50
V
RT33
V
RT25
V
RT18
V
RTADJ
5V, 5% Reset Threshold
3.3V, 5% Reset Threshold
2.5V, 5% Reset Threshold
1.8V, 5% Reset Threshold
ADJ, 5% Reset Threshold
V1 Input Threshold
V2 Input Threshold
V3 Input Threshold
V4 Input Threshold
4.600
3.036
2.300
1.656
0.492
4.675
3.086
2.338
1.683
0.500
V
V
V
V
V
V
, V
Input Threshold
ADJ1 ADJ2
(LTC2908-B1) The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are
TA = 25°C, VCC = 3.3V unless otherwise noted. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
3.135
2.375
1.720
1.425
0.508
UNITS
l
l
l
l
l
V
RT33
V
RT25
V
RT18
V
RT15
V
RTADJ
3.3V, 5% Reset Threshold
2.5V, 5% Reset Threshold
1.8V, 5% Reset Threshold
1.5V, 5% Reset Threshold
ADJ, 5% Reset Threshold
V1 Input Threshold
V2 Input Threshold
V3 Input Threshold
V4 Input Threshold
3.036
2.300
1.656
1.380
0.492
3.086
2.338
1.683
1.403
0.500
V
V
V
V
V
V
, V
Input Threshold
ADJ1 ADJ2
(LTC2908-C1) The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are
TA = 25°C, VCC = 2.5V unless otherwise noted. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
l
l
V
2.5V, 5% Reset Threshold
ADJ, 5% Reset Threshold
V1 Input Threshold
2.300
2.338
2.375
V
RT25
V
V
, V
, V
, V
, V
,
RTADJ
ADJ1 ADJ2 ADJ3 ADJ4 ADJ5
Input Threshold
0.492
0.500
0.508
V
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. VCC = 5V
for the LT2908-A1, VCC = 3.3V for the LTC2908-B1or VCC = 2.5V for the LTC2908-C1, unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
l
V
Internal Supply Voltage
V1 Input Current (Note 4)
RST in Correct Logic State
0.5
6
V
CC
l
l
l
I
V1
V1 = 5.0V (LTC2908-A1)
V1 = 3.3V (LTC2908-B1)
V1 = 2.5V (LTC2908-C1)
26
24
22
70
70
70
μA
μA
μA
l
l
I
I
I
I
V2 Input Current (Note 4)
V3 Input Current
V2 = 3.3V (LTC2908-A1)
V2 = 2.5V (LTC2908-B1)
10
8
30
30
μA
μA
V2
l
l
V3 = 2.5V (LTC2908-A1)
V3 = 1.8V (LTC2908-B1)
2
2
5
5
μA
μA
V3
l
l
V4 Input Current
V4 = 1.8V (LTC2908-A1)
V4 = 1.5V (LTC2908-B1)
2
2
5
5
μA
μA
V4
l
V
, V
V
V
V
V
= V
= V
= V
= V =
ADJ5
15
nA
VADJ
ADJ1 ADJ2, ADJ3, ADJ4, ADJ5
ADJ1
ADJ2
ADJ3
ADJ4
Input Current
0.55V
2908fc
3
LTC2908
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. VCC = 5V
for the LT2908-A1, VCC = 3.3V for the LTC2908-B1 or VCC = 2.5V for the LTC2908-C1, unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
200
250
MAX
UNITS
ms
l
t
t
Reset Time-Out Period
160
260
RST
V Undervoltage Detect to RST
X
V Less Than Reset Threshold V
by
μs
UV
X
RTX
More Than 1%
l
l
l
V
V
Output Voltage High RST (Note 5)
Output Voltage Low RST
I
I
I
= –1μA, V = 5V (LTC2908-A1)
V
CC
V
CC
V
CC
– 1.5
– 1.0
– 1.0
V
V
V
OH
OL
RST
RST
RST
CC
= –1μA, V = 3.3V (LTC2908-B1)
CC
= –1μA, V = 2.5V (LTC2908-C1)
CC
l
l
l
V
V
V
= 0.5V, I
= 1.0V, I
= 3.0V, I
= 5μA
= 100μA
= 2500μA
0.01
0.01
0.10
0.15
0.15
0.30
V
V
V
CC
CC
CC
RST
RST
RST
Note 3: All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 4: Under typical operating conditions, most of the quiescent cur-
rent is drawn from the V1 input. When V2 exceeds V1, V2 supplies most
of the quiescent current.
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliabilty and lifetime.
Note 2: The greater of V1, V2 is the internal supply voltage (V ) for the
CC
LTC2908-A1 and the LTC2908-B1. V1 is the internal supply voltage (V
for the LTC2908-C1.
)
Note 5: The output pin RST has an internal pull-up to V of typically
6μA. However, an external pull-up resistor may be used when a faster
CC
CC
rise time is required or for V voltages greater than V
.
OH
CC
TYPICAL PERFORMANCE CHARACTERISTICS
Specifications are at TA = 25°C unless otherwise noted.
