LTC2913
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FEATURES
APPLICATIONS
DESCRIPTION
Dual UV/OV
Voltage Monitor
The LTC®2913 is a dual input voltage monitor intended for
multiple voltages in a variety of applications. Dual inputs for
each voltage allow monitoring two separate undervoltage
(UV) conditions and two separate overvoltage (OV)
conditions. All monitors share a common undervoltage
output and a common overvoltage output. The LTC2913-1
has latching capability for the overvoltage output. The
LTC2913- 2 has functionality to disable both the over voltage
and undervoltage outputs.
Glitch fi ltering ensures reliable reset operation without
false or noisy triggering.
The LTC2913 provides a precise, versatile, space-conscious, micropower solution for voltage monitoring.
n
Monitors Two Voltages Simultaneously
n
Adjustable UV and OV Trip Values
n
Guaranteed Threshold Accuracy: ±1.5%
n
Input Glitch Rejection
n
Adjustable Reset Timeout with Disable
n
44μA Quiescent Current
n
Open-Drain OV and UV Outputs
n
Guaranteed OV and UV for VCC ≥ 1V
n
Available in 10-Lead MSOP and (3mm × 3mm)
DFN Packages
n
Desktop and Notebook Computers
n
Network Servers
n
Core, I/O Voltage Monitors
Dual OV/UV Supply Monitor Typical Transient Duration
vs Comparator Overdrive
TYPICAL APPLICATION
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
27.4k1k
44.2k
VH1
LTC2913-1
VL1
VH2
GND TMR
SYSTEM
POWER
SUPPLIES
VL2
OV
UV
2913 TA01a
LATCH
4.53k
22nF
TIMEOUT = 200ms
1k4.53k
V
CC
0.1μF
5V
3.3V
COMPARATOR OVERDRIVE PAST THRESHOLD (%)
0.1
400
TYPICAL TRANSIENT DURATION (μs)
500
600
700
1 10 100
2913 TA01b
300
200
100
0
VCC = 2.3V
VCC = 6V
RESET OCCURS
ABOVE CURVE
LTC2913
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ABSOLUTE MAXIMUM RATINGS
Terminal Voltages
V
CC
(Note 3) ............................................. –0.3V to 6V
OV, UV ................................................... –0.3V to 16V
TMR ..........................................–0.3V to (V
CC
+ 0.3V)
VHn, VLn, LATCH, DIS .......................... –0.3V to 7.5V
Terminal Currents
I
VCC
..................................................................+10mA
I
UV
, IOV ...............................................................10mA
(Notes 1, 2)
1
2
3
4
5
VH1
VL1
VH2
VL2
GND
10
9
8
7
6
V
CC
TMR
LATCH
UV
OV
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C, θJA = 120°C/W
TOP VIEW
11
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
10
9
6
7
8
4
5
3
2
1
V
CC
TMR
LATCH
UV
OV
VH1
VL1
VH2
VL2
GND
T
JMAX
= 150°C, θJA = 43°C/W
EXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONAL
ORDER PART NUMBER MS PART MARKING* ORDER PART NUMBER DD PART MARKING*
LTC2913CMS-1
LTC2913IMS-1
LTC2913HMS-1
LTCKK
LTCKK
LTCKK
LTC2913CDD-1
LTC2913IDD-1
LTC2913HDD-1
LCKN
LCKN
LCKN
1
2
3
4
5
VH1
VL1
VH2
VL2
GND
10
9
8
7
6
V
CC
TMR
DIS
UV
OV
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C, θJA = 120°C/W
TOP VIEW
11
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
10
9
6
7
8
4
5
3
2
1
V
CC
TMR
DIS
UV
OV
VH1
VL1
VH2
VL2
GND
T
JMAX
= 150°C, θJA = 43°C/W
EXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONAL
ORDER PART NUMBER MS PART MARKING* ORDER PART NUMBER DD PART MARKING*
LTC2913CMS-2
LTC2913IMS-2
LTC2913HMS-2
LTCKM
LTCKM
LTCKM
LTC2913CDD-2
LTC2913IDD-2
LTC2913HDD-2
LCKP
LCKP
LCKP
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 identifi ed by a label on the shipping container.
