LM3724I4.63MWC [TI]
IC 1-CHANNEL POWER SUPPLY SUPPORT CKT, UUC, WAFER, Power Management Circuit;
| 型号： | LM3724I4.63MWC |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | IC 1-CHANNEL POWER SUPPLY SUPPORT CKT, UUC, WAFER, Power Management Circuit |
| 文件： | 总25页 (文件大小：422K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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June 2001
LM3722/LM3723/LM3724
5-Pin Microprocessor Reset Circuits
General Description
Features
n Precise monitoring of 2.5V, 3.3V, and 5V supply
voltages
The LM3722/LM3723/LM3724 microprocessor supervisory
circuits monitor the power supplies in microprocessor and
digital systems. They provide a reset to the microprocessor
during power-up, power-down, brown-out conditions, and
manual reset.
n Fully specified over temperature
Industrial: −40˚C to +85˚C
Extended: −40˚C to +125˚C
n 100 ms minimum Power-On Reset pulse width, 190 ms
typical:
The LM3722/LM3723/LM3724 asserts a reset signal when-
ever the supply decreases below the factory-programmed
reset threshold for at least 100 ms. The reset signal remains
asserted for 190 ms after VCC rises above the threshold.
Active-Low RESET Output (LM3722)
Active-High RESET Output (LM3723)
Active-Low RESET Open Drain Output (LM3724)
n Guaranteed RESET Output valid for VCC ≥ 1V
n Low Supply Current, 6µA typical
n Power supply transient immunity
n Compatible with MAX811/812 applications
The LM3722 has an active-low RESET push-pull output. The
LM3723 has an active-high RESET push-pull output. The
LM3724 has an active-low open-drain RESET output.
Three standard reset voltage options are available, suitable
for monitoring 5V, 3.3V, and 2.5V supply voltages. Additional
reset voltages are also available; contact National Semicon-
ductor for details.
Applications
n Microprocessor Systems
n Computers
n Controllers
n Intelligent Instruments
n Portable/Battery-Powered Equipment
With
a
low supply current of only 6µA, the
LM3722/LM3723/LM3724 are ideal for use in portable equip-
ment. The LM3722/LM3723/LM3724 are available in the
5-pin SOT23 package.
Typical Application Circuit
20014401
20014437
Connection Diagram
SOT23-5
20014402
*
( ) are for LM3723
© 2001 National Semiconductor Corporation
DS200144
www.national.com
Ordering Information
Industrial Temperature Range (−40˚C to +85˚C):
Reset
Threshold (V)
4.63
LM3722 Supplied as
1000 units, tape & reel
LM3722IM5-4.63
LM3722 Supplied as
3000 units, tape & reel
LM3722IM5X-4.63
Package
Top Mark
R43B
Package
Type
NSC Package
3.08
LM3722IM5-3.08
LM3722IM5X-3.08
R41B
SOT23-5
MF05A
2.32
LM3722IM5-2.32
LM3722IM5X-2.32
R34B
Reset
Threshold (V)
4.63
LM3723 Supplied as
1000 units, tape & reel
LM3723IM5-4.63
LM3723 Supplied as
3000 units, tape & reel
LM3723IM5X-4.63
Package
Top Mark
R13B
Package
Type
NSC Package
3.08
LM3723IM5-3.08
LM3723IM5X-3.08
R11B
SOT23-5
MF05A
2.32
LM3723IM5-2.32
LM3723IM5X-2.32
R46B
Reset
Threshold (V)
4.63
LM3724 Supplied as
1000 units, tape & reel
LM3724IM5-4.63
LM3724 Supplied as
3000 units, tape & reel
LM3724IM5X-4.63
Package
Top Mark
R55B
Package
Type
NSC Package
3.08
LM3724IM5-3.08
LM3724IM5X-3.08
R53B
SOT23-5
MF05A
2.32
LM3724IM5-2.32
LM3724IM5X-2.32
R50B
Extended Temperature Range (−40˚C to +125˚C):
Reset
Threshold (V)
4.63
LM3722 Supplied as
1000 units, tape & reel
LM3722EM5-4.63
LM3722 Supplied as