5V Threshold Voltage
vs Temperature
3.3V Threshold Voltage
vs Temperature
2.5V Threshold Voltage
vs Temperature
3.135
3.115
3.095
3.075
3.055
3.035
4.750
4.725
4.700
4.675
4.650
4.625
4.600
2.375
2.360
2.345
2.330
2.315
2.300
50
TEMPERATURE (°C)
100
–50 –25
0
25
75
50
TEMPERATURE (°C)
100
50
TEMPERATURE (°C)
100
–50 –25
0
25
75
–50 –25
0
25
75
2908 G02
2908 G01
2908 G03
2908fc
4
LTC2908
TYPICAL PERFORMANCE CHARACTERISTICS
Specifications are at TA = 25°C unless otherwise noted.
1.8V Threshold Voltage
vs Temperature
1.5V Threshold Voltage
vs Temperature
ADJ Threshold Voltage
vs Temperature
1.710
1.700
1.690
1.680
1.670
1.660
1.425
1.420
1.415
1.410
1.405
1.400
1.395
1.390
1.385
1.380
0.5080
0.5060
0.5040
0.5020
0.5000
0.4980
0.4960
0.4940
0.4920
50
TEMPERATURE (°C)
100
–50 –25
0
25
75
–25
0
50
–50
75
100
25
–50
–25
0
25
100
50
75
TEMPERATURE (°C)
TEMPERATURE (°C)
2908 G04
2908 G06
2908 G05
IV1 vs Temperature
IV2 vs Temperature
IV3 vs Temperature
33
31
29
27
25
23
21
19
17
14
2.2
2.1
2.0
1.9
V1 = 5.0V (A1)/V1 = 3.3V (B1)/V1 = 2.5V (C1)
V2 = 3.3V (A1)/V2 = 2.5V (B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V1 = 1.5V (B1)
V1 = 5.0V (A1)/V1 = 3.3V (B1)
V1 = 5.0V (A1)/V1 = 3.3V (B1)
V2 = 3.3V (A1)/V2 = 2.5V (B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V4 = 1.5V (B1)
13 V2 = 3.3V (A1)/V2 = 2.5V (B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
12
V4 = 1.8V (A1)/V4 = 1.5V (B1)
V
V
= V
= V
=
V
= V
= 0.55V
V
= V
= 0.55V
ADJ1
ADJ4
ADJ2
ADJ5
ADJ3
ADJ1
ADJ2
ADJ1
ADJ2
11
10
9
=V
= 0.55V
A1
B1
A1
B1
1.8
1.7
8
C1
7
1.6
1.5
1.4
6
5
4
–50
0
25
50
75
100
–25
–25
0
50
–25
0
50
–50
75
100
–50
75
100
25
25
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
2908 G07
2908 G08
2908 G09
Typical Transient Duration
vs Comparator Overdrive
Reset Time-Out Period (tRST
)
IV4 vs Temperature
vs Temperature
700
600
500
400
300
200
100
0
2.2
2.1
2.0
1.9
250
240
230
220
210
200
190
180
170
160
150
T
= 25°C
A
V1 = 5.0V (A1)/V1 = 3.3V (B1)
V2 = 3.3V (A1)/V2 = 2.5V (B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V4 = 1.5V (B1)
RESET OCCURS
ABOVE CURVE
V
= V
= 0.55V
ADJ1
ADJ2
1.8
1.7
1.6
1.5
1.4
0.1
1
10
100
–25
0
50
–25
0
50
–50
75
100
–50
75
100
25
25
COMPARATOR OVERDRIVE VOLTAGE (% OF V
)
TEMPERATURE (°C)
TEMPERATURE (°C)
RTX
2908 G11
2908 G10
2908 G12
2908fc
5
LTC2908
TYPICAL PERFORMANCE CHARACTERISTICS
Specifications are at TA = 25°C unless otherwise noted.
