MAX803MEXR/V+ [MAXIM]
Power Supply Support Circuit,;
| 型号： | MAX803MEXR/V+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Power Supply Support Circuit, 微处理器 复位电路 |
| 文件： | 总8页 (文件大小：136K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0344; Rev 7; 2/10
3-Pin Microprocessor Reset Circuits
39J,AX810LMRST/Z
General Description
____________________________Features
♦ Precision Monitoring of +2.5V, +3V, +3.3V, and
The MAX803/MAX809/MAX810 are microprocessor (µP)
supervisory circuits used to monitor the power supplies
in µP and digital systems. They provide excellent circuit
reliability and low cost by eliminating external compo-
nents and adjustments when used with +5V, +3.3V,
+3.0V, or +2.5V powered circuits.
+5V Power-Supply Voltages
♦ Fully Specified Over Temperature
♦ Available in Three Output Configurations
Open-Drain RESET Output (MAX803)
Push-Pull RESET Output (MAX809)
Push-Pull RESET Output (MAX810)
♦ 140ms min Power-On Reset Pulse Width
♦ 12µA Supply Current
♦ Guaranteed Reset Valid to VCC = +1V
♦ Power Supply Transient Immunity
♦ No External Components
These circuits perform a single function: they assert a
reset signal whenever the V
supply voltage declines
CC
below a preset threshold, keeping it asserted for at
least 140ms after V has risen above the reset thresh-
CC
old. Reset thresholds suitable for operation with a vari-
ety of supply voltages are available.
The MAX803 has an open-drain output stage, while the
MAX809/MAX810 have push-pull outputs. The
MAX803’s open-drain RESET output requires a pullup
resistor that can be connected to a voltage higher than
♦ 3-Pin SC70 and SOT23 Packages
Ordering Information
V
CC
. The MAX803/MAX809 have an active-low RESET
output, while the MAX810 has an active-high RESET
output. The reset comparator is designed to ignore fast
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +105°C
-40°C to +105°C
-40°C to +125°C
-40°C to +125°C
-40°C to +105°C
-40°C to +105°C
PIN-PACKAGE
MAX803_EXR-T
MAX803_EXR+T
MAX809_EXR-T
MAX809_EXR+T
MAX809_EUR-T
MAX809_EUR+T
MAX810_EXR-T
MAX810_EXR+T
MAX810_EUR-T
MAX810_EUR+T
3 SC70
transients on V , and the outputs are guaranteed to
CC
3 SC70
be in the correct logic state for V
down to 1V.
CC
3 SC70
Low supply current makes the MAX803/MAX809/
MAX810 ideal for use in portable equipment. The
MAX803 is available in a 3-pin SC70 package, and the
MAX809/MAX810 are available in 3-pin SC70 or SOT23
packages.
3 SC70
3 SOT23
3 SOT23
3 SC70
Applications
3 SC70
Computers
Controllers
3 SOT23
3 SOT23
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
Note: These parts are offered in 2.5k reels, and must be
ordered in 2.5k increments. Insert the desired suffix letter from
the Selector Guide into the blank to complete the part number.
All versions of these products may not be available at the time
of announcement. Contact factory for availability.
Devices are available in both leaded and lead-free packaging.
+Denotes a lead(Pb)-free/RoHS-compliant package.
Typical Operating Circuit
Pin Configuration
TOP VIEW
V
CC
V
1
2
GND
V
CC
CC
R
*
PULLUP
MAX803
MAX809
μP
MAX803
MAX809
MAX810
V
CC
3
RESET
INPUT
RESET
RESET (RESET)
GND
GND
SC70-3/SOT23-3
( ) ARE FOR MAX810.
MAX803 AVAILABLE IN SC70-3 ONLY.