3000 units, tape & reel
LM3722EM5X-4.63
LM3722EM5X-3.08
LM3722EM5X-2.32
Package
Top Mark
R56B
Package
Type
NSC Package
3.08
LM3722EM5-3.08
R57B
SOT23-5
MF05A
2.32
LM3722EM5-2.32
R58B
Reset
Threshold (V)
4.63
LM3723 Supplied as
1000 units, tape & reel
LM3723EM5-4.63
LM3723 Supplied as
3000 units, tape & reel
LM3723EM5X-4.63
LM3723EM5X-3.08
LM3723EM5X-2.32
Package
Top Mark
R59B
Package
Type
NSC Package
3.08
LM3723EM5-3.08
R60
SOT23-5
MF05A
2.32
LM3723EM5-2.32
R61B
Reset
Threshold (V)
4.63
LM3724 Supplied as
1000 units, tape & reel
LM3724EM5-4.63
LM3724 Supplied as
3000 units, tape & reel
LM3724EM5X-4.63
LM3724EM5X-3.08
LM3724EM5X-2.32
Package
Top Mark
R62B
Package
Type
NSC Package
3.08
LM3724EM5-3.08
R63B
SOT23-5
MF05A
2.32
LM3724EM5-2.32
R64B
Custom voltages and improved accuracies are available, subject to minimum orders. Contact your local National Semiconductor Sales Office for information.
www.national.com
2
Pin Description
PIN
1
NAME
FUNCTION
GND
GND
Ground reference
2
Ground reference, device substrate, connect to ground.
RESET
Active-low output. RESET remains low while VCC is below the reset threshold
voltage, and for 190 ms after VCC rises above the reset threshold voltage.
Active-high output. RESET remains high while VCC is below the reset threshold, and
for 190 ms after VCC rises above the reset threshold.
LM3722/LM3724
RESET
3
LM3723
Active-low input. Reset is asserted whenever this pin is pulled low and remains
asserted for 190 ms after the MR pin goes high. May be left open.
Supply Voltage (+5V, +3.3V, or +2.5V, nominal)
4
5
MR
VCC
Block Diagram
LM3722/LM3723/LM3724 Block Diagram
20014435
3
www.national.com
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Continuous Power Dissipation (TA = +70˚C)
SOT-23 (Note 3)
320mW
Operating Temperature Range
Industrial:
−40˚C to +85˚C
−40˚C to +125˚C
125˚C
V
CC, MR
−0.3V to 6.0V
−0.3V to (VCC+ 0.3V)
20mA
Extended:
RESET, RESET
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature
(soldering, 10sec)
Input Current, VCC Pin
Output Current, RESET,
RESET Pin
−65˚C to +160˚C
20mA
2kV
+300˚C
ESD Rating (Note 2)
Electrical Characteristics
Typical values are at TA = +25˚C. Limits with standard typeface are for TA = +25˚C, and limits in boldface type apply for the
operating temperature range (−40˚C to +85˚C) for LM372_IM5X, and (−40˚C to +125˚C) for LM372_EM5X, unless otherwise
noted. (Note 4)
Symbol
Parameter
VCC Range
Conditions
Min
1.0
Typ
Max
5.5
Units
V
VCC
LM372 _ -4.63
LM372 _ -3.08
LM372 _ -2.32
VCC = 5.5V
VCC = 3.6V
VCC = 2.5V
8
7
15
µA
Supply Current
(ILOAD = 0A)
ICC
10
6
10
4.54
4.50
3.03
3.00
2.27
2.25
4.63
4.72
4.75
3.14
3.15
2.37
2.40
LM372 _ -4.63
LM372 _ -3.08
LM372 _ -2.32
3.08
2.32
VTH
Reset Threshold
Reset Threshold
V
VTH
30
ppm/˚C
Tempco Temperature Coefficient
tRD
tRP
tMR
VCC to Reset Delay (Note 5) VCC = VTH to (VTH − 100mV)
Reset Active Timeout Period
MR Minimum Pulse Width
20
µs
ms
µs
100
10
190
560
MR to Reset Propagation
tMD
2
µs
ns
Delay
MR Glitch Immunity (Note 6)
100
VIH
VIL
VIH
VIL
2.3
>
VCC VTH(MAX), LM372_ -4.63
0.8
0.25 VCC
0.3
MR Input Threshold
V
>
0.7 VCC
VCC VTH(MAX), LM372_ -3.08, LM372_
-2.32
MR Pull-Up Resistance
22
kΩ
VCC = VTH min, ISINK = 1.2mA,
(LM3722-2.32/3.08)
RESET Output Voltage Low
(LM3722)
VOL
VCC = VTH min, ISINK = 3.2mA,
(LM3722-4.63)
0.4
V
>
VCC 1V, ISINK = 50µA
0.3
>
VCC VTH max, ISOURCE = 500µA,