RST Pull-Down Current vs
Supply Voltage
LTC2908-A1/LTC2908-B1
RST Output Voltage vs V1 with
RST Output Voltage vs V1 with
10k Pull-Up Resistor to V1
10k Pull-Up Resistor to V1
5.0
4.0
3.0
2.0
1.0
0
0.4
0.3
0.2
0.1
0
6
5
4
3
2
1
0
V3 = V4 = V
=
V1 = V2 (A1/B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V4 = 1.5V (B1)
V
= V1 = V2
ADJ1
CC
V
ADJ1
ADJ4
= GND (A1/B1)
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V4 = 1.5V (B1)
ADJ2
= V
V
= V
=
ADJ2
ADJ3
V
= V
= GND (C1)
ADJ5
V
V
= V
= V
= V
= 0.55V
=
V
ADJ1
= V
ADJ2
= 0.55V
ADJ1
ADJ4
ADJ2
ADJ5
ADJ3
RST AT
V1 = INPUT
150mV
V
RT33
LTC2908-B1
V2 = GND
RST AT
50mV
V
RT50
V2 = V1
V
V
RT50
RT25
V
RT33
LTC2908-C1
LTC2908-A1
LTC2908-B1 LTC2908-A1
0.4
V1 (V)
0
0.2
0.6
0.8
0
1
2
3
4
5
0
1
2
3
4
5
V1 (V)
SUPPLY VOLTAGE, V (V)
CC
2908 G14
2908 G13
2908 G15
RST Pull-Down Current vs
Supply Voltage
LTC2908-C1
RST Pull-Down Current vs
Supply Voltage with 2 Inputs
LTC2908-A1/LTC29089-B1
RST Pull-Down Current vs
Supply Voltage with 1 Input
10
1
10
1
4.0
3.5
3.0
2.5
V
= V1 = V2
V
= V1
CC
V
V
V
= V1
= V
CC
CC
ADJ1
ADJ4
RST AT 150mV
V3 = V4 = V
= V
= GND
V2 = V3 = V4 = V
= V
=
ADJ2
= V =
ADJ3
= 0.55V
ADJ1
ADJ2
ADJ1
ADJ2
ADJ5
V
= V
= V
= GND
ADJ5
= V
ADJ3
ADJ4
RST AT 150mV
RST AT 150mV
0.1
0.01
0.1
0.01
2.0
1.5
RST AT 50mV
RST AT 50mV
RST AT 50mV
1.0
0.5
0
V
RT25
LTC2908-C1
0.001
0.001
0.5
1.0
2.0
0
2.5
1.5
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
SUPPLY VOLTAGE V (V)
SUPPLY VOLTAGE, V (V)
SUPPLY VOLTAGE, V (V)
CC
CC
CC
2908 G16
2908 G17
2928 G25
RST Output Voltage Low vs
RST Pull-Down Current
LTC2908-A1
RST Output Voltage Low vs
RST Pull-Down Current
LTC2908-B1
RST Output Voltage Low vs
RST Pull-Down Current
LTC2908-C1
0.8
0.8
1.20
1.0
V1 = 5.0V
V2 = 3.3V
V3 = 2.5V
V4 = 1.8V
V1 = 3.3V
V2 = 2.5V
V3 = 1.8V
V4 = 1.5V
V1 = 2.5V
85°C
25°C
V
V
= V
= V
= V
=
ADJ3
ADJ1
ADJ4
ADJ2
ADJ5
0.7
0.6
0.7
0.6
= 0.4V
V
= V
ADJ2
= 0.4V
V
= V
= 0.4V
ADJ2
ADJ1
ADJ1
0.80
0.60
0.5
0.4
0.3
0.2
0.1
0.5
0.4
0.3
0.2
0.1
85°C
–40°C
25°C
85°C
–40°C
25°C
–40°C
0.40
0.20
0.00
0
0
5
10
20
25
30
35
5
10
20
(mA)
25
0
15
0
15
0.0
5.0 20.0
RST PULL-DOWN CURRENT, I (mA)
RST
10.0
15.0
25.0
RST PULL-DOWN CURRENT, I
(mA)
RST PULL-DOWN CURRENT, I
RST
RST
2908 G23
2908 G18
2908 G19
2908fc
6
LTC2908
TYPICAL PERFORMANCE CHARACTERISTICS
Specifications are at TA = 25°C unless otherwise noted.
RST Output Voltage High vs
RST Output Source Current
LTC2908-A1
RST Pull-Up Current vs
Supply Voltage
–30
5
4
3
2
1
V
= V1 = V2 (A1/B1), V = V1(C1)
CC
CC
V3 = 2.5V (A1)/V3 = 1.8V (B1)
V4 = 1.8V (A1)/V4 = 1.5V (B1)
–25
–20
–15
V
V
V
= V
= V
= 0.55V (A1/B1)
ADJ3
ADJ1
ADJ1
ADJ5
ADJ2
ADJ2
= V
= V
=
ADJ4
= 0.55V(C1)
RST HELD AT 0V
V
RT25
LTC2908-C1
25°C
V
–10
–5
0
RT33
LTC2908-B1
–40°C
85°C
V1 = 5.0V
V2 = 3.3V
V3 = 2.5V
V4 = 1.8V
V
RT50
LTC2908-A1
V
= V
= 0.55V
ADJ2
ADJ1
1.5
2
2.5
3
3.5
4
4.5
5
0
–4
–8
–12
–16
(μA)
–20
SUPPLY VOLTAGE, V (V)
OUTPUT SOURCE CURRENT, I
RST
CC
2908 G20
2908 G21
RST Output Voltage High vs
RST Output Source Current
LTC2908-B1
RST Output Voltage High vs
RST Output Source Current
LTC2908-C1
3.0
2.5
2.0
1.5
2.0
1.5
1.0
0.5
85°C
25°C
85°C
V1 = 3.3V
V2 = 2.5V
V3 = 1.8V
V4 = 1.5V
–40°C
1.0
0.5
–40°C
V1 = 2.5V
V
V
= V
= V
= V
ADJ3
= 0.55V
=
ADJ1
ADJ4
ADJ2
ADJ5
V
= V
= 0.55V
ADJ1
ADJ2
–4
OUTPUT SOURCE CURRENT, I
25°C
0
–6
–8
–10
(μA)
–12
–2
0
–1 –2 –3 –4 –5 –6 –7 –8
OUTPUT SOURCE CURRENT, I (μA)
RST
RST
2908 G22
2908 G24
(TS8 Package/DDB8 Package) LTC2908-A1/LTC2908-B1
PIN FUNCTIONS
V2 (Pin 1/Pin 4): Voltage Input 2. The greater of V1, V2 is
V
(Pin5/Pin8):AdjustableVoltageInput2.SeeTable 1
ADJ2
also the internal V . The operating voltage on this pin shall
for recommended ADJ resistors values.