Operating Temperature Range
LTC2913C ................................................ 0°C to 70°C
LTC2913I.............................................. –40°C to 85°C
LTC2913H .......................................... –40°C to 125°C
Storage Temperature Range ................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MSOP ...............................................................300°C
PACKAGE/ORDER INFORMATION
LTC2913
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ELECTRICAL CHARACTERISTICS
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.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
SHUNT
VCC Shunt Regulator Voltage ICC = 5mA
l
6.2 6.6 6.9 V
–40ºC < T
A
< 125ºC
l
6.2 6.6 7.0 V
ΔV
SHUNT
VCC Shunt Regulator Load Regulation ICC = 2mA to 10mA
l
200 300 mV
V
CC
Supply Voltage (Note 3)
l
2.3 V
SHUNT
V
V
CCR(MIN)
Minimum VCC Output Valid DIS = 0V
l
1V
V
CC(UVLO)
Supply Undervoltage Lockout DIS = 0V, VCC Rising
l
1.9 2 2.1 V
ΔV
CC(UVHYST)
Supply Undervoltage Lockout Hysteresis DIS = 0V
l
52550 mV
I
CC
Supply Current VCC = 2.3V to 6V
l
44 80 μA
V
UOT
Undervoltage/Overvoltage Threshold
l
492 500 508 mV
t
UOD
Undervoltage/Overvoltage Threshold to
Output Delay
VHn = V
UOT
– 5mV or VLn = V
UOT
+ 5mV
l
50 125 500 μs
I
VHL
VHn, VLn Input Current
l
±15 nA
–40ºC < T
A
< 125ºC
l
±30 nA
t
UOTO
UV/OV Time-Out Period C
TMR
= 1nF
l
6 8.5 12.5 mS
–40ºC < T
A
< 125ºC
l
6 8.5 14 mS
V
LATCH(VIH)
OV Latch Clear Input High
l
1.2 V
V
LATCH(VIL)
OV Latch Clear Input Low
l
0.8 V
I
LATCH
LATCH Input Current V
LATCH
> 0.5V
l
±1 μA
V
DIS(VIH)
DIS Input High
l
1.2 V
V
DIS(VIL)
DIS Input Low
l
0.8 V
I
DIS
DIS Input Current V
DIS
> 0.5V
l
123 μA
I
TMR(UP)
TMR Pull-Up Current V
TMR
= 0V
l
–1.3 –2.1 –2.8 μA
–40ºC < T
A
< 125ºC
l
–1.2 –2.1 –2.8 μA
I
TMR(DOWN)
TMR Pull-Down Current V
TMR
= 1.6V
l
1.3 2.1 2.8 μA
–40ºC < T
A
< 125ºC
l
1.2 2.1 2.8 μA
V
TMR(DIS)
Timer Disable Voltage Referenced to V
CC
l
–180 –270 mV
V
OH
Output Voltage High UV/OV VCC = 2.3V, I
UV/OV
= –1μA
l
1V
V
OL
Output Voltage Low UV/OV VCC = 2.3V, I
UV/OV
= 2.5mA
V
CC
= 1V, IUV = 100μA
l
l
0.1
0.01
0.3
0.15
V
V
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. VCC = 3.3V, VLn = 0.45V, VHn = 0.55V, LATCH = VCC,
DIS = Open unless otherwise noted. (Note 2)
Note 3: VCC 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.
LTC2913
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Specifi cations are at TA = 25°C, VCC = 3.3V unless otherwise noted.
