FEATURES
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LTC2914
Quad UV/OV
Positive/Negative
Voltage Monitor
DESCRIPTIO
The LTC
®
2914 is a quad input voltage monitor intended for
monitoring multiple voltages in a variety of applications.
Dual inputs for each monitored voltage allow monitor-
ing four separate undervoltage (UV) conditions and four
separate overvoltage (OV) conditions. All monitors share a
common undervoltage output and a common overvoltage
output. The LTC2914-1 has latching capability for the
overvoltage output. The LTC2914-2 has functionality to
disable both the overvoltage and undervoltage outputs.
Polarity selection and a buffered reference allow monitoring
up to two separate negative voltages. A three-state input pin
allows setting the polarity of two inputs without requiring
any external components. Glitch filtering ensures reliable
reset operation without false or noisy triggering.
The LTC2914 provides a precise, versatile, space-con-
scious, micropower solution for voltage monitoring.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Monitors Four Voltages Simultaneously
Adjustable UV and OV Trip Values
Guaranteed Threshold Accuracy: ±1.5% of
Monitored Voltage over Temperature
Input Glitch Rejection
Monitors up to Two Negative Voltages
Buffered 1V Reference Output
Adjustable Reset Timeout with Timeout Disable
70µA Quiescent Current
Open-Drain OV and UV Outputs
Guaranteed OV and UV for V
CC
≥ 1V
Available in 16-Lead SSOP and 16-Lead
(5mm
×
3mm) DFN Packages
APPLICATIO S
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Desktop and Notebook Computers
Network Servers
Core, I/O Voltage Monitors
TYPICAL APPLICATIO
P0WER
SUPPLIES
5V
3.3V
2.5V
1.8V
Quad UV/OV Supply Monitor,10% Tolerance, 5V, 3.3V, 2.5V, 1.8V
0.1µF
44.2k
VH1
1k
27.4k
VL1
VH2
4.53k
1k
4.53k
19.6k
VL2
REF
VH3
1k
12.4k
VL3
VH4
4.53k
1k
VL4
GND
4.53k
TMR
C
TMR
22nF
2914 TA01a
V
CC
THRESHOLD VOLTAGE, V
OUT
(V)
0.505
SEL
OV
SYSTEM
UV
0.504
0.503
0.502
0.501
0.500
0.499
0.498
0.497
0.496
0.495
–50
–25
25
50
0
TEMPERATURE (°C)
75
100
2914 G01
LTC2914-1
LATCH
TIMEOUT = 200ms
2914f
U
U
U
Input Threshold Voltage
vs Temperature
1
LTC2914
ABSOLUTE
AXI U RATI GS
Terminal Voltages
V
CC
(Note 3)............................................. –0.3V to 6V
OV, UV ................................................... –0.3V to 16V
TMR ..........................................–0.3V to (V
CC
+ 0.3V)
VLn, VHn, LATCH, DIS, SEL .................. –0.3V to 7.5V
Terminal Currents
I
VCC
....................................................................10mA
Reference Load Current (I
REF
) ...........................±1mA
I
UV
, I
OV
...............................................................10mA
PACKAGE/ORDER I FOR ATIO
TOP VIEW
VH1
VL1
VH2
VL2
VH3
VL3
VH4
VL4
1
2
3
4
5
6
7
8
17
16 V
CC
15 TMR
14 SEL
13 LATCH
12 UV
11 OV
10 REF
9
GND
VH1
VL1
VH2
VL2
VH3
VL3
VH4
VL4
DHC PACKAGE
16-LEAD (5mm
´
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 43.5°C/W
EXPOSED PAD (PIN 17)
PCB GND CONNECTION OPTIONAL
1
2
3
4
5
6
7
8
TOP VIEW
16 V
CC
15 TMR
14 SEL
13 LATCH
12 UV
11 OV
10 REF
9
GND
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 150°C,
θ
JA
= 110°C/W
TOP VIEW
TOP VIEW
VH1
VL1
VH2
VL2
VH3
VL3
VH4
VL4
1
2
3
4
5
6
7
8
17
16 V
CC
15 TMR
14 SEL
13 DIS
12 UV
11 OV
10 REF
9
GND
VH1
VL1
VH2
VL2
VH3
VL3
VH4
VL4
DHC PACKAGE
16-LEAD (5mm
´
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 43.5°C/W
EXPOSED PAD (PIN 17)
PCB GND CONNECTION OPTIONAL
1
2
3
4
5
6
7
8
16 V
CC
15 TMR
14 SEL
13 DIS
12 UV
11 OV
10 REF
9
GND
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 150°C,
θ
JA
= 110°C/W
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
*The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.