0.8VCC
(LM3722-2.32/3.08)
RESET Output Voltage High
(LM3722)
VOH
V
V
>
VCC VTH max, ISOURCE = 800µA,
VCC−1.5
(LM3722-4.63)
VCC = VTH max, ISINK = 1.2mA
(LM3723 -2.32/3.08)
0.3
0.4
RESET Output Voltage Low
(LM3723)
VOL
VCC = VTH max, ISINK = 3.2mA
(LM3723 -4.63)
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4
Electrical Characteristics (Continued)
Typical values are at TA = +25˚C. Limits with standard typeface are for TA = +25˚C, and limits in boldface type apply for the
operating temperature range (−40˚C to +85˚C) for LM372_IM5X, and (−40˚C to +125˚C) for LM372_EM5X, unless otherwise
noted. (Note 4)
Symbol
Parameter
RESET Output Voltage High
(LM3723)
Conditions
1.8V VCC VTH min, ISOURCE = 150µA
Min
Typ
Max
Units
VOH
0.8VCC
V
<
<
VOL
RESET Output Voltage Low VCC = VTH min, ISINK = 1.2 mA
0.3
0.4
V
(LM3724)
(LM3724 -2.32/3.08)
VCC = VTH min, ISINK = 3.2 mA
(LM3724 -4.63)
>
VCC 1V, ISINK = 50µA
0.3
0.5
IIN
RESET Output Leakage
Current (LM3724)
µA
>
VCC VTH, RESET = 5.5V
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which the device operates
correctly. Operating ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical
Characteristics.
Note 2: The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
Note 3: At elevated temperatures, devices must be derated based on package thermal resistance. The device in the SOT23-5 package must be derated at
4.5mW/˚C at ambient temperatures above 70˚C. The device has internal thermal protection.
Note 4: Production testing done at T = +25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control
A
(SQC) methods.
Note 5: RESET Output for LM3722 and LM3724, RESET output for LM3723.
Note 6: Glitches of 100 ns or less typically will not generate a reset pulse.
5
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Typical Performance Characteristics
Supply Current vs VCC
Supply Current vs Temperature
Reset Timeout vs Temperature
LM3724 VOL vs Current
20014403
20014407
Reset Timeout vs VCC
20014408
20014404
Normalized VTH vs Temperature
20014416
20014405
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6
Typical Performance Characteristics (Continued)
LM3724 Low VCC Characteristics
20014406
7
www.national.com
Timing Diagram
20014412
Reset Threshold
Circuit Information
The LM3722/LM3723/LM3724 are available with reset volt-
ages of 4.63V, 3.08V, and 2.32V which are suitable for
monitoring 5.0V, 3.3V, and 2.5V supplies respectively. Other
reset thresholds in the 2.20V to 5.0V range, in 10 mV steps,
are available; contact National Semiconductor for details.
Reset Output
The reset input of a µP initializes the device into a known
state. The LM3722/LM3723/LM3724 microprocessor voltage
monitoring circuits assert a forced reset output to prevent
code execution errors during power-up, power-down, and
brownout conditions.
Manual Reset Input (MR)
Many µP-based products require a manual reset capability,
allowing the operator to initiate a reset. The MR input is fully
debounced and provides an internal 22 kΩ pull-up. When the
MR input is pulled below VIL (0.25VCC) for more than 100 ns,
reset is asserted after a typical delay of 2 µs. Reset remains
active as long as MR is held low, and releases after MR rises
above VIH and the reset timeout period expires. Use MR with
digital logic to assert reset or to daisy chain supervisory
circuits.