Supply Current vs Temperature
VCC Shunt Voltage
vs Temperature
VCC Shunt Voltage vs I
CC
Typical Transient Duration
vs Comparator Overdrive
UV Output Voltage vs V
CC
TEMPERATURE (°C)
–50
0.495
TRHESHOLD VOLTAGE, V
UOT
(V)
0.497
0.499
0.501
–25
0
25 50
2913 G01
75
0.503
0.505
0.496
0.498
0.500
0.502
0.504
100
TEMPERATURE (°C)
–50
25
I
CC
(μA)
30
40
50
–25
0
25 50
2913 G02
75
55
35
45
100
VCC = 5V
VCC = 3.3V
VCC = 2.3V
TEMPERATURE (°C)
–50
6.2
V
CC
(V)
6.3
6.4
6.5
6.6
6.8
–25
02550
2913 G03
75 100
6.7
10mA
5mA
2mA
1mA
200μA
ICC (mA)
–2 0
6.25
V
CC
(V)
6.45
6.75
2
6
8
6.35
6.65
6.55
4
10
12
–40°C
25°C
85°C
COMPARATOR OVERDRIVE PAST THRESHOLD (%)
0.1
400
TYPICAL TRANSIENT DURATION (μs)
500
600
700
1 10 100
2913 G05
300
200
100
0
VCC = 2.3V
VCC = 6V
RESET OCCURS
ABOVE CURVE
SUPPLY VOLTAGE, VCC (V)
0
UV VOLTAGE (V)
0.4
0.6
0.8
2913 G06
0.2
0
0.2
0.4
0.6
1.0
0.8
V
CC
UV WITH
10k PULL-UP
UV WITHOUT
PULL-UP
TIMING DIAGRAMS
VHn Monitor Timing
V
Hn
Monitor Timing (TMR Pin Strapped to VCC)
V
Ln
Monitor Timing
V
Ln
Monitor Timing (TMR Pin Strapped to VCC)
Input Threshold Voltage
vs Temperature
V
Hn
UV
V
UOT
1V
t
UOD
t
UOTO
2913 TD01
V
Ln
OV
V
UOT
1V
t
UOD
t
UOTO
2913 TD02
V
Hn
UV
V
UOT
1V
t
UOD
t
UOD
2913 TD03
V
Ln
OV
V
UOT
1V
t
UOD
t
UOD
2913 TD04
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2913
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UV Output Voltage vs V
CC
UV, I
SINK
vs V
CC
UV/OV Voltage Output Low vs
Output Sink Current
TYPICAL PERFORMANCE CHARACTERISTICS
Reset Timeout Period vs
Temperature
Reset Timeout Period vs
Capacitance
DIS (Pin 8, LTC2913-2): Output Disable Input. Disables
the OV and UV output pins. When DIS is pulled high, the
OV and UV pins are not asserted except during a UVLO
condition. DIS has a weak (2μA) internal pull-down to
GND. Leave DIS open if unused.
Exposed Pad (Pin 11, DFN Package): Exposed Pad may
be left open or connected to device ground.
GND (Pin 5): Device Ground.
LATCH (Pin 8, LTC2913-1): OV Latch Clear/Bypass Input.
When pin is pulled low, OV is latched when asserted. When
pulled high, OV latch is cleared. While held high, OV has
the same delay and output characteristics as UV.
OV (Pin 6): Overvoltage Logic Output. Asserts low when
either VL input voltage is above threshold. Latched low
(LTC2913-1). Held low for programmed delay time after
both VL inputs are valid (LTC2913-2). OV has a weak pullup to V
CC
and may be pulled above VCC using an external
pull-up. Leave OV open if unused.