2914f
2
U
U
W
W W
U
W
(Notes 1, 2)
Operating Temperature Range
LTC2914C ................................................ 0°C to 70°C
LTC2914I ............................................. –40°C to 85°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
SSOP ................................................................ 300°C
ORDER PART
NUMBER
LTC2914CDHC-1
LTC2914IDHC-1
DHC PART
MARKING*
29141
29141
ORDER PART
NUMBER
LTC2914CGN-1
LTC2914IGN-1
GN PART
MARKING
29141
2914I1
ORDER PART
NUMBER
LTC2914CDHC-2
LTC2914IDHC-2
DHC PART
MARKING*
29142
29142
ORDER PART
NUMBER
LTC2914CGN-2
LTC2914IGN-2
GN PART
MARKING
29142
2914I2
LTC2914
ELECTRICAL CHARACTERISTICS
SYMBOL
V
SHUNT
ΔV
SHUNT
V
CC
V
CCR(MIN)
V
CC(UVLO)
ΔV
CC(UVHYST)
I
CC
V
REF
V
UOT
t
UOD
I
VHL
t
UOTO
V
LATCH(IH)
V
LATCH(IL)
I
LATCH
V
DIS(IH)
V
DIS(IL)
I
DIS
I
TMR(UP)
I
TMR(DOWN)
V
TMR(DIS)
V
OH
V
OL
PARAMETER
V
CC
Shunt Regulator Voltage
V
CC
Shunt Regulator Load Regulation
Supply Voltage (Note 3)
Minimum V
CC
Output Valid
Supply Undervoltage Lockout
Supply Undervoltage Lockout Hysteresis
Supply Current
Reference Output Voltage
Undervoltage/Overvoltage Voltage Threshold
Undervoltage/Overvoltage Voltage Threshold
to Output Delay
VHn, VLn Input Current
UV/OV Time-Out Period
OV Latch Clear Input High
OV Latch Clear Threshold Input Low
LATCH Input Current
DIS Input High
DIS Input Low
DIS Input Current
TMR Pull-Up Current
TMR Pull-Down Current
Timer Disable Voltage
Output Voltage High UV/OV
Output Voltage Low UV/OV
V
DIS
> 0.5V
V
TMR
= 0V
V
TMR
= 1.6V
Referenced to V
CC
V
CC
= 2.3V, I
UV/OV
= –1µA
V
CC
= 2.3V, I
UV/OV
= 2.5mA
V
CC
= 1V, I
UV
= 100µA
V
LATCH
> 0.5V
C
TMR
= 1nF
VHn = V
UOT
– 5mV or VLn = V
UOT
+ 5mV
DIS = 0V
V
CC
Rising, DIS = 0V
DIS = 0V
V
CC
= 2.3V to 6V
I
VREF
= ±1mA
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 3.3V, VLn = 0.45V, VHn = 0.55V, LATCH = V
CC
, SEL = V
CC
,
DIS = Open unless otherwise noted. (Note 2)
CONDITIONS
I
CC
= 5mA
I
CC
= 2mA to 10mA
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
6.2
2.3
1.9
5
0.985
492
50
TYP
6.6
200
MAX
6.9
300
V
SHUNT
1
UNITS
V
mV
V
V
V
mV
µA
V
mV
µs
nA
ms
V
V
µA
V
V
µA
µA
µA
mV
V
2
25
70
1
500
125
2.1
50
100
1.015
508
500
±15
6
1.2
8.5
12.5
0.8
±1
1.2
0.8
1
–1.3
1.3
–180
1
0.1
0.01
0.3
0.15
0.4
1.4
0.7
0.9
1.1
±25
±30
2
–2.1
2.1
–270
3
–2.8
2.8
V
V
V
V
V
µA
µA
Three-State Input SEL
V
IL
V
IH
V
Z
I
SEL
I
SEL(MAX)
Low Level Input Voltage
High Level Input Voltage
Pin Voltage when Left in Hi-Z State
SEL High, Low Input Current
Maximum SEL Input Current
SEL Tied to Either V
CC
or GND
I
SEL
= ±10µA
●
●
●
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
reliability and lifetime.
Note 2:
All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 3:
V
CC
maximum pin voltage is limited by input current. Since the
V
CC
pin has an internal 6.5V shunt regulator, a low impedance supply that
exceeds 6V may exceed the rated terminal current. Operation from higher
voltage supplies requires a series dropping resistor. See Applications
Information.