*MAX803 ONLY
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
3-Pin Microprocessor Reset Circuits
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
Continuous Power Dissipation (T = +70°C)
A
V
CC
....................................................................-0.3V to +6.0V
3-Pin SC70 (derate 2.17mW/°C above +70°C)............174mW
3-Pin SOT23 (derate 4mW/°C above +70°C)...............320mW
Operating Temperature Range
RESET, RESET (push-pull) .....................-0.3V to (V
RESET (open drain)...........................................-0.3V to +6.0V
+ 0.3V)
CC
3-Pin SC70.....................................................-40°C to +125°C
3-Pin SOT23...................................................-40°C to +105°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Input Current, V ..............................................................20mA
Output Current, RESET, RESET ..........................................20mA
CC
Rate of Rise, V
............................................................100V/µs
CC
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
CC
= full range, T = -40°C to +105°C (SOT23) or T = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at T
=
A
A
A
+25°C, V
= 5V for L/M/J versions, V
= 3.3V for T/S versions, V
= 3V for R version, and V
= 2.5V for Z version.) (Note 1)
CC
CC
CC
CC
PARAMETER
SYMBOL
CONDITIONS
= 0°C to +70°C
MIN
1.0
1.2
1.2
TYP
MAX
5.5
UNITS
T
T
T
T
A
A
A
V
CC
Range
V
= -40°C to +105°C (MAX8_ _ _EUR)
= -40°C to +125°C (MAX8_ _ _EXR)
5.5
5.5
V
CC
V
CC
V
CC
V
CC
V
CC
V
CC
V
CC
V
CC
< 5.5V, MAX8_ _L/M
< 3.6V, MAX8_ _R/S/T/Z
< 5.5V, MAX8_ _L/M
< 3.6V, MAX8_ _R/S/T/Z
< 5.5V, MAX8_ _L/M
< 3.6V, MAX8_ _R/S/T/Z
< 5.5V, MAX8_ _L/M
< 3.6V, MAX8_ _R/S/T/Z
24
17
60
= -40°C
to +85°C
A
50
Supply Current (SOT23)
Supply Current (SC70)
I
I
CC
100
100
35
T
A
= +85°C
to +105°C
μA
24
17
T
A
= -40°C
to +85°C
30
CC
60
T
A
= +85°C
to +125°C
60
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
= +25°C
4.56
4.50
4.40
4.31
4.25
4.16
3.93
3.89
3.80
3.04
3.00
2.92
2.89
2.85
2.78
2.59
2.55
2.50
4.63
4.38
4.00
3.08
2.93
2.63
4.70
4.75
4.86
4.45
4.50
4.56
4.06
4.10
4.20
3.11
3.15
3.23
2.96
3.00
3.08
2.66
2.70
2.76
MAX8_ _L
= -40°C to +85°C
= -40°C to +125°C
= +25°C
MAX8_ _M
= -40°C to +85°C
= -40°C to +125°C
= +25°C
MAX809J
(SOT only)
= -40°C to +85°C
= -40°C to +125°C
= +25°C
Reset Threshold
(SOT only)
V
TH
V
MAX8_ _T
MAX8_ _S
MAX8_ _R
= -40°C to +85°C
= -40°C to +125°C
= +25°C
= -40°C to +85°C
= -40°C to +125°C
= +25°C
= -40°C to +85°C
= -40°C to +125°C
2
_______________________________________________________________________________________
39J,AX810LMRST/Z
3-Pin Microprocessor Reset Circuits
39J,AX810LMRST/Z
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= full range, T = -40°C to +105°C (SOT23) or T = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at T
=
A
A
A
+25°C, V
= 5V for L/M/J versions, V
= 3.3V for T/S versions, V
= 3V for R version, and V
= 2.5V for Z version.) (Note 1)