SUPPLY VOLTAGE, VCC (V)
0
UV VOLTAGE (V)
3
4
5
4
2913 G07
2
1
0
1
2
3
5
VHn = 0.55V
SEL = V
CC
SUPPLY VOLTAGE, VCC (V)
0
PULL-DOWN CURRENT, I
UV
(mA)
3
4
5
4
2913 G08
2
1
0
1
2
3
5
UV AT 150mV
UV AT 50mV
VHn = 0.45V
SEL = V
CC
I
UV/OV
(mA)
0
0
UV/OV, V
OL
(V)
0.2
0.4
0.6
0.8
1.0
85°C
–40°C
25°C
5
10 15 20
2913 G09
25 30
TEMPERATURE (°C)
–50
6
UV/OV TIMEOUT PERIOD, t
UOTO
(ms)
7
8
9
10
12
–25
02550
2913 G10
75 100
11
C
TMR
= 1nF
TMR PIN CAPACITANCE, C
TMR
(nF)
0.1 1
1
UV/OV TIMEOUT PERIOD, t
UOTO
(ms)
100
10000
10 100 1000
2913 G11
10
1000
Specifi cations are at TA = 25°C, VCC = 3.3V unless otherwise noted.
PIN FUNCTIONS
LTC2913
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PIN FUNCTIONS
TMR (Pin 9): Reset Delay Timer. Attach an external capacitor
(C
TMR
) of at least 10pF to GND to set a reset delay time
of 9ms/nF. A 1nF capacitor will generate an 8.5ms reset
delay time. Tie TMR to V
CC
to bypass timer.
UV (Pin 7): Undervoltage Logic Output. Asserts low when
either VH input voltage is below threshold. Held low for a
programmed delay time after both VH inputs are valid. UV
has a weak pull-up to V
CC
and may be pulled above VCC
using an external pull-up. Leave UV open if unused.
V
CC
(Pin 10): Supply Voltage. Bypass this pin to GND with
a 0.1μF (or greater) capacitor. Operates as a direct supply
input for voltages up to 6V. Operates as a shunt regulator for
supply voltages greater than 6V and must have a resistance
between the pin and the supply to limit input current to no
greater than 10mA. When used without a current-limiting
resistance, V
CC
voltage must not exceed 6V.
VH1/VH2 (Pin 1/Pin 3): Voltage High Inputs 1 and 2. When
the voltage on this pin is below 0.5V, an undervoltage
condition is triggered. Tie pin to V
CC
if unused.
VL1/VL2 (Pin 2/Pin 4): Voltage Low Inputs 1 and 2. When
the voltage on this pin is above 0.5V, an overvoltage condition is triggered. Tie pin to GND if unused.
0.5V
+
–
4
V
L2
3
+
–
V
H2
+
–
2
V
L1
1
+
–
V
H1
+
–
UVLO
UVLO
2V
V
CC
+
–
1V
V
CC
OV PULSE
GENERATOR
DISABLE
DISABLE
OV LATCH
CLEAR/BYPASS
LTC2913-1
TMRV
CC
9
OV
6
LATCH
8
+
–
1V
2μA
DIS
8
GND
2913 BD
5
10
UV PULSE
GENERATOR
OSCILLATOR
V
CC
400k
UV
7
400k
LTC2913-2
BLOCK DIAGRAM
LTC2913
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APPLICATIONS INFORMATION
Voltage Monitoring
The LTC2913 is a low power dual voltage monitoring
circuit with two undervoltage and two overvoltage inputs.
A timeout period that holds OV and UV asserted after all
faults have cleared is adjustable using an external capacitor
and is externally disabled.
Each voltage monitor has two inputs (VHn and VLn) for
detecting undervoltage and overvoltage conditions. When
confi gured to monitor a positive voltage V
n
using the
3-resistor circuit confi guration shown in Figure 1, VHn
is connected to the high side tap of the resistive divider
and VLn is connected to the low side tap of the resistive
divider.
3-Step Design Procedure
The following 3-step design procedure determines appropriate resistances to obtain the desired UV and OV trip
points for the voltage monitor circuit in Figure 1.
For supply monitoring, V
n
is the desired nominal operat-
ing voltage, I
n
is the desired nominal current through the
resistive divider, V
OV
is the desired overvoltage trip point
and V
UV
is the desired undervoltage trip point.