RESET is guaranteed valid for VCC ≥ 1V. Once VCC exceeds
the reset threshold, an internal timer maintains the output for
the reset timeout period. After this interval, reset goes high
and the microprocessor initializes itself into a known state.
The LM3722 and LM3724 offer an active-low RESET; the
LM3723 offers an active-high RESET.
As VCC drops below the reset threshold (such as during a
brownout), the reset activates (see the Negative-Going VCC
Transients section). When VCC again rises above the reset
threshold, the internal timer starts. Reset holds until VCC
exceeds the reset threshold for longer than the reset timeout
period. After this time, reset releases.
Applications Information
Benefits of Precision Reset Thresholds
Additionally, the Manual Reset input (MR) will initiate a
forced reset. See the Manual Reset Input section.
A microprocessor supply supervisor must provide a reset
output within a predictable range of the supply voltage. A
common threshold range is between 5% and 10% below the
nominal supply voltage. The 4.63V, 3.08V and 2.32V options
of the LM3722/LM3723/LM3724 use highly accurate circuitry
to ensure that the reset threshold occurs only within this
range (for 5.0V, 3.3V and 2.5V supplies). Table 1 shows how
the standard reset thresholds apply to 5.0V, 3.3V, and 2.5V
nominal supply voltages.
The LM3722/LM3723/LM3724 reset outputs ignore short du-
ration glitches on VCC and MR. See the Applications Infor-
mation section for details.
www.national.com
8
resistor must be small enough so that the leakage current of
all connected devices does not create an excessive voltage
drop when the output is not activated. A resistor value of 100
kΩ will generally suffice.
Applications Information (Continued)
TABLE 1. Monitored Tolerance Table
Supply Voltage
3.3V
Reset
Threshold
2.5V
5.0V
90.8-94.4%
Negative-Going VCC Transients
±
±
±
The LM3722/LM3723/LM3724 are relatively immune to short
negative-going transients or glitches on VCC. Figure 2 shows
the maximum pulse width a negative-going VCC transient
can have without causing a reset pulse. In general, as the
magnitude of the transient increases, going further below the
threshold, the maximum allowable pulse width decreases.
Typically, a VCC transient that goes 125 mV below the reset
threshold and lasts 40 µs or less will not cause a reset pulse.
A 0.1 µF bypass capacitor mounted as close as possible to
the VCC pin will provide additional transient rejection.
4.63
3.08
2.32
%
%
%
91.8-95.2%
90.8-94.8%
Ensuring a Valid Reset Output Down to VCC = 0V
When VCC falls below 1V, the LM3722 RESET output is
unable to sink the rated current. A high-impedance CMOS
logic input connected to RESET can therefore drift to unde-
termined voltages. To prevent this situation, a 100kΩ resistor
should be connected from the RESET output to ground, as
shown in Figure 1.
A 100kΩ pull-up resistor to VCC is also recommended for the
<
LM3723, if RESET is required to remain valid for VCC 1V.
20014410
20014414
FIGURE 1. Circuit for RESET Valid from VCC = 0V
Open Drain Output (LM3724)
FIGURE 2. Maximum Transient Duration without
Causing a Reset Pulse vs. Reset Comparator
Overdrive
An open drain output allows easy paralleling of multiple
microprocessor reset circuits without requiring additional
logic gates. Open drain outputs also allow interfacing de-
vices of differing logic levels or families, since the output
pull-up resistor may be connected to any supply voltage up
Interfacing to µPs with Bidirectional Reset Pins
Microprocessors with bidirectional reset pins, such as the
Motorola 68HC11 series, can be connected to the LM3722
RESET output. To ensure a correct output on the LM3722
even when the microprocessor reset pin is in the opposite
state, connect a 4.7kΩ resistor between the LM3722 RESET
output and the µP reset pin, as shown in Figure 3. Buffer the
LM3722 RESET output to other system components.
to 5.5V, regardless of LM3724 VCC
.
