MAX6453 [MAXIM]
uP Supervisors with Separate VCC Reset and Manual Reset Outputs; UP监事与独立的VCC复位和手动复位输出
| 型号： | MAX6453 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | uP Supervisors with Separate VCC Reset and Manual Reset Outputs |
| 文件： | 总10页 (文件大小：190K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2637; Rev 1; 4/03
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
General Description
Features
o Precision Factory-Set Reset Thresholds From
The MAX6453–MAX6456 are low-power, dual-voltage
µP supervisors featuring separate V
reset and manu-
CC
1.6V to 4.6V
al reset outputs. The dual outputs support both soft-
system reset (interrupt) and hard-system reset (reboot)
functions. The reset output asserts when any of the
monitored voltages falls below its specified threshold
and remains asserted for the reset timeout (140ms min)
after all voltages exceed their respective reset thresh-
olds. All devices are offered with nine factory-fixed
reset thresholds for monitoring primary system voltages
o Adjustable Threshold to Monitor Voltages Down
to 0.63V
o Manual Reset Input with Extended 3.36s Setup
Period
o Immune to Short Voltage Transients
o Low 6µA Supply Current
(V ) from 1.8V to 5V and an adjustable reset input for
CC
monitoring a secondary system voltage down to 0.63V.
o Guaranteed Valid Reset Down to V
= 1.0V
CC
Each device has a manual reset input, a V
reset out-
CC
o Active-Low RESET (Push-Pull or Open-Drain)
put, and a manual reset output. The MAX6453/
MAX6454 manual reset output asserts when the manual
reset input is low. It remains asserted for the manual
reset timeout period (140ms min) after the manual reset
input transitions high. The MAX6453/MAX6354 manual
reset input controls only the manual reset output and
Outputs
o 140ms (min) Reset Timeout Period
o Small SOT Package
Ordering Information
does not affect the V
reset output.
CC
The manual reset input of the MAX6455/MAX6456 con-
trols both the manual reset and V reset outputs. When
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
CC
MAX6453UT_ _S-T
MAX6454UT_ _S-T
MAX6455UT_ _S-T
MAX6456UT_ _S-T
the manual reset input is low for less than 3.3s (typ), only
the manual reset output asserts and remains asserted for
the manual reset timeout period (140ms min) after the
manual reset input transitions high. If the manual reset
input is low for at least 3.3s (typ), the reset output also
asserts and remains asserted for the reset timeout peri-
od (140ms min) after the manual reset input transitions
high. This enhanced feature allows the implementation of
a soft/hard-system reset combination.
Note: The “_” is a placeholder for the threshold voltage level of
the devices. A desired threshold level is set by the part num-
ber suffix found in Table 1. All devices are available in tape-
and-reel only. There is a 2500-piece minimum order increment
for standard versions (Table 2). Sample stock is typically held
on standard versions only. Nonstandard versions require a
minimum order increment of 10,000 pieces. Contact factory for
availability.
The MAX6453/MAX6455 have active-low push-pull
reset and manual reset outputs, and the MAX6454/
MAX6456 have active-low open-drain reset and manual
reset outputs. All devices are available in small SOT23-
6 packages and are fully specified over the extended
temperature range (-40°C to +85°C).
Selector Guide appears at end of data sheet.