1. Choose R
A
to obtain the desired OV trip point
R
A
is chosen to set the desired trip point for the
overvoltage monitor.
RA=
0.5V
I
n
•
V
n
V
OV
(1)
2. Choose R
B
to obtain the desired UV trip point
Once R
A
is known, RB is chosen to set the desired trip
point for the undervoltage monitor.
RB=
0.5V
I
n
•
V
n
V
UV
–R
A
(2)
3. Choose R
C
to complete the design
Once, R
A
and RB are known, RC is determined by:
RC=
V
n
I
n
–RA–R
B
(3)
If any of the variables V
n
, In, VUV or VOV change, then each
step must be recalculated.
Voltage Monitor Example
A typical voltage monitor application is shown in Figure 2.
The monitored voltage is a 5V ±10% supply. Nominal current in the resistive divider is 10μA.
1. Find RA to set the OV trip point of the monitor.
RA=
0.5V
10µA
•
5V
5.5V
45.3k
2. Find RB to set the UV trip point of the monitor.
RB=
0.5V
10µA
•
5V
4.5V
– 45.3k 10.2k
3. Determine RC to complete the design.
RC=
5V
10µA
– 45.3k 10.2k 442k
Figure 1. 3-Resistor Positive UV/OV Monitoring Confi guration Figure 2. Typical Supply Monitor
–
+
–
+
+
–
0.5V
LTC2913
UV
n
VHn
R
C
R
B
R
A
2913 F01
V
n
VLn
OV
n
VH1
R
C
442k
R
B
10.2k
R
A
45.3k
V
CC
GND
LTC2913
VL1
2913 F02
OV
UV
V
CC
5V
V1
5V ±10%
LTC2913
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APPLICATIONS INFORMATION
Power-Up/Power-Down
As soon as V
CC
reaches 1V during power-up, the UV output
asserts low and the OV output weakly pulls to V
CC
.
The LTC2913 is guaranteed to assert UV low and OV high
under conditions of low V
CC
, down to VCC = 1V. Above
V
CC
= 2V (2.1V maximum), the VH and VL inputs take
control.
Once both VH inputs and V
CC
are valid, an internal timer
is started. After an adjustable delay time, UV weakly pulls
high.
Threshold Accuracy
Reset threshold accuracy is important in a supply-sensitive
system. Ideally, such a system resets only if supply voltages
fall outside the exact thresholds for a specifi ed margin.
All LTC2913 inputs have a relative threshold accuracy of
±1.5% over the full operating temperature range.
For example, when the LTC2913 is programmed to monitor a 5V input with a 10% tolerance, the desired UV trip
point is 4.5V. Because of the ±1.5% relative accuracy of
the LTC2913, the UV trip point is between 4.433V and
4.567V which is 4.5V ±1.5%.
Likewise, the accuracy of the resistances chosen for R
A
,
R
B
and RC can affect the UV and OV trip points as well.
Using the example just given, if the resistances used to
set the UV trip point have 1% accuracy, the UV trip range
is between 4.354V and 4.650V. This is illustrated in the
following calculations.
The UV trip point is given as:
VUV= 0.5V 1+
R
C
RA+ R
B
The two extreme conditions, with a relative accuracy of
1.5% and resistance accuracy of 1%, result in:
V
UV(MIN)
= 0.5V •0.985 • 1+
R
C
• 0.99
R
A
+ R
B
()
• 1.01
and
V
UV(MAX)
= 0.5V •1.015 • 1+
R
C
• 1.01
R
A
+ R
B
()
• 0.99
For a desired trip point of 4.5V,
R
C
RA+ R
B
= 8
Therefore,
V
UV(MIN)
= 0.5V •0.985 • 1+ 8
0.99
1.01
= 4.354V
and
V
UV(MAX)
= 0.5V •1.015 • 1+ 8
1.01
0.99
= 4.650V
Glitch Immunity
In any supervisory application, noise riding on the monitored DC voltage causes spurious resets. To solve this
problem without adding hysteresis, which causes a new
error term in the trip voltage, the LTC2913 lowpass fi lters
the output of the fi rst stage comparator at each input. This
fi lter integrates the output of the comparator before asserting the UV or OV logic. A transient at the input of the
comparator of suffi cient magnitude and duration triggers
the output logic. The Typical Performance Characteristics
show a graph of the Transient Duration vs. Comparator
Overdrive.