The pull up resistor is calculated so that maximum current
flow into RESET is less than 10 mA when activated. The
9
www.national.com
Typical Application Circuits
20014411
FIGURE 3. Interfacing to Microprocessors with Bidirectional Reset I/O
20014422
FIGURE 4. Regulator/Switch with Long-Term Overvoltage Lockout Prevents Overdissipation in Linear Regulator
www.national.com
10
Typical Application Circuits (Continued)
20014431
FIGURE 5. LM3722 Switch Debouncer
20014424
FIGURE 6. LM3723 Power-On Delay
11
www.national.com
Physical Dimensions inches (millimeters)
unless otherwise noted
5-Lead SOT23-5
For Ordering, refer to Ordering Information table
NS Package Number MF05A
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
National Semiconductor
Corporation
Americas
National Semiconductor
Europe
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
Fax: +49 (0) 180-530 85 86
Email: support@nsc.com
Email: europe.support@nsc.com
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English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
Email: ap.support@nsc.com
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National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
See A/D Converters
Products
Products > Analog - Regulators > Regulator Control & Supervisory Function > LM3723
LM3723 Product Folder
5-Pin Microprocessor Reset Circuits
Generic P/N 3723
General
Description
Package
& Models
Samples
& Pricing
Features
Datasheet
Parametric Table
Parametric Table
Multiple Output Capability
On/Off Pin
No
Yes
Yes
1
Output Current, max
Output Voltage (Volt)
Adjustable Output
20 mA
-
Error Flag
Yes
-
Input Voltage, min (Volt)
Input Voltage, max (Volt)
Switching Frquency (Hz)
Adjustable Switching
Sync Pin
6
No
No
Datasheet
Title
Size in Kbytes Date
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View Online
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5-Jun-01
LM3722 LM3723 LM3724 5-Pin
Microprocessor Reset Circuits
219 Kbytes
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Package Availability, Models, Samples & Pricing
Budgetary
Pricing
Samples &
Electronic
Orders
Std
Pack
Size
Package
Models
Package
Marking
Part Number
Status
Type Pins MSL
SPICE IBIS
Qty $US each
Samples
reel
of
1000
R61B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3723EM5-2.32
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
Buy Now
Samples
reel
of
1000
R60B
¢Z¢1¢T
LM3723EM5-3.08
LM3723EM5-4.63
Buy Now
Samples
reel
of
1000
R59B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R46B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3723IM5-2.32
LM3723IM5-3.08
LM3723IM5-4.63
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.8000
$0.8000
$0.8000
Buy Now
Samples
reel
of
1000
R11B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R13B
¢Z¢1¢T
Buy Now
reel
of
3000
R61B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
MSL
MSL
MSL
LM3723EM5X-2.32
LM3723EM5X-3.08
LM3723EM5X-4.63
LM3723IM5X-2.32
LM3723IM5X-3.08
LM3723IM5X-4.63
LM3723E2.32 MDC
LM3723E3.08 MDC
LM3723E4.63 MDC
LM3723I2.32 MDC
LM3723I3.08 MDC
LM3723I4.63 MDC
LM3723E2.32 MWC
LM3723E3.08 MWC
5
5
5
5
5
5
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1K+
1K+
1K+
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
$0.8000
$0.8000
$0.8000
reel
of
3000
R60B
¢Z¢1¢T
reel
of
3000
R59B
¢Z¢1¢T
reel
of
3000
R46B
¢Z¢1¢T
reel
of
3000
R11B
¢Z¢1¢T
reel
of
3000
R13B
¢Z¢1¢T
tray
of
N/A
Samples
Samples
Samples
Samples
Samples
Samples
Die
-
-
-
-
-
-
-
-
tray
of
N/A
Die
Die
Die
Die
Die
tray
of
N/A
tray
of
N/A
tray
of
N/A
tray
of
N/A
wafer jar
of
Wafer
Wafer
N/A
wafer jar
of
N/A
wafer jar
of
Wafer
Wafer
Wafer
Wafer
LM3723E4.63 MWC
LM3723I2.32 MWC
LM3723I3.08 MWC
LM3723I4.63 MWC
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
-
-
-
-
N/A
wafer jar
of
N/A
wafer jar
of
N/A
wafer jar
of
N/A
General Description
The LM3722/LM3723/LM3724 microprocessor supervisory circuits monitor the power supplies in
microprocessor and digital systems. They provide a reset to the microprocessor during power-up, power-
down, brown-out conditions, and manual reset.