Pin Configurations
TOP VIEW
Applications
Set-Top Boxes
Consumer Electronics
DVD Players
RESET
GND
1
2
3
6
5
4
MR
RESET
GND
1
2
3
6
5
4
MR
Modems
MAX6453
MAX6454
MAX6455
MAX6456
RSTIN
RSTIN
MP3 Players
Industrial Equipment
Automotive
MROUT
V
MROUT
V
CC
CC
Medical Devices
SOT23-6
SOT23-6
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND)
Operating Teꢀperature Range .......................... -40°C to +85°C
Junction Teꢀperature......................................................+150°C
Storage Teꢀperature Range.............................-65°C to +150°C
Lead Teꢀperature (soldering, 10s) .................................+300°C
V
CC
..........................................................................-0.3V to +6V
Open-Drain RESET, MROUT....................................-0.3V to +6V
Push-Pull RESET, MROUT..........................-0.3V to (V + 0.3V)
CC
MR, RSTIN ...............................................................-0.3V to +6V
Input Current, All Pins....................................................... 20ꢀA
Continuous Power Dissipation (T = +70°C)
A
6-Pin SOT23 (derate 8.7ꢀW/°C above +70°C).............696ꢀW
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
= 1.0V to 5.5V, T = -40°C to +85°C, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)
CC
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
5.5
UNITS
Operating Voltage Range
V
1.0
V
CC
V
V
= 5.5V, no load
7
20
CC
CC
V
V
Supply Current
Reset Threshold
I
µA
CC
CC
= 3.6V, no load
6
16
46
44
31
29
26
23
22
17
16
4.50
4.25
3.00
2.85
2.55
2.25
2.12
1.62
1.52
4.63
4.38
3.08
2.93
2.63
2.32
2.19
1.67
1.58
60
4.75
4.50
3.15
3.00
2.70
2.38
2.25
1.71
1.62
V
V
CC
TH
Reset Threshold Teꢀpco
Reset Threshold Hysteresis
ppꢀ/°C
2 × V
ꢀV
TH
T
T
= 0°C to +85°C
0.615
0.610
0.630
0.645
0.650
A
A
RSTIN Threshold
V
V
TH-RSTIN
= -40°C to +85°C
RSTIN Threshold Hysteresis
RSTIN Input Current
V
2.5
ꢀV
nA
µs
HYST
I
-25
+25
280
RSTIN
RSTIN to Reset Output Delay
Reset Tiꢀeout Period
V
V
falling at 1ꢀV/µs
15
210
20
RSTIN
t
RP
140
ꢀs
µs
V
to RESET Output Delay
t
falling at 1ꢀV/µs
CC
CC
RD
MR Miniꢀuꢀ Setup Period
(Pulse Width)
t
MR to MROUT
1
µs
MR
MR Miniꢀuꢀ Input Pulse
MR Glitch Rejection
RESET asserted, MAX6455/MAX6456
2.24
3.36
100
200
210
4.48
280
s
ns
ns
ꢀs
MR to MROUT Delay
Manual Reset Tiꢀeout Period
t
140
MRP
2
_______________________________________________________________________________________
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
ELECTRICAL CHARACTERISTICS (continued)
(V
= 1.0V to 5.5V, T = -40°C to +85°C, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)
CC
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MR to V
Pullup Iꢀpedance
25
50
75
kΩ
CC
V
≥ 1.00V, I
= 50µA, outputs
CC
SINK
0.3
0.3
0.3
0.4
asserted
V
≥ 1.20V, I
= 100µA, outputs
= 1.2ꢀA, outputs
= 3.2ꢀA, outputs
CC
SINK
asserted
RESET, MROUT Output Low
(Open Drain or Push-Pull)
V
V
OL
V
≥ 2.55V, I
CC
SINK
asserted
V
≥ 4.25V, I
CC
SINK
asserted
V
≥ 1.80V, I
= 200µA,
= 500µA,
= 800µA,
CC
SOURCE
0.8 × V
0.8 × V
0.8 × V
CC
CC
CC
outputs deasserted
RESET, MROUT Output High
(Push-Pull)
V
CC
≥ 3.15V, I
SOURCE
V
V
OH
outputs deasserted
V
≥ 4.75V, I
CC
SOURCE
outputs deasserted
RESET, MROUT Output
Open-Drain Leakage Current
I
Outputs deasserted
1
µA
LKG
MR Input Low Voltage
MR Input High Voltage
V
0.3 × V
V
V
IL
CC
V
0.7 × V
IH
CC
Note 1: Devices production tested at 25°C. Overteꢀperature liꢀits are guaranteed by design.
_______________________________________________________________________________________
3
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Typical Operating Characteristics
(V
= 3.3V, T = +25°C, unless otherwise noted.)