CC
CC
CC
CC
PARAMETER
SYMBOL
CONDITIONS
MIN
4.56
4.50
4.44
4.31
4.25
4.20
3.04
3.00
2.95
2.89
2.85
2.81
2.59
2.55
2.52
2.28
2.25
2.22
TYP
MAX
4.70
4.75
4.82
4.45
4.50
4.56
3.11
3.15
3.21
2.96
3.00
3.05
2.66
2.70
2.74
2.35
2.38
2.42
UNITS
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
= +25°C
4.63
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
MAX8_ _L
MAX8_ _M
MAX8_ _T
MAX8_ _S
MAX8_ _R
= -40°C to +85°C
= -40°C to +125°C
= +25°C
4.38
3.08
2.93
2.63
2.32
= -40°C to +85°C
= -40°C to +125°C
= +25°C
= -40°C to +85°C
= -40°C to +125°C
= +25°C
Reset Threshold
(SC70 only)
V
TH
V
= -40°C to +85°C
= -40°C to +125°C
= +25°C
= -40°C to +85°C
= -40°C to +125°C
= +25°C
MAX8_ _Z
(SC70 only)
= -40°C to +85°C
= -40°C to +125°C
Reset Threshold Tempco
30
20
ppm/°C
μs
V
CC
to Reset Delay (Note 2)
V = V to (V - 100mV)
CC TH TH
T
A
T
A
T
A
T
A
= -40°C to +85°C
= +85°C to +105°C
= -40°C to +85°C
= +85°C to +125°C
140
100
140
100
240
560
840
460
840
Reset Active Timeout Period
(SOT23)
ms
ms
240
Reset Active Timeout Period
(SC70)
V
= V min, I
= 1.2mA,
SINK
CC
TH
0.3
RESET Output Voltage Low
(push-pull active low and open-
drain active low, MAX803 and
MAX809)
MAX803R/S/T/Z, MAX809R/S/T/Z
V
V
OL
V
CC
= V min, I = 3.2mA,
TH
SINK
0.4
0.3
MAX803L/M, MAX809J/L/M
V
CC
> 1.0V, I
= 50μA
SINK
V
> V max, I
= 500μA,
CC
TH
SOURCE
0.8V
CC
MAX803R/S/T/Z, MAX809R/S/T/Z
RESET Output Voltage High
(push-pull active low MAX809)
V
V
V
OH
V
> V max, I = 800μA,
CC
TH
SOURCE
V
CC
- 1.5
MAX803L/M, MAX809J/L/M
V
CC
= V max, I
= 1.2mA,
TH
SINK
0.3
0.4
MAX810R/S/T/Z
RESET Output Voltage Low
(push-pull active high, MAX810)
V
OL
V
CC
= V max, I
= 3.2mA,
TH
SINK
MAX810L/M
_______________________________________________________________________________________
3
3-Pin Microprocessor Reset Circuits
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= full range, T = -40°C to +105°C (SOT23) or T = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at T
=
A
A
A
+25°C, V
= 5V for L/M/J versions, V
= 3.3V for T/S versions, V
= 3V for R version, and V
= 2.5V for Z version.) (Note 1)
CC
CC
CC
CC
PARAMETER
SYMBOL
CONDITIONS
1.8V < V < V min, I
MIN
0.8V
TYP
MAX
UNITS
RESET Output Voltage High
(push-pull active high, MAX810)
V
= 150μA
V
OH
CC
TH
SOURCE
CC
RESET Open-Drain Output
Leakage Current (MAX803)
(Note 3)
V
CC
> V , RESET deasserted
1
μA
TH
Note 1: Production testing done at T = +25°C; limits over temperature guaranteed by design only.
A
Note 2: RESET output for MAX803/MAX809; RESET output for MAX810.
Note 3: Guaranteed by design, not production tested.
Typical Operating Characteristics
(V
CC
= full range, T = -40°C to +105°C, unless otherwise noted. Typical values are at T = +25°C, V
= +5V for L/M/J versions,
A
A
CC
V
CC
= +3.3V for T/S versions, V
= +3V for R version, and V
= +2.5V for Z version.)
CC
CC
POWER-DOWN RESET DELAY vs.
TEMPERATURE (MAX8_ _J/L/M)
SUPPLY CURRENT vs. TEMPERATURE
(SC70 PACKAGE, NO LOAD)
POWER-DOWN RESET DELAY vs.