LTC2913
9
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UV/OV Timing
The LTC2913 has an adjustable timeout period (t
UOTO
) that
holds OV or UV asserted after all faults have cleared. This
assures a minimum reset pulse width allowing a settling
time delay for the monitored voltage after it has entered
the valid region of operation.
When any VH input drops below its designed threshold,
the UV pin asserts low. When all inputs recover above
their designed thresholds, the UV output timer starts. If
all inputs remain above their designed thresholds when
the timer fi nishes, the UV pin weakly pulls high. However,
if any input falls below its designed threshold during this
timeout period, the timer resets and restarts when all inputs
are above the designed thresholds. The OV output behaves
as the UV output when LATCH is high (LTC2913-1).
Selecting the UV/OV Timing Capacitor
The UV and OV timeout period (t
UOTO
) for the LTC2913
is adjustable to accommodate a variety of applications.
Connecting a capacitor, C
TMR
, between the TMR pin and
ground sets the timeout period. The value of capacitor
needed for a particular timeout period is:
C
TMR
= t
UOTO
• 115 • 10–9 [F/s]
The Reset Timeout Period vs Capacitance graph found in
the Typical Performance Characteristics shows the desired
delay time as a function of the value of the timer capacitor
that must be used. The TMR pin must have a minimum
10pF load or be tied to V
CC
. For long timeout periods, the
only limitation is the availability of a large value capacitor
with low leakage. Capacitor leakage current must not exceed
the minimum TMR charging current of 1.3μA. Tying the
TMR pin to V
CC
will bypass the timeout period.
Undervoltage Lockout
When V
CC
falls below 2V, the LTC2913 asserts an
undervoltage lockout (UVLO) condition. During UVLO,
UV is asserted and pulled low while OV is cleared and
blocked from asserting. When V
CC
rises above 2V, UV
follows the same timing procedure as an undervoltage
condition on any input.
Shunt Regulator
The LTC2913 has an internal shunt regulator. The V
CC
pin
operates as a direct supply input for voltages up to 6V.
Under this condition, the quiescent current of the device
remains below a maximum of 80μA. For V
CC
voltages higher
than 6V, the device operates as a shunt regulator and must
have a resistance R
Z
between the supply and the VCC pin
to limit the current to no greater than 10mA.
When choosing this resistance value, select an appropriate
location on the I-V curve shown in the Typical Performance
Characteristics to accommodate any variations in V
CC
due
to changes in current through R
Z
.
UV and OV Output Characteristics
The DC characteristics of the UV and 0V pull-down strength
are shown in the Typical Performance Characteristics. Each
pin has a weak internal pull-up to V
CC
and a strong pulldown to ground. This arrangement allows these pins to
have open-drain behavior while possessing several other
benefi cial characteristics. The weak pull-up eliminates the
need for an external pull-up resistor when the rise time on
the pin is not critical. On the other hand, the open-drain
confi guration allows for wired-OR connections, and is
useful when more than one signal needs to pull down
on the output. V
CC
of 1V guarantees a maximum VOL =
0.15V at UV.
At V
CC
= 1V, the weak pull-up current on OV is barely turned
on. Therefore, an external pull-up resistor of no more than
100k is recommended on the OV pin if the state and pull-up
strength of the OV pin is crucial at very low V
CC
.
Note however, by adding an external pull-up resistor, the
pull-up strength on the OV pin is increased. Therefore, if
it is connected in a wired-OR connection, the pull-down
strength of any single device must accommodate this
additional pull-up strength.