The LM3722/LM3723/LM3724 asserts a reset signal whenever the supply decreases below the factory-
programmed reset threshold for at least 100 ms. The reset signal remains asserted for 190 ms after VCC
rises above the threshold.
The LM3722 has an active-low RESET# push-pull output. The LM3723 has an active-high RESET push-pull
output. The LM3724 has an active-low open-drain RESET# output.
Three standard reset voltage options are available, suitable for monitoring 5V, 3.3V, and 2.5V supply
voltages. Additional reset voltages are also available; contact National Semiconductor for details.
With a low supply current of only 6µA, the LM3722/LM3723/LM3724 are ideal for use in portable equipment.
The LM3722/LM3723/LM3724 are available in the 5-pin SOT23 package.
Features
●
●
●
Precise monitoring of 2.5V, 3.3V, and 5V supply voltages
Fully specified over temperature Industrial: -40°C to +85°C Extended: -40°C to +125°C
100 ms minimum Power-On Reset pulse width, 190 ms typical: Active-Low RESET# Output (LM3722)
Active-High RESET Output (LM3723) Active-Low RESET# Open Drain Output (LM3724)
Guaranteed RESET# Output valid for VCC >= 1V
●
●
●
●
Low Supply Current, 6µA typical
Power supply transient immunity
Compatible with MAX811/812 applications
Applications
●
●
●
●
●
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Portable/Battery-Powered Equipment
[Information as of 5-Aug-2002]
Search
Design
Purchasing
Quality
Company
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See Wireless Products
Products > Analog - Regulators > Regulator Control & Supervisory Function > LM3722
LM3722 Product Folder
5-Pin Microprocessor Reset Circuits
Generic P/N 3722
General
Description
Package
& Models
Samples
& Pricing
Features
Datasheet
Parametric Table
Parametric Table
Multiple Output Capability
On/Off Pin
No
Yes
Yes
1
Output Current, max
Output Voltage (Volt)
Adjustable Output
20 mA
-
Error Flag
Yes
-
Input Voltage, min (Volt)
Input Voltage, max (Volt)
Switching Frquency (Hz)
Adjustable Switching
Sync Pin
6
No
No
Datasheet
Title
Size in Kbytes Date
Receive via Email
Download
View Online
View Online Download Receive via Email
5-Jun-01
LM3722 LM3723 LM3724 5-Pin
Microprocessor Reset Circuits
219 Kbytes
If you have trouble printing or viewing PDF file(s), see Printing Problems.
Package Availability, Models, Samples & Pricing
Budgetary
Pricing
Samples &
Electronic
Orders
Std
Pack
Size
Package
Models
Package
Marking
Part Number
Status
Type Pins MSL
SPICE IBIS
Qty $US each
Samples
reel
of
1000
R58B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3722EM5-2.32
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
Buy Now
Samples
reel
of
1000
R57B
¢Z¢1¢T
LM3722EM5-3.08
LM3722EM5-4.63
Buy Now
Samples
reel
of
1000
R56B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R34B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3722IM5-2.32
LM3722IM5-3.08
LM3722IM5-4.63
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.8000
$0.8000
$0.8000
Buy Now
Samples
reel
of
1000
R41B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R43B
¢Z¢1¢T
Buy Now
reel
of
3000
R58B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
MSL
MSL
MSL
LM3722EM5X-2.32
LM3722EM5X-3.08
LM3722EM5X-4.63
LM3722IM5X-2.32
LM3722IM5X-3.08
LM3722IM5X-4.63
LM3722E2.32 MDC
LM3722E3.08 MDC
LM3722E4.63 MDC
LM3722I2.32 MDC
LM3722I3.08 MDC
LM3722I4.63 MDC
LM3722E2.32 MWC
LM3722E3.08 MWC
5
5
5
5
5
5
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1K+
1K+
1K+
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
$0.8000
$0.8000
$0.8000
reel
of
3000
R57B
¢Z¢1¢T
reel
of
3000
R56B
¢Z¢1¢T
reel
of
3000
R34B
¢Z¢1¢T
reel
of
3000
R41B
¢Z¢1¢T
reel
of
3000
R43B
¢Z¢1¢T
tray
of
N/A
Samples
Samples
Samples
Samples
Samples
Samples
Die
-
-
-
-
-
-
-
-
tray
of
N/A
Die
Die
Die
Die
Die
tray
of
N/A
tray
of
N/A
tray
of
N/A
tray
of
N/A
wafer jar
of
Wafer
Wafer
N/A
wafer jar
of
N/A
wafer jar
of
Wafer
Wafer
Wafer
Wafer
LM3722E4.63 MWC
LM3722I2.32 MWC
LM3722I3.08 MWC
LM3722I4.63 MWC
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
-
-
-
-
N/A
wafer jar
of
N/A
wafer jar
of
N/A
wafer jar
of
N/A
General Description
The LM3722/LM3723/LM3724 microprocessor supervisory circuits monitor the power supplies in
microprocessor and digital systems. They provide a reset to the microprocessor during power-up, power-
down, brown-out conditions, and manual reset.