CC
A
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
250
200
150
100
50
9
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
T = +85°C
A
8
T = +25°C
A
7
6
5
4
3
2
1
0
RESET OCCURS
ABOVE THE CURVE
T = -40°C
A
V
= 4.4V
TH
0
0
200
400
600
800
1000
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
-40
-15
10
35
60
85
RESET THRESHOLD OVERDRIVE (mV)
TEMPERATURE (°C)
NORMALIZED V RESET THRESHOLD
CC
V
TO RESET DELAY
RSTIN TO RESET DELAY
vs. TEMPERATURE (RSTIN FALLING)
CC
vs. TEMPERATURE
vs. TEMPERATURE
1.03
1.02
1.01
1.00
0.99
0.98
0.97
24.0
23.6
23.2
22.8
22.4
22.0
21.6
21.2
20.8
20.4
20.0
24.0
23.6
23.2
22.8
22.4
22.0
21.6
21.2
20.8
20.4
20.0
V
FALLING AT 1mV/µs
RSTIN FALLING AT 1mV/µs
CC
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MANUAL RESET TO MROUT AND
RESET DELAY (MAX6455/MAX6456)
V
TO RESET DELAY
CC
MAX6453 toc07
MAX6453 toc08
V
= 5V
CC
V
= 4.5V
CC
MR (5V/div)
V
= 4.392V
TH
V
= 4.3V
CC
MROUT (5V/div)
RESET (5V/div)
V
(100mV/div)
CC
RESET (2V/div)
TIME (1s/div)
TIME (100µs/div)
4
_______________________________________________________________________________________
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Pin Description
PIN
NAME
FUNCTION
MAX6453
MAX6454
MAX6455
MAX6456
Active-Low Push-Pull or Open-Drain Output. RESET changes froꢀ high to low when
V
or RSTIN drops below its selected reset threshold. RESET reꢀains low for the
CC
1
—
140ꢀs (ꢀin) reset tiꢀeout period after all ꢀonitored power-supply inputs exceed their
selected reset thresholds. MR does not affect RESET output. For open-drain outputs,
connect to an external pullup resistor.
RESET
Active-Low Push-Pull or Open-Drain Output. RESET changes froꢀ high to low when
V
or RSTIN drops below its selected reset threshold. RESET reꢀains low for the
CC
140ꢀs (ꢀin) reset tiꢀeout period after all ꢀonitored power-supply inputs exceed their
selected reset thresholds. RESET changes froꢀ high to low after MR input is held low
for the 3.36s (typ) setup period and deasserts 140ꢀs (ꢀin) after MR deasserts. For
open-drain outputs, connect to an external pullup resistor.
—
1
2
3
2
3
GND
Ground
Manual Reset Push-Pull or Open-Drain Output. MROUT asserts iꢀꢀediately after MR is
pulled low. MROUT reꢀains low for 140ꢀs (ꢀin) after MR is deasserted. For open-
drain outputs, connect to an external pullup resistor.
MROUT
V
Voltage Input. Power supply and input for the priꢀary ꢀicroprocessor voltage
CC
4
5
4
5
V
CC
reset ꢀonitor.
Reset Input. High-iꢀpedance input to the adjustable reset coꢀparator. Connect RSTIN
to the center point of an external resistor divider to set the threshold of the externally
ꢀonitored voltage.
RSTIN
Manual Reset Input. Internal 50kΩ pullup to V . Pull MR low to iꢀꢀediately assert
MROUT. MR does not affect RESET output.
CC
6
—
6
MR
Manual Reset Input. Internal 50kΩ pullup to V . Pull MR low to iꢀꢀediately assert
CC
MROUT. RESET changes froꢀ high to low after MR input is held low for the 3.36s (typ)
—
setup period.
_______________________________________________________________________________________
5
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Manual Reset
The MAX6453/MAX6454 contain a ꢀanual reset output
(MROUT) that asserts low iꢀꢀediately after driving MR
low and reꢀains low for the reset tiꢀeout period after
MR goes high (Figure 1). The pushbutton ꢀanual reset
has no effect on the RESET output. MROUT output can
be used to drive an NMI (nonꢀaskable interrupt) on the
processor to save valuable data.
MR
210ms
MROUT
The MAX6455/MAX6456’s MROUT is asserted iꢀꢀedi-
ately upon driving MR low. Driving MR low for longer
than the 3.36s (typ) setup period asserts RESET. When
MR is deasserted, MROUT and RESET reꢀain asserted
low for the reset tiꢀeout period after MR goes high
(Figure 2).
Figure 1. MAX6453/MAX6454 Timing Diagram
Detailed Description
Reset Output
The reset output is typically connected to the reset
input of a ꢀicroprocessor (µP). A µP’s reset input starts
or restarts the µP in a known state. The MAX6453–
MAX6456 µP supervisory circuits provide the reset
logic to prevent code-execution errors during power-
up, power-down and brownout conditions (see the
Typical Operating Circuit).
Adjustable Input Voltage (RSTIN)
The MAX6453–MAX6456 ꢀonitor the voltage on RSTIN
using an adjustable reset threshold set with an external
resistor voltage divider (Figure 3). Use the following for-
ꢀula to calculate the externally ꢀonitored voltage
(V
):
MON-TH
V
= V
✕ (R1 +R2) / R2
TH-RSTIN
MON-TH
RESET changes froꢀ high to low whenever the ꢀoni-
where V
is the desired reset threshold voltage
is the reset input threshold (0.63V).