CC
notexceed6V. Wheninnormaloperation(V1>V2), thispin
draws approximately 8μA. When this pin is acting as the
CC
V3 (Pin 6/Pin 7): Voltage Input 3.
V
ADJ1
(Pin7/Pin6):AdjustableVoltageInput1.SeeTable 1
V
(V2 > V1), this pin draws an additional 16μA. Bypass
for recommended ADJ resistors values.
this pin to ground with a 0.1μF (or greater) capacitor.
V1 (Pin 8/Pin 5): Voltage Input 1. The greater of V1, V2 is
V4 (Pin 2/Pin 3): Voltage Input 4.
also the internal V . The operating voltage on this pin shall
CC
RST (Pin 3/Pin 2): Reset Logic Output. Pulls low when
any voltage input is below the reset threshold and is held
low for 200ms after all voltage inputs are above threshold.
not exceed 6V. When in normal operation (V1 > V2), this pin
draws approximately 26 μA. When this pin is not acting as
theV (V2>V1),thispindrawsapproximately8μA.Bypass
CC
Thispinhasaweakpull-uptoV andmaybepulledabove
CC
this pin to ground with a 0.1μF (or greater) capacitor.
V
CC
using an external pull-up.
Exposed Pad (Pin 9, DDB8 Only): Exposed Pad may be
GND (Pin 4/Pin 1): Device Ground.
left open or connected to device ground.
2908fc
7
LTC2908
(TS8 Package/DDB8 Package) LTC2908-C1
PIN FUNCTIONS
GND (Pin 4/Pin 1): Device Ground.
(Pin 5/Pin 8): Adjustable Voltage Input 4.
V1 (Pin 1/Pin 4): Voltage Input 1. V1 is the internal V .
CC
The operating voltage on this pin shall not exceed 6V.
When in normal operation, this pin draws approximately
22μA. Bypass this pin to ground with a 0.1μF (or greater)
capacitor.
V
ADJ4
See Table 1 for recommended ADJ resistors values.
V
(Pin 6/Pin 7): Adjustable Voltage Input 3.
ADJ3
See Table 1 for recommended ADJ resistors values.
V
(Pin 2/Pin 3): Adjustable Voltage Input 5. See Table 1
ADJ5
V
(Pin 7/Pin 6): Adjustable Voltage Input 2.
for recommended ADJ resistors values.
ADJ2
See Table 1 for recommended ADJ resistors values.
RST (Pin 3/Pin 4): Reset Logic Output. Pulls low when
any voltage input is below the reset threshold and is held
low for 200ms after all voltage inputs are above threshold.
Thispinhasaweakpull-uptoVccandmaybepulledabove
Vcc using an external pull-up.
V
(Pin 8/Pin 5): Adjustable Voltage Input 1.
ADJ1
See Table 1 for recommended ADJ resistors values.
Exposed Pad (Pin 9, DDB8 Only): Exposed Pad may be
left open or connected to device ground.
BLOCK DIAGRAMS
LTC2908-A1/LTC2908-B1
V1
V2
V3
–
+
C1
C2
C3
C4
C5
POWER
DETECT
V
CC
–
+
V
CC
–
+
6μA
RST
200ms
RESET PULSE
GENERATOR
–
+
V4
V
–
+
ADJ1
V
–
+
ADJ2
C6
GND
BANDGAP
REFERENCE
2908 BD
2908fc
8
LTC2908
BLOCK DIAGRAMS
LTC2908-C1
V1
–
+
C1
C2
C3
C4
C5
V
–
+
ADJ1
V1
V
–
+
ADJ2
6μA
RST
200ms
RESET PULSE
GENERATOR
V
–
+
ADJ3
V
–
+
ADJ4
V
–
+
ADJ5
C6
GND
BANDGAP
REFERENCE
2908 BDa
TIMING DIAGRAM
VX Monitor Timing
V
RTX
V
X
t
t
RST
UV
1V
RST
2908 TD
2908fc
9
LTC2908
APPLICATIONS INFORMATION
Such an indeterminate voltage may trigger external logic
causing erroneous reset operation(s). Furthermore, a
mid-scale voltage level could cause external circuits to
operate in the middle of their voltage transfer character-
istic, consuming more quiescent current than normal.