The LM3722/LM3723/LM3724 asserts a reset signal whenever the supply decreases below the factory-
programmed reset threshold for at least 100 ms. The reset signal remains asserted for 190 ms after VCC
rises above the threshold.
The LM3722 has an active-low RESET# push-pull output. The LM3723 has an active-high RESET push-pull
output. The LM3724 has an active-low open-drain RESET# output.
Three standard reset voltage options are available, suitable for monitoring 5V, 3.3V, and 2.5V supply
voltages. Additional reset voltages are also available; contact National Semiconductor for details.
With a low supply current of only 6µA, the LM3722/LM3723/LM3724 are ideal for use in portable equipment.
The LM3722/LM3723/LM3724 are available in the 5-pin SOT23 package.
Features
●
●
●
Precise monitoring of 2.5V, 3.3V, and 5V supply voltages
Fully specified over temperature Industrial: -40°C to +85°C Extended: -40°C to +125°C
100 ms minimum Power-On Reset pulse width, 190 ms typical: Active-Low RESET# Output (LM3722)
Active-High RESET Output (LM3723) Active-Low RESET# Open Drain Output (LM3724)
Guaranteed RESET# Output valid for VCC >= 1V
●
●
●
●
Low Supply Current, 6µA typical
Power supply transient immunity
Compatible with MAX811/812 applications
Applications
●
●
●
●
●
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Portable/Battery-Powered Equipment
[Information as of 5-Aug-2002]
Search
Design
Purchasing
Quality
Company
Home
About Languages . Website Guide . About "Cookies" . National is QS 9000 Certified . Privacy/Security Statement .
Contact Us . Site Terms & Conditions of Use . Copyright 2002 © National Semiconductor Corporation . My Preferences .
Feedback
See Wireless Products
Products > Analog - Regulators > Regulator Control & Supervisory Function > LM3724
LM3724 Product Folder
5-Pin Microprocessor Reset Circuits
Generic P/N 3724
General
Description
Package
& Models
Samples
& Pricing
Features
Datasheet
Parametric Table
Parametric Table
Multiple Output Capability
On/Off Pin
No
Yes
Yes
1
Output Current, max
Output Voltage (Volt)
Adjustable Output
20 mA
-
Error Flag
Yes
-
Input Voltage, min (Volt)
Input Voltage, max (Volt)
Switching Frquency (Hz)
Adjustable Switching
Sync Pin
6
No
No
Datasheet
Title
Size in Kbytes Date
Receive via Email
Download
View Online
View Online Download Receive via Email
5-Jun-01
LM3722 LM3723 LM3724 5-Pin
Microprocessor Reset Circuits
219 Kbytes
If you have trouble printing or viewing PDF file(s), see Printing Problems.