MON_TH
tored voltage (RSTIN or V ) drops below the reset
CC
RSTIN
and V
TH-RSTIN
threshold voltages. When V
and V
exceed their
CC
Resistors R1 and R2 can have very high values to ꢀini-
ꢀize current consuꢀption due to low leakage currents.
Set R2 to soꢀe conveniently high value (250kΩ, for
exaꢀple) and calculate R1 based on the desired reset
threshold voltage, using the following forꢀula:
respective reset threshold voltages, RESET reꢀains low
for the reset tiꢀeout period, and then goes high. RESET
changes froꢀ high to low after MR input is held low for
the 3.36s (typ) setup period and deasserts 140ꢀs (ꢀin)
after MR deasserts.
R1 = R2 ✕ (V
/ V - 1)Ω
TH
MON_TH
RESET is guaranteed to be in the proper output logic
state for V
inputs ≥ 1V. For applications requiring valid
CC
reset logic when V
is less than 1V, see the Ensuring a
CC
Valid RESET Output Down to V
= 0V section.
CC
LONG SETUP PERIOD, 3.36s
MR
210ms
MROUT
RESET
Figure 2. MAX6455/MAX6456 Timing Diagram
6
_______________________________________________________________________________________
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Generally, the pullup resistor connected to the RESET
connects to the supply voltage being ꢀonitored at the
V
V
CC
MON_TH
IC’s V
pin. However, soꢀe systeꢀs ꢀight use the
CC
open-drain output to level-shift froꢀ the ꢀonitored sup-
ply to reset circuitry powered by soꢀe other supply
(Figure 5). Keep in ꢀind that as the supervisor’s V
CC
R1
R2
MAX6453
MAX6455
decreases toward 1V, so does the IC’s ability to sink
current at RESET (RESET is pulled high as V decays
CC
RSTIN
GND
V
CC
toward 0). The voltage where this occurs depends on
the pullup resistor value and the voltage to which it is
connected.
Ensuring a Valid RESET Down to V
= 0V
CC
RESET
(Push-Pull RESET)
When V
falls below 1V, RESET current-sinking capa-
CC
bilities decline drastically. The high-iꢀpedance CMOS-
logic inputs connected to RESET can drift to
undeterꢀined voltages. This presents no probleꢀ in
ꢀost applications, because ꢀost µPs and other circuit-
V
= 0.63 x (R1 + R2) / R2
MON_TH
ry do not operate with V
below 1V.
CC
Figure 3. Calculating The Monitored Threshold Voltages
In applications where RESET ꢀust be valid down to 0V,
add a pulldown resistor between RESET and GND for
the push/pull outputs. The resistor sinks any stray leak-
age currents, holding RESET low (Figure 6). The value
of the pulldown resistor is not critical; 100kΩ is large
enough not to load RESET and sꢀall enough to pull
RESET to ground. The external pulldown cannot be
used with the open-drain reset outputs.
Applications Information
Interrupt Before Reset
To ꢀiniꢀize data loss and speed systeꢀ recovery/test,
ꢀany applications interrupt the processor or reset only
portions of the systeꢀ before a processor hard reset is
asserted. The extended setup tiꢀe of the MAX6455/
MAX6456 MR input allows the saꢀe pushbutton (Figure
4) to control both the interrupt and hard reset functions.
If the pushbutton is closed for less than 3.36s (typ), the
processor is only interrupted (MROUT). If the systeꢀ
still does not respond properly, the pushbutton can be
closed for the full extended setup period (3.36s typ) to
hard reset the processor (RESET). If desired, connect a
LED to the RESET output to turn off (or on) to signify
when the pushbutton is closed long enough for a hard
reset (the saꢀe LED can be used as the front panel
power-on display).
Transient Immunity
In addition to issuing a reset to the µP during power-up,
power-down and brownout conditions, these supervisors
are relatively iꢀꢀune to short duration falling transients
(glitches). The graph Maxiꢀuꢀ Transient Duration vs.
Reset Threshold Overdrive in the Typical Operating
Characteristics section shows this relationship.
The area below the curves of the graph is the region in
which these devices typically do not generate a reset
pulse. This graph was generated using a negative
going pulse applied to V , starting above the actual
CC
reset threshold (V ) and ending below it by the ꢀagni-
TH
tude indicated (reset-threshold overdrive). As the ꢀag-
Interfacing to Other Voltages
for Logic Compatibility
nitude of the transient increases (V
goes further
CC
below the reset threshold), the ꢀaxiꢀuꢀ allowable
pulse width decreases. Typically, a V transient that
The open-drain RESET output can be used to interface
to a µP with other logic levels. As shown in Figure 5, the
open-drain output can be connected to voltages froꢀ 0
to 6V.