TEMPERATURE (MAX8_ _R/S/T/Z)
140
120
100
80
100
80
15
10
5
V
= V - V
TH CC
V
= V - V
CC
OD
OD
TH
V
OD
= 10mV
MAX8_ _L/M, V = 5V
CC
V
= 10mV
= 20mV
OD
MAX8_ _R/S/T, V = 3.3V
CC
V
= 20mV
OD
60
V
OD
MAX8_ _Z, V = 2.5V
CC
60
40
40
20
0
V
= 100mV
OD
V
OD
= 100mV
20
0
MAX8_ _L/M/R/S/T/Z, V = 1V
CC
V
OD
= 200mV
60
V
OD
= 200mV
60
0
20
TEMPERATURE (°C)
85
-20
-40
0
40
20
TEMPERATURE (°C)
85
-40
-20
0
20
40
60
85
-20
-40
0
40
TEMPERATURE (°C)
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
POWER-UP RESET TIMEOUT
vs. TEMPERATURE
1.003
250
245
240
235
230
1.002
MAX8__J/L/M
1.001
1.000
0.999
0.998
0.997
MAX8__R/S/T/Z
225
-40
20
TEMPERATURE (°C)
60
85
-20
-40
0
40
20
TEMPERATURE (°C)
60
85
-20
0
40
4
_______________________________________________________________________________________
39J,AX810LMRST/Z
3-Pin Microprocessor Reset Circuits
39J,AX810LMRST/Z
Selector Guide
TOP MARK
PART/SUFFIX
RESET THRESHOLD (V)
OUTPUT TYPE
SOT
SC70
MAX803L
MAX803M
MAX803T
MAX803S
MAX803R
MAX803Z
MAX809L
MAX809M
MAX809J
MAX809T
MAX809S
MAX809R
MAX809Z
MAX810L
MAX810M
MAX810T
MAX810S
MAX810R
MAX810Z
4.63
4.38
3.08
2.93
2.63
2.32
4.63
4.38
4.00
3.08
2.93
2.63
2.32
4.63
4.38
3.08
2.93
2.63
2.32
OPEN-DRAIN RESET
OPEN-DRAIN RESET
OPEN-DRAIN RESET
OPEN-DRAIN RESET
OPEN-DRAIN RESET
OPEN-DRAIN RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
PUSH-PULL RESET
⎯
⎯
⎯
⎯
⎯
AAZ
ABA
ABB
ABC
ABD
ABE
AAN
AAO
⎯
AAP
AAQ
AAR
AAS
AAT
AAU
AAV
AAX
AAW
AAY
⎯
AAAA
ABAA
CWAA
ACAA
ADAA
AFAA
⎯
AGAA
AHAA
AJAA
AKAA
ALAA
⎯
Detailed Description
Applications Information
A microprocessor’s (µP’s) reset input starts the µP in a
known state. The MAX803/MAX809/MAX810 assert
reset to prevent code-execution errors during power-
up, power-down, or brownout conditions. They assert a
Negative-Going V
Transients
CC
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, the MAX803/
MAX809/MAX810 are relatively immune to short-duration
reset signal whenever the V
supply voltage declines
CC
negative-going V transients (glitches).
CC
below a preset threshold, keeping it asserted for at
least 140ms after V has risen above the reset thresh-
Figure 1 shows typical transient duration vs. reset com-
parator overdrive, for which the MAX803/MAX809/
MAX810 do not generate a reset pulse. The graph was
CC
old. The MAX803 uses an open-drain output, and the
MAX809/MAX810 have a push-pull output stage.
Connect a pullup resistor on the MAX803’s RESET out-
put to any supply between 0 and 6V.
generated using a negative-going pulse applied to V
,
CC
starting 0.5V above the actual reset threshold and end-
ing below it by the magnitude indicated (reset compara-
tor overdrive). The graph indicates the maximum pulse
Pin Description
width a negative-going V
transient can have without
CC
PIN
NAME
FUNCTION
causing a reset pulse. As the magnitude of the transient
increases (goes farther below the reset threshold), the
maximum allowable pulse width decreases. Typically, for
1
GND
Ground
RESET Output remains low while V
is below the reset threshold, and for at
CC
RESET
(MAX803/
MAX809)
the MAX8__L and MAX8__M, a V
transient that goes
CC
100mV below the reset threshold and lasts 20µs or less
will not cause a reset pulse. A 0.1µF bypass capacitor
least 140ms after V
reset threshold.
rises above the
CC
2
3
mounted as close as possible to the V
additional transient immunity.
pin provides
CC
RESET Output remains high while V
is below the reset threshold, and for at
CC
RESET
(MAX810)
least 140ms after V
rises above the
CC
Ensuring a Valid Reset Output
Down to V = 0V
falls below 1V, the MAX809 RESET output
reset threshold.