Output Rise and Fall Time Estimation
The UV and OV outputs have strong pull-down capability. The following formula estimates the output fall time
(90% to 10%) for a particular external load capacitance
(C
LOAD
):
t
FALL
≈ 2.2 • RPD • C
LOAD
APPLICATIONS INFORMATION
LTC2913
10
2913fb
APPLICATIONS INFORMATION
where RPD is the on-resistance of the internal pull-down
transistor, typically 50Ω at V
CC
> 1V and at room tem-
perature (25°C). C
LOAD
is the external load capacitance
on the pin. Assuming a 150pF load capacitance, the fall
time is 16.5ns.
The rise time on the UV and OV pins is limited by a 400k
pull-up resistance to V
CC
. A similar formula estimates the
output rise time (10% to 90%) at the UV and OV pins:
t
RISE
≈ 2.2 • RPU • C
LOAD
where RPU is the pull-up resistance.
OV Latch (LTC2913-1)
With the LATCH pin held low, the OV pin latches low when
an OV condition is detected. The latch is cleared by raising
the LATCH pin high. If an OV condition clears while LATCH
is held high, the latch is bypassed and the OV pin behaves
the same as the UV pin with a similar timeout period at the
output. If LATCH is pulled low while the timeout period is
active, the OV pin latches as before.
Disable (LTC2913-2)
The LTC2913-2 allows disabling the UV and OV outputs
via the DIS pin. Pulling DIS high will force both outputs
to remain weakly pulled high, regardless of any faults
that occur on the inputs. However, if a UVLO condition
occurs, UV asserts and pulls low, but the timeout function
is bypassed. UV pulls high as soon as the UVLO condition
is cleared.
DIS has a weak 2μA (typical) internal pull-down current
guaranteeing normal operation with the pin left open.
Dual UV/OV Supply Monitor, 10% Tolerance, 5V, 3.3V
Supply Monitor Powered from 12V, 10% Tolerance, 12V, 5V
R
C2
27.4k
R
B1
1k
R
C1
44.2k
10
6
7
8
95
4
3
2
1
VH1
VL1
VH2
GND TMR
SYSTEM
POWER
SUPPLIES
VL2
OV
UV
2913 TA02
LATCH
R
A2
4.53k
C
TMR
22nF
TIMEOUT = 200ms
R
B2
1k
R
A1
4.53k
V
CC
LTC2913-1
C
BYP
0.1μF
5V
3.3V
R
C2
44.2k
R
B1
1k
R
C1
115k
R
Z
10k
10
6
7
8
9
5
4
3
2
1
VH1
VL1
VH2
GND
TMR
SYSTEM
POWER
SUPPLIES
VL2
OV
UV
2913 TA03
DIS
R
A2
4.53k
R
B2
1k
R
A1
4.53k
V
CC
LTC2913-2
C
BYP
0.1μF
12V
5V
TYPICAL APPLICATIONS
LTC2913
11
2913fb
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
DD Package
10-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1699)
MS Package
10-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1661)
3.00 ±0.10
(4 SIDES)
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).
CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT
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
0.38 ± 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 ± 0.10
(2 SIDES)
0.75 ±0.05
R = 0.115
TYP
2.38 ±0.10
(2 SIDES)
15
106
PIN 1
TOP MARK
(SEE NOTE 6)
0.200 REF
0.00 – 0.05
(DD10) DFN 1103
0.25 ± 0.05
2.38 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 ±0.05
(2 SIDES)2.15 ±0.05
0.50
BSC
0.675 ±0.05
3.50 ±0.05
PACKAGE
OUTLINE
0.25 ± 0.05
0.50 BSC
MSOP (MS) 0603
0.53 ± 0.152
(.021 ± .006)
SEATING
PLANE
0.18
(.007)
1.10
(.043)
MAX
0.17 – 0.27
(.007 – .011)
TYP
0.127 ± 0.076
(.005 ± .003)
0.86
(.034)
REF
0.50
(.0197)
BSC
12
3
45
4.90 ± 0.152
(.193 ± .006)
0.497 ± 0.076
(.0196 ± .003)
REF
8910
7
6
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
0.254
(.010)
0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.889 ± 0.127
(.035 ± .005)
RECOMMENDED SOLDER PAD LAYOUT
0.305 ± 0.038
(.0120 ± .0015)
TYP
0.50
(.0197)
BSC
LTC2913
12
2913fb
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2006
LT 1007 • REV B • PRINTED IN USA
TYPICAL APPLICATION
Dual UV/OV Supply Monitor with LED Undervoltage and Overvoltage Indicator and Manual
Undervoltage Reset Button, 10% Tolerance, 12V, 5V
PART NUMBER DESCRIPTION COMMENTS
LTC1326/
LTC1326-2.5
Micropower Precision Triple Supply Monitor for 5V/2.5V, 3.3V
and ADJ
4.725V, 3.118V, 1V Threshold (±0.75%)
LTC1726-2.5/
LTC1726-5
Micropower Triple Supply Monitor for 2.5V/5V, 3.3V and ADJ Adjustable RESET and Watchdog Time-Outs
LTC1727-2.5/
LTC1727-5
Micropower Triple Supply Monitor with Open-Drain Reset Individual Monitor Outputs in MSOP
LTC1728-1.8/
LTC1728-3.3
Micropower Triple Supply Monitor with Open-Drain Reset 5-Lead SOT-23 Package
LTC1728-2.5/
LTC1728-5
Micropower Triple Supply Monitor with Open-Drain Reset 5-Lead SOT-23 Package
LTC1985-1.8 Micropower Triple Supply Monitor with Open-Drain Reset 5-Lead SOT-23 Package
LTC2900 Programmable Quad Supply Monitor Adjustable RESET, 10-Lead MSOP and 3mm × 3mm
10-Lead DFN Package
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,
Margining Functions
LTC2903 Precision Quad Supply Monitor 6-Lead SOT-23 Package, Ultralow Voltage Reset
LTC2904 3-State Programmable Precision Dual Supply Monitor Adjustable Tolerance, 8-Lead SOT-23 Package
LTC2905 3-State Programmable Precision Dual Supply Monitor Adjustable RESET and Tolerance, 8-Lead SOT-23 Package
LTC2906 Precision Dual Supply Monitor 1-Selectable and 1 Adjustable Separate V
CC
Pin, RST/RST Outputs
LTC2907 Precision Dual Supply Monitor 1-Selectable and 1 Adjustable Separate V
CC
, Adjustable Reset Timer
LTC2908 Precision Six Supply Monitor (Four Fixed & 2 Adjustable) 8-Lead SOT-23 and DFN Packages
LTC2909 Prevision Dual Input UV, OV and Negative Voltage Monitor Separate V
CC
Pin, Adjustable Reset Timer, 8-Lead TSOT-23 and
DFN Packages
LTC2910 Octal Positive/Negative Voltage Monitor Separate V
CC
Pin, Eight Inputs, Up to Two Negative Monitors
Adjustable Reset Timer, 16-Lead SSOP and DFN Packages
LTC2914 Quad UV/OV Positive/Negative Voltage Monitor Separate V
CC
Pin, Four inputs, Up To Two Negative Monitors,
Adjustable Reset Timer, 16-Lead SSOP and DFN Packages
2.05M
10k100k
510Ω
LED
1k
44.2k
VH1
VL1
VH2
GND TMR
SYSTEM
POWER
SUPPLIES
VL2
OV
UV
2913 TA05
DIS
22nF
TIMEOUT = 200ms
4.53k
MANUAL
RESET BUTTON
(NORMALLY OPEN)
V
CC
LTC2913-2
0.1μF
12V
5V
510Ω
LED
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