CC
goes 100ꢀV below the reset threshold and lasts 20µs
or less does not cause a reset pulse to be issued.
_______________________________________________________________________________________
7
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
+3.3V
3.3V
5V
+1.5V
CORE SUPPLY
RESET
I/O
SUPPLY
V
RESET
CC
V
V
CC
CC
MAX6455
RSTIN
GND
µP
100kΩ
LED
MAX6454
MAX6456
µP
NMI
MROUT
MR
RESET
RESET
GND
GND
PUSHBUTTON SWITCH
CLOSE FOR IMMEDIATE SYSTEM INTERRUPT
CLOSE FOR >3.36s FOR SYSTEM RESET
Figure 5. Interfacing to Other Voltage Levels
Figure 4. Interrupt Before Reset Application Circuit
Functional Diagram
V
CC
MAX6453–
MAX6456
V
CC
V
CC
RESET
RESET
TIMOUT PERIOD
(210ms typ)
MAX6453
MAX6455
RSTIN
RESET
MR-TO-RESET
SETUP PERIOD
(3.36s typ)
V
CC
100kΩ
MAX6455/MAX6456
GND
0.63V
1.23V
MROUT
TIMOUT PERIOD
(210ms typ)
MROUT
V
CC
GND
MR
Figure 6. Ensuring RESET Valid to V
= 0
CC
8
_______________________________________________________________________________________
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Table 1. Reset Voltage Threshold
Table 2. Standard Versions Table
PART NO.
SUFFIX
( _ _ )
V
NOMINAL
CC
VOLTAGE
TOP
MARK
TOP
MARK
PART
PART
THRESHOLD (V)
MAX6453UT16S
MAX6453UT23S
MAX6453UT26S
MAX6453UT29S
MAX6453UT46S
MAX6454UT16S
MAX6454UT23S
MAX6454UT26S
MAX6454UT29S
MAX6454UT46S
ABOG
ABOH
ABOI
MAX6455UT16S
MAX6455UT23S
MAX6455UT26S
MAX6455UT29S
MAX6455UT46S
MAX6456UT16S
MAX6456UT23S
MAX6456UT26S
MAX6456UT29S
MAX6456UT46S
ABOL
ABOM
ABON
ABOO
ABER
ABES
ABOT
ABOU
ABOV
ABOW
46
44
31
29
26
23
22
17
16
4.625
4.375
3.075
2.925
2.625
2.313
2.188
1.665
1.575
ABOJ
ABOK
ABOP
ABEQ
ABOQ
ABOR
ABOS
Selector Guide
MROUT AND RESET
PUSH-PULL OUTPUT
MROUT AND RESET
OPEN-DRAIN OUTPUT
PART
MR TO RESET DELAY
MR ASSERTION
MAX6453
MAX6454
MAX6455
MAX6456
—
MROUT
ꢀ
—
ꢀ
—
ꢀ
—
MROUT
3.36s
3.36s
MROUT and RESET
MROUT and RESET
—
ꢀ
—
*Other timing options may be available. Contact factory for availability.
Typical Operating Circuit
Chip Information
TRANSISTOR COUNT: 1384
PROCESS: BiCMOS
+3.3V
+1.5V
CORE SUPPLY
RESET
I/O
SUPPLY
V
RESET
CC
MAX6453
RSTIN
µP
NMI
MROUT
MR
GND
GND
_______________________________________________________________________________________
9
µP Supervisors with Separate V Reset and
CC
Manual Reset Outputs
Package Information
(The package drawing(s) in this data sheet ꢀay not reflect the ꢀost current specifications. For the latest package outline inforꢀation,
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, SOT-23, 6L
1
21-0058
F
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxiꢀ Integrated Products
Printed USA
is a registered tradeꢀark of Maxiꢀ Integrated Products.
相关型号：
MAX6453UT16S+
Power Supply Support Circuit, Adjustable, 1 Channel, +1.575VV, BICMOS, PDSO6, LEAD FREE, SOT-23, 6 PIN
MAXIM
MAX6453UT16S-T
Power Supply Support Circuit, Adjustable, 1 Channel, +1.58VV, BICMOS, PDSO6, SOT-23, 6 PIN
MAXIM
©2020 ICPDF网 联系我们和版权申明