Package Availability, Models, Samples & Pricing
Budgetary
Pricing
Samples &
Electronic
Orders
Std
Pack
Size
Package
Models
Package
Marking
Part Number
Status
Type Pins MSL
SPICE IBIS
Qty $US each
Samples
reel
of
1000
R64B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3724EM5-2.32
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
Buy Now
Samples
reel
of
1000
R63B
¢Z¢1¢T
LM3724EM5-3.08
LM3724EM5-4.63
Buy Now
Samples
reel
of
1000
R62B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R50B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
LM3724IM5-2.32
LM3724IM5-3.08
LM3724IM5-4.63
5
5
5
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
1K+
1K+
1K+
$0.8000
$0.8000
$0.8000
Buy Now
Samples
reel
of
1000
R53B
¢Z¢1¢T
Buy Now
Samples
reel
of
1000
R55B
¢Z¢1¢T
Buy Now
reel
of
3000
R64B
¢Z¢1¢T
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
MSL
MSL
MSL
MSL
MSL
MSL
LM3724EM5X-2.32
LM3724EM5X-3.08
LM3724EM5X-4.63
LM3724IM5X-2.32
LM3724IM5X-3.08
LM3724IM5X-4.63
LM3724E2.32 MDC
LM3724E3.08 MDC
LM3724E4.63 MDC
LM3724I2.32 MDC
LM3724I3.08 MDC
LM3724I4.63 MDC
LM3724E2.32 MWC
LM3724E3.08 MWC
5
5
5
5
5
5
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1K+
1K+
1K+
1K+
1K+
1K+
$0.9500
$0.9500
$0.9500
$0.8000
$0.8000
$0.8000
reel
of
3000
R63B
¢Z¢1¢T
reel
of
3000
R62B
¢Z¢1¢T
reel
of
3000
R50B
¢Z¢1¢T
reel
of
3000
R53B
¢Z¢1¢T
reel
of
3000
R55B
¢Z¢1¢T
tray
of
N/A
Samples
Samples
Samples
Samples
Samples
Samples
Die
-
-
-
-
-
-
-
-
tray
of
N/A
Die
Die
Die
Die
Die
tray
of
N/A
tray
of
N/A
tray
of
N/A
tray
of
N/A
wafer jar
of
Wafer
Wafer
N/A
wafer jar
of
N/A
wafer jar
of
Wafer
Wafer
Wafer
Wafer
LM3724E4.63 MWC
LM3724I2.32 MWC
LM3724I3.08 MWC
LM3724I4.63 MWC
Full production N/A
Full production N/A
Full production N/A
Full production N/A
N/A
N/A
N/A
N/A
-
-
-
-
N/A
wafer jar
of
N/A
wafer jar
of
N/A
wafer jar
of
N/A
General Description
The LM3722/LM3723/LM3724 microprocessor supervisory circuits monitor the power supplies in
microprocessor and digital systems. They provide a reset to the microprocessor during power-up, power-
down, brown-out conditions, and manual reset.
The LM3722/LM3723/LM3724 asserts a reset signal whenever the supply decreases below the factory-
programmed reset threshold for at least 100 ms. The reset signal remains asserted for 190 ms after VCC
rises above the threshold.
The LM3722 has an active-low RESET# push-pull output. The LM3723 has an active-high RESET push-pull
output. The LM3724 has an active-low open-drain RESET# output.
Three standard reset voltage options are available, suitable for monitoring 5V, 3.3V, and 2.5V supply
voltages. Additional reset voltages are also available; contact National Semiconductor for details.
With a low supply current of only 6µA, the LM3722/LM3723/LM3724 are ideal for use in portable equipment.
The LM3722/LM3723/LM3724 are available in the 5-pin SOT23 package.
Features
●
●
●
Precise monitoring of 2.5V, 3.3V, and 5V supply voltages
Fully specified over temperature Industrial: -40°C to +85°C Extended: -40°C to +125°C
100 ms minimum Power-On Reset pulse width, 190 ms typical: Active-Low RESET# Output (LM3722)
Active-High RESET Output (LM3723) Active-Low RESET# Open Drain Output (LM3724)
Guaranteed RESET# Output valid for VCC >= 1V
●
●
●
●
Low Supply Current, 6µA typical
Power supply transient immunity
Compatible with MAX811/812 applications
Applications
●
●
●
●
●
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Portable/Battery-Powered Equipment
[Information as of 5-Aug-2002]
Search
Design
Purchasing
Quality
Company
Home
About Languages . Website Guide . About "Cookies" . National is QS 9000 Certified . Privacy/Security Statement .
Contact Us . Site Terms & Conditions of Use . Copyright 2002 © National Semiconductor Corporation . My Preferences .
Feedback
相关型号：
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IC 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5, SOT-23, 5 PIN, Power Management Circuit
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LM3724IM5-4.63/NOPB
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