These conditions could cause serious system reliability
problems.
Supply Monitoring
The LTC2908 is a low power, high accuracy, six input
supply monitoring circuit with two adjustable inputs. The
reset delay is set to a nominal of 200ms with an internal
capacitor, eliminating the need for an external timing
capacitor.
Allinputvoltagesmustbeabovepredeterminedthresholds
for the reset not to be invoked. The LTC2908 asserts the
reset output during power-up, power-down and brownout
conditions on any one of the voltage inputs.
Power-Up
During power-up, RST starts asserting low as soon as
there is at least 200mV on V1 and/or V2. The RST pull-
down capability is a function of V1 and V2 as shown in
the Typical Performance Characteristics.
Ultralow Voltage Pull-Down on RST
The LTC2908 issues a logic low on the RST output when
any one of the inputs falls below its threshold. Ideally, the
RST logic output would remain low with the input supply
voltage down to zero volts. Most supervisors lack pull-
down capability below 1V.
The greater of V1, V2 is the internal supply voltage (V )
CC
that powers the other internal circuitry. Once all the V
X
inputs rise above their thresholds, an internal timer is
started. After the internal timer counts a 200ms delay
time, RST weakly pulls high to V .
CC
The LTC2908 power supply supervisor incorporates a
novel low voltage pull-down circuit that can hold the RST
line low with as little as 200mV of input supply voltage on
V1 and/or V2 (see Figures 1 and 2). The pull-down circuit
helps maintain a low impedance path to ground, reducing
the risk of the RST node from floating to an indeterminate
voltage.
Power-Down
On power-down, once any of the V inputs drop below
X
their threshold, RST asserts logic low. V of at least 0.5V
CC
guarantees a logic low of 0.15V at RST.
10
10
V
= V1 = V2
V
= V1
CC
CC
V3 = V4 = V
= V
ADJ2
= GND
V2 = V3 = V4 = V
= V
ADJ5
=
ADJ1
ADJ1
ADJ2
V
= V
= V
= GND
ADJ3
ADJ4
1
0.1
1
0.1
RST AT 150mV
RST AT 150mV
RST AT 50mV
RST AT 50mV
0.01
0.001
0.01
0.001
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
SUPPLY VOLTAGE, V (V)
SUPPLY VOLTAGE, V (V)
CC
CC
2908 G16
2908 G17
Figure 1.RST Pull-Down Current vs
Supply Voltage with 2 Inputs LTC2908-A1/
LTC2908-B1
Figure 2.RST Pull-Down Current vs
Supply Voltage with 1 Input
2908fc
10
LTC2908
APPLICATIONS INFORMATION
Adjustable Input
In an application with less than six supply voltages, the
unused supervisor inputs should be tied to the closest
higher supply voltage available.
The noninverting input on the V
comparator is set to
ADJ
0.5V. And the high impedance inverting input directly ties
to the V pin.
ADJ
Threshold Accuracy
In a typical application, this pin connects to a tap point
on an external resistive divider between the positive
voltage being monitored and ground (see Figure 3). The
following formula derives the value of the R1 resistor in
the divider from a particular value of R2 and the desired
trip voltage:
Specifyingsystemvoltagemarginforworst-caseoperation
requires the consideration of three factors: power supply
tolerance,ICsupplyvoltagetoleranceandsupervisorreset
threshold accuracy. Highly accurate supervisors ease the
design challenge by decreasing the overall voltage margin
required for reliable system operation. Consider a 5V
system with a 5% power supply tolerance band.
ꢀ
ꢃ
VTRIP
0.5V
R1=
–1 R2
ꢅ
ꢂ
ꢁ
ꢄ
System ICs powered by this supply must operate reliably
within this band (and a little more, as explained below).
The bottom of the supply tolerance band, at 4.75V (5%
below 5V), is the exact voltage at which a perfectly ac-
curate supervisor generates a reset (see Figure 4). Such
a perfectly accurate supervisor does not exist—the
actual reset threshold may vary over a specified band
( 1.5% for the LTC2908 supervisors). Figure 5 shows
the typical relative threshold accuracy for all six inputs
over temperature.
R2 = 100k is recommended. Table 1 shows suggested
1% resistor values for various adjustable applications and
their corresponding trip thresholds.