2914f
3
LTC2914
TI I G DIAGRA S
VHn Monitor Timing
VHn
V
UOT
t
UOD
UV
1V
2914 TD01
VHn Monitor Timing (TMR Pin Strapped to V
CC
)
VHn
V
UOT
t
UOD
UV
1V
2914 TD03
NOTE:
WHEN AN INPUT IS CONFIGURED AS A NEGATIVE SUPPLY MONITOR, VHn WILL TRIGGER AN OV CONDITION AND VLn WILL TRIGGER A UV CONDITION
TYPICAL PERFOR A CE CHARACTERISTICS
Specifications are at T
A
= 25°C, V
CC
= 3.3V unless otherwise noted.
Input Threshold Voltage
vs Temperature
0.505
0.504
THRESHOLD VOLTAGE, V
OUT
(V)
0.503
0.502
I
CC
(µA)
0.501
0.500
0.499
0.498
0.497
0.496
0.495
–50
–25
25
50
0
TEMPERATURE (°C)
75
100
2914 G01
80
75
70
65
60
55
50
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2914 G02
V
CC
(V)
4
U W
W
UW
VLn Monitor Timing
VLn
V
UOT
t
UOD
OV
1V
2914 TD02
t
UOTO
t
UOTO
VLn Monitor Timing (TMR Pin Strapped to V
CC
)
VLn
V
UOT
t
UOD
OV
1V
2914 TD04
t
UOD
t
UOD
Supply Current vs Temperature
105
100
95
90
85
V
CC
= 6V
V
CC
= 3.3V
6.8
6.7
6.6
6.5
6.4
6.3
V
CC
Shunt Voltage
vs Temperature
10mA
5mA
2mA
1mA
200µA
V
CC
= 2.3V
6.2
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2914 G03
2914f
LTC2914
TYPICAL PERFOR A CE CHARACTERISTICS
Specifications are at T
A
= 25°C, V
CC
= 3.3V unless otherwise noted.
Buffered Reference Voltage
vs Temperature
1.005
TYPICAL TRANSIENT DURATION (µs)
1.004
6.65
REFERENCE VOLTAGE, V
REF
(V)
1.003
1.002
1.001
1.000
0.999
0.998
0.997
0.996
6.25
–2
0
2
6
4
I
CC
(mA)
8
10
12
0.995
–50
–25
25
50
0
TEMPERATURE (°C)
75
100
2914 G05
V
CC
Shunt Voltage vs I
CC
6.75
V
CC
(V)
6.55
25°C
–40°C
85°C
6.35
6.45
Reset Timeout Period
vs Temperature
12
UV/OV TIMEOUT PERIOD, t
UOTO
(ms)
11
0.6
UV VOLTAGE (V)
10
9
8
7
6
–50
0
C
TMR
= 1nF
0.8
UV VOLTAGE (V)
–25
0
25
50
TEMPERATURE (°C)
UV, I
SINK
vs V
CC
5
PULL-DOWN CURRENT, I
UV
(mA)
VHn = 0.45V
SEL = V
CC
1.0
4
UV AT 150mV
3
UV/OV, V
OL
(V)
0.8
UV/OV TIMEOUT PERIOD, t
UOTO
(ms)
2
UV AT 50mV
1
0
0
1
3
4
2
SUPPLY VOLTAGE, V
CC
(V)
U W
2914 G04
Transient Duration
vs Comparator Overdrive
700
600
500
400
300
200
V
CC
= 6V
100
V
CC
= 2.3V
RESET OCCURS
ABOVE CURVE
0
0.1
1
10
100
COMPARATOR OVERDRIVE PAST THRESHOLD (%)
2914 G06
UV Output Voltage vs V
CC
5
V
CC
4
UV Output Voltage vs V
CC
VHn = 0.55V
SEL = V
CC
3
0.4
UV WITH
10k PULL-UP
0.2
UV WITHOUT
10k PULL-UP
2
1
75
100
2914 G07
0
0.2
0.6
0.8
0.4
SUPPLY VOLTAGE, V
CC
(V)
1.0
2914 G08
0
0
1
3
4
2
SUPPLY VOLTAGE, V
CC
(V)
5
2914 G09
UV/OV Voltage Output Low
vs Output Sink Current
10000
Reset Timeout Period
vs Capacitance
125°C
1000
25°C
–40°C
0.6
100
0.4
10
0.2
5
2914 G10
0
0
5
10
15
20
I
UV/OV
(mA)
25
30
2914 G11
1
0.1
1
10
100
TMR PIN CAPACITANCE, C
TMR
(nF)
1000
2914 G12
2914f
5
嵌入式系统
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