CC
Supply Voltage (+5V, +3.3V, +3.0V, or
+2.5V)
When V
CC
V
CC
no longer sinks current—it becomes an open circuit.
_______________________________________________________________________________________
5
3-Pin Microprocessor Reset Circuits
Therefore, high-impedance CMOS logic inputs con-
Interfacing to µPs with
Bidirectional Reset Pins
nected to RESET can drift to undetermined voltages.
This presents no problem in most applications since
Since the RESET output on the MAX803 is open drain,
this device interfaces easily with µPs that have bidirec-
tional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output directly
to the microcontroller’s (µC’s) RESET pin with a single
pullup resistor allows either device to assert reset
(Figure 3).
most µP and other circuitry is inoperative with V
CC
below 1V. However, in applications where RESET must
be valid down to 0V, adding a pull-down resistor to
RESET causes any stray leakage currents to flow to
ground, holding RESET low (Figure 2). R1’s value is not
critical; 100kΩ is large enough not to load RESET and
small enough to pull RESET to ground.
MAX803 Open-Drain RESET Output
Allows Use with Multiple Supplies
A 100kΩ pullup resistor to V
is also recommended
CC
for the MAX810 if RESET is required to remain valid for
Generally, the pullup connected to the MAX803 will
connect to the supply voltage that is being monitored at
V
CC
< 1V.
the IC’s V
pin. However, some systems may use the
CC
open-drain output to level-shift from the monitored sup-
ply to reset circuitry powered by some other supply
(Figure 4). Note that as the MAX803’s V
decreases
CC
400
320
T
= +25°C
A
V
CC
240
160
80
MAX809
RESET
MAX8_ _J/L/M
R1
100k
GND
MAX8_ _R/S/T/Z
10
0
1
100
1000
RESET COMPARATOR OVERDRIVE, V - V (mV)
TH
CC
Figure 2. RESET Valid to V
= Ground Circuit
CC
Figure 1. Maximum Transient Duration Without Causing a
Reset Pulse vs. Reset Comparator Overdrive
+5.0V
+3.3V
V
CC
V
V
CC
CC
V
V
CC
CC
R
PULLUP
5V SYSTEM
μP
MAX803
MAX803
RESET
INPUT
MOTOROLA
68HCXX
RESET
RESET
INPUT
RESET
GND
GND
GND
GND
Figure 4. MAX803 Open-Drain RESET Output Allows Use with
Multiple Supplies
Figure 3. Interfacing to µPs with Bidirectional Reset I/O
6
_______________________________________________________________________________________
39J,AX810LMRST/Z
3-Pin Microprocessor Reset Circuits
39J,AX810LMRST/Z
below 1V, so does the IC’s ability to sink current at
RESET. Also, with any pullup, RESET will be pulled high
as V decays toward 0. The voltage where this occurs
depends on the pullup resistor value and the voltage to
which it is connected.
Chip Information
TRANSISTOR COUNT: 275 (SOT23)
CC
380 (SC70)
Package Information
Benefits of Highly Accurate
Reset Threshold
Most µP supervisor ICs have reset threshold voltages
between 5% and 10% below the value of nominal sup-
ply voltages. This ensures a reset will not occur within
5% of the nominal supply, but will occur when the sup-
ply is 10% below nominal.
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
3 SC70
X3-2
U3-1
21-0075
21-0051
When using ICs rated at only the nominal supply 5%,
this leaves a zone of uncertainty where the supply is
between 5% and 10% low, and where the reset may or
may not be asserted.
3 SOT23
The MAX8__L/T/Z use highly accurate circuitry to
ensure that reset is asserted close to the 5% limit, and
long before the supply has declined to 10% below
nominal.
_______________________________________________________________________________________
7
3-Pin Microprocessor Reset Circuits
Revision History
REVISION REVISION
DESCRIPTION
PAGES
CHANGED
NUMBER
DATE
0
12/94
Initial release.
—
Updated Ordering information, added lead-free note, and added soldering
temperature in the Absolute Maximum Ratings.
7
2/10
1, 2
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implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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39J,AX810LMRST/Z
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