Table 1. Suggested 1% Resistor Values for the VADJ Inputs
V
(V)
V
(V)
R1 (kΩ)
2150
1780
1400
1300
1020
845
511
464
365
237
R2 (kΩ)
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
SUPPLY
TRIP
12
11.25
9.4
10
8
7.5
6
5
3.3
3
2.5
1.8
1.5
1.2
1.0
0.9
0.8
0.7
0.6
7.5
7
5.6
NOMINAL
SUPPLY
VOLTAGE
5.000V
4.725
3.055
2.82
MINIMUM
SUPPLY
IDEAL
RELIABLE TOLERANCE SUPERVISOR
SYSTEM
VOLTAGE
THRESHOLD
4.750V
4.675V
4.600V
–5.0%
–6.5%
1.5%
THRESHOLD
BAND
2.325
1.685
1.410
1.120
0.933
0.840
0.750
0.655
0.561
2.5%
THRESHOLD
BAND
–8.0%
REGION OF POTENTIAL MALFUNCTION
WITH 2.5% MONITOR
182
124
4.500V
–10%
2908 F04
86.6
68.1
49.9
30.9
12.1
Figure 4. Threshold Band Diagram
1.5
1.0
V
0.5
TRIP
LTC2908-A1/LTC2908-B1/LTC2908-C1
R1
1%
0
V
ADJ
–
R2
1%
–0.5
–1.0
–1.5
+
+
0.5V
–
–50
0
25
50
75
100
–25
TEMPERATURE (°C)
2908 F05
2908 F03
Figure 3. Setting the Adjustable Trip Point
Figure 5. Typical Threshold Accuracy vs Temperature
2908fc
11
LTC2908
APPLICATIONS INFORMATION
With this variation of reset threshold in mind, the nomi-
nal reset threshold of the supervisor resides below the
minimum supply voltage; just enough so that the reset
threshold band and the power supply tolerance bands
do not overlap. If the two bands overlap, the supervisor
could generate a false or nuisance reset when the power
supply remains within its specified tolerance band (for
example at 4.8V).
Therefore,theLTC2908takesadifferentapproachtosolv-
ing this problem of supply noise causing spurious reset.
The first line of defense against this spurious reset is a
first order lowpass filter at the output of the comparators.
Therefore, each comparator output is integrated over time
before triggering the output logic. Therefore, any kind of
transient at the input of the comparator needs to be of
sufficient magnitude and duration before it can trigger a
change in the output logic.
Adding half of the reset threshold accuracy spread (1.5%)
to the ideal 5% thresholds puts the LTC2908 thresholds at
6.5% (typ) below the nominal input voltage. For example,
the 5V typical threshold is 4.675V, or 75mV below the
ideal threshold of 4.750V. The guaranteed threshold lies
in the band between 4.600V (8% below 5V) and 4.750V
(5% below 5V) over temperature.
The second line of defense is the 200ms delay time t
.
RST
Thisdelayeliminatestheeffectofanysupplynoise,whose
frequency is above 1/200ms = 5Hz, on the RST output.
When any one of the supply voltages drops below its
threshold, the RST pin asserts low. When the supply
recovers above its threshold, the reset-pulse-generator
timer starts counting.
Thepoweredsystemmustworkreliablydowntothelowest
voltage in the threshold band or risk malfunction before
the reset line falls. In the 5V example, using the 1.5%
accurate supervisor, the system ICs must work down to
4.60V (8% below 5V). System ICs working with a 2.5%
accurate supervisor must operate down to 4.50V (10%
below 5V), increasing the required system voltage margin
and the probability of system malfunction.
Ifallthesuppliesremainabovetheircorrespondingthresh-
old when the timer finishes counting, the RST pin weakly
pulls high. However, if any of the supplies falls below its
threshold any time during the period when the timer is still
counting, the timer resets and it starts fresh when all the
supplies rise above their corresponding threshold.
Note that this second line of defense is only effective
for a rising supply and does not affect the sensitivity of
the system to a falling supply. Therefore, the first line of
defense that works for both cases of rising and falling is
necessary. These two approaches prevent spurious reset
caused by supply noise without sacrificing the threshold
accuracy.
In any supervisory application, supply noise riding on
the monitored DC voltage can cause spurious resets,
particularly when the monitored voltage is near the reset
threshold. A less desirable but common solution to this
problem is to introduce hysteresis around the nominal
threshold. Notice however, this hysteresis introduces an
error term in the threshold accuracy. Therefore, a 2.5%
accurate monitor with 1% hysteresis is equivalent to a
3.5% monitor with no hysteresis.
Although all six comparators for the six inputs have built-
in glitch filtering, use bypass capacitors on the V1 and
V2 inputs because the greater of V1 or V2 supplies the
V
for the part (a 0.1μF ceramic capacitor satisfies most
CC
applications). Apply filter capacitors on the V3, V4, V
,
ADJ1
V
, V
, V
and V
inputs in extremely noisy
ADJ2 ADJ3 ADJ4
ADJ5
situations.
2908fc
12
LTC2908
APPLICATIONS INFORMATION
RST Output Characteristics
transistor estimated to be typically 40Ω at room tempera-
ture (25°C) and C
is the external load capacitance on
LOAD
The DC characteristics of the RST pull-up and pull-down
strength are shown in the Typical Performance Character-
istics section. The RST output has a weak internal pull-up
the pin. Assuming a 150pF load capacitance, the fall time
is about 13ns.
to V = Max(V1, V2) and a strong pull-down to ground.
The rise time on the RST pin is limited by a weak internal
CC
pull-up current source to V . The following formula esti-
CC
The weak pull-up and strong pull-down arrangement al-
lowsthispintohaveopen-drainbehaviorwhilepossessing
several other beneficial characteristics.
mates the output rise time (10% to 90%) at the RST pin:
t
≈ 2.2 • R • C
PU LOAD
RISE
The weak pull-up eliminates the need for external pull-up where R is the on-resistance of the pull-up transis-
PU
resistors when the rise time on these pins is not critical. tor. Notice that this pull-up transistor is modeled as a
On the other hand, the open-drain RST behavior allows for 6μA current source in the Block Diagram as a typical
wired-OR connections and can be useful when more than representation.
one signal needs to pull down on the RST line.
The on-resistance as a function of the V = Max(V1, V2)
CC
As noted in the discussion of power-up and power-down, voltage (for V > 1V) at room temperature is estimated
CC
thecircuitsthatdriveRSTarepoweredbyVCC.Duringfault as follows:
6 •105
condition, VCC of at least 0.5V guarantees a maximum
RPU =
Ω
VOL = 0.15V at RST
.
MAX V1,V2 –1V
At V = 3.3V, R is about 260k. Using 150pF for load
Output Rise and Fall Time Estimation
CC
PU
capacitance, the rise time is 86μs. A smaller external
pull-up resistor may be used if the output needs to pull
up faster and/or to a higher voltage. For example, the rise
time reduces to 3.3μs for a 150pF load capacitance when
using a 10k pull-up resistor.
Thefollowingformulaestimatestheoutputfalltime(90%to
10%) for a particular external load capacitance (C
):
LOAD
t
≈ 2.2 • R • C
PD LOAD
FALL
where R is the on-resistance of the internal pull-down
PD
TYPICAL APPLICATIONS
Six Supply Monitor, 5% Tolerance, 12V, 5V, 3.3V, 2.5V, 1.8V, 1V
12V
5V
DC/DC
DC/DC
DC/DC
DC/DC
DC/DC
3.3V
2.5V
SYSTEM
1.8V
1.0V
C1
C2
0.1μF 0.1μF
R1
2.15M
R3
86.6k
R2
100k
R4
100k
V1
V2 V3 V4
V
V
ADJ2
ADJ1
LTC2908-A1
GND
RST
2908 TA02
2908fc
13
LTC2908
TYPICAL APPLICATIONS
Quad Supply Monitor with One Adjustable Input, 5% Tolerance, 3.3V, 2.5V, 1.8V, 1.2V
3.3V
2.5V
1.8V
1.2V
DC/DC
DC/DC
DC/DC
SYSTEM
C1
C2
0.1μF 0.1μF
R3
124k
R4
100k
V1
V2
V3 V4
LTC2908-B1
GND
V
V
ADJ1
ADJ2
RST
2908 TA03
Pin Programmable Dual Supply Monitor with Possible Future Expansion up to Six Supplies, 5% Tolerance, 3.3V and 2.5V
3.3V
SYSTEM
2.5V
DC/DC
C1
0.1μF
C2
0.1μF
V1
V2 V3 V4
LTC2908-B1
GND
V
V
ADJ1 ADJ2
RST
2908 TA05
Six Supply Monitor, 5% Tolerance 12V, 2.5V, 1.8V, 1.5V, 1.2V, 1.0V
12V
2.5V
DC/DC
1.8V
1.5V
DC/DC
DC/DC
DC/DC
DC/DC
SYSTEM
1.2V
1.0V
C1
0.1μF
R1
2.15M
R3
237k
R5
182k
R7
124k
R9
86.6k
R2
100k
R4
100k
R6
100k
R8
100k
R10
100k
V1
V
ADJ1
V
V
ADJ3
V
V
ADJ5
ADJ2
ADJ4
LTC2908-C1
GND
RST
2908 TA06
2908fc
14
LTC2908
PACKAGE DESCRIPTION
DDB Package
8-Lead Plastic DFN (3mm × 2mm)
(Reference LTC DWG # 05-08-1702 Rev B)
0.61 ±0.05
(2 SIDES)
R = 0.115
0.40 ± 0.10
3.00 ±0.10
(2 SIDES)
TYP
5
R = 0.05
TYP
8
0.70 ±0.05
2.55 ±0.05
1.15 ±0.05
2.00 ±0.10
PIN 1 BAR
TOP MARK
PIN 1
(2 SIDES)
R = 0.20 OR
0.25 × 45°
CHAMFER
(SEE NOTE 6)
PACKAGE
OUTLINE
0.56 ± 0.05
(2 SIDES)
4
1
(DDB8) DFN 0905 REV
B
0.25 ± 0.05
0.25 ± 0.05
0.75 ±0.05
0.200 REF
0.50 BSC
2.20 ±0.05
(2 SIDES)
0.50 BSC
2.15 ±0.05
(2 SIDES)
0 – 0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING CONFORMS TO VERSION (WECD-1) IN JEDEC PACKAGE OUTLINE M0-229
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
TS8 Package
8-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1637)
2.90 BSC
(NOTE 4)
0.52
MAX
0.65
REF
1.22 REF
1.50 – 1.75
(NOTE 4)
2.80 BSC
1.4 MIN
3.85 MAX 2.62 REF
PIN ONE ID
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.22 – 0.36
8 PLCS (NOTE 3)
0.65 BSC
0.80 – 0.90
0.20 BSC
DATUM ‘A’
0.01 – 0.10
1.00 MAX
0.30 – 0.50 REF
1.95 BSC
0.09 – 0.20
(NOTE 3)
TS8 TSOT-23 0802
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
2908fc
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However,noresponsibilityisassumedforitsuse.LinearTechnologyCorporationmakesnorepresenta-
t ion t h a t t he in ter c onne c t ion o f i t s cir cui t s a s de s cr ib e d her ein w ill no t in fr inge on ex is t ing p a ten t r igh t s.
15
LTC2908
TYPICAL APPLICATION
Six Supply Monitor with Manual Reset Button, 5% Tolerance, 12V, 5V, 3.3V, 2.5V, 1.8V, 1.5V
12V (V
TRIP
= 11.25V)
5V (V
TRIP
= 4.675V)
DC/DC
3.3V (V
2.5V (V
= 3.086V)
= 2.338V)
TRIP
DC/DC
DC/DC
DC/DC
DC/DC
SYSTEM
TRIP
1.8V (V
1.5V (V
= 1.685V)
= 1.410V)
TRIP
TRIP
C1
C2
R1
182k
R3
R2
100k
MANUAL
0.1μF 0.1μF
2.15M
RESET BUTTON
(NORMALLY OPEN)
R5*
10k
R4
100k
V1
V2 V3 V4
V
V
ADJ1
ADJ2
RST
LTC2908-A1
GND
*OPTIONAL RESISTOR RECOMMENDED
TO EXTEND ESD TOLERANCE
2908 TA04
RELATED PARTS
PART NUMBER
LTC690
DESCRIPTION
COMMENTS
5V Supply Monitor, Watchdog Timer and Battery Backup
3.3V Supply Monitor, Watchdog Timer and Battery Backup
5V Supply Monitor and Watchdog Timer
4.65 Threshold
2.9V Threshold
4.65 Threshold
4.37V/4.62V Threshold
LTC694-3.3
LTC699
LTC1232
5V Supply Monitor, Watchdog Timer and Pushbutton Reset
LTC1326/LTC1326-2.5
LTC1536
Micropower Precision Triple Supply Monitor for 5V/2.5V, 3.3V and ADJ 4.725V, 3.118V, 1V Threshold ( 0.75%)and ADJ
Precision Triple Supply Monitor for PCI Applications Meets PCI t Timing Specifications
FAIL
LTC1726-2.5/LTC1726-5 Micropower Triple Supply Monitor for 2.5V/5V, 3.3V and ADJ
LTC1727-2.5/LTC1727-5 Micropower Triple Supply Monitor with Open-Drain Reset
LTC1728-1.8/LTC1728-3.3 Micropower Triple Supply Monitor with Open-Drain Reset
LTC1728-2.5/LTC1728-5 Micropower Triple Supply Monitor with Open-Drain Reset
Adjustable Reset and Watchdog Time-Outs
Individual Monitor Outputs in MSOP
5-Lead SOT-23 Package
5-Lead SOT-23 Package
LTC1985-1.8
LTC2900
Micropower Triple Supply Monitor with Push-Pull Reset Output
Programmable Quad Supply Monitor
5-Lead SOT-23 Package
Adjustable Reset, 10-Lead MSOP and DFN Packages
LTC2901
Programmable Quad Supply Monitor
Adjustable Reset and Watchdog Timer,
16-Lead SSOP Package
LTC2902
Programmable Quad Supply Monitor
Adjustable Reset and Tolerance,
16-Lead SSOP Package
LTC2903
LTC2904
LTC2905
Precision Quad Supply Monitor
6-Lead SOT-23 Package
Three-State Programmable Precision Dual Supply Monitor
Three-State Programmable Precision Dual Supply Monitor
Adjustable Tolerance, 8-Lead SOT-23 and DFN Packages
Adjustable Reset and Tolerance, 8-Lead SOT-23 and
DFN Packages
LTC2906
LTC2907
LTC2909
Dual Supply Monitor with One Pin Selectable Threshold and
One Adjustable Input
0.5V Adjustable Threshold and Three Supply
Tolerances, 8-Lead SOT-23 and DFN Packages
Dual Supply Monitor with One Pin Selectable Threshold and
One Adjustable Input
0.5V Adjustable Threshold, Reset and Three Supply
Tolerances, 8-Lead SOT-23 and DFN Packages
Precision Triple/Dual Input UV, OV and Negative Voltage Monitor
Shunt Regulated V Pin, Adjustable Threshold and
CC
Reset, 8-Lead SOT-23 and DFN Packages
2908fc
LT 0708 REV C • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
© LINEAR TECHNOLOGY CORPORATION 2004
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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