MAX6805US44D1+T [MAXIM]
Power Supply Support Circuit, Fixed, 1 Channel, +4.38VV, BICMOS, PDSO4, SOT-143, 4 PIN;型号: | MAX6805US44D1+T |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | Power Supply Support Circuit, Fixed, 1 Channel, +4.38VV, BICMOS, PDSO4, SOT-143, 4 PIN 信息通信管理 光电二极管 |
文件: | 总8页 (文件大小:544K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-1946; Rev 2; 12/05
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
General Description
Features
The MAX6803/MAX6804/MAX6805 microprocessor (µP)
supervisory circuits monitor the power supplies in 2.85V
to 5.0V µP and digital systems. They increase circuit
reliability and reduce cost by eliminating external com-
ponents and adjustments. They also feature a
debounced manual reset input.
♦ Ultra-Low 0.7V Operating Supply Voltage
♦ Low 4.0µA Supply Current
♦ Precision Monitoring of 2.85V to 5.0V Power-
Supply Voltages
♦ Reset Thresholds Available from 2.63V to 4.80V,
in Approximately 100mV Increments
♦ Debounced Manual Reset Input
These devices perform a single function: they assert a
reset signal whenever the V
supply voltage declines
CC
below a preset threshold or whenever manual reset is
asserted. Reset remains asserted for a preset timeout
♦ Fully Specified over Temperature
period after V
has risen above the reset threshold or
CC
♦ Three Power-On Reset Timeout Periods Available
(1ms min, 20ms min, 100ms min)
♦ Low Cost
after manual reset is deasserted. The only difference
among the three devices is their output. The MAX6804
(push/pull) and MAX6805 (open-drain) have an active-
low RESET output, while the MAX6803 (push/pull) has
an active-high RESET output. The MAX6803/MAX6804
♦ Three Available Output Structures: Push/Pull
RESET, Push/Pull RESET, Open-Drain RESET
are guaranteed to be in the correct state for V
down
CC
♦ Guaranteed RESET/RESET Valid to V
(MAX6803/MAX6804)
= 0.7V
to 0.7V. The MAX6805 is guaranteed to be in the cor-
rect state for V down to 1.0V.
CC
CC
The reset comparator in these ICs is designed to ignore
♦ Power-Supply Transient Immunity
fast transients on V . Reset thresholds are factory-
CC
♦ No External Components Required
♦ 4-Pin SOT143 Package
trimmable between 2.63V and 4.80V, in approximately
100mV increments. These devices are available with a
1ms min, 20ms min, or 100ms min reset timeout period.
Ideal for space-critical applications, the MAX6803/
MAX6804/MAX6805 come packaged in a 4-pin
SOT143. For a lower threshold voltage version, see the
MAX6335/MAX6336/MAX6337.
♦ Pin Compatible with MAX811/MAX812 and
MAX6314/MAX6315
Ordering Information
Applications
Computers
PART*
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
4 SOT143
MAX6803US_ _D_-T
MAX6804US_ _D_-T
MAX6805US_ _D_-T
Controllers
4 SOT143
Intelligent Instruments
Critical µP/µC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
4 SOT143
*These devices are available in factory-set V
reset thresh-
CC
olds from 2.63V to 4.80V, in approximately 0.1V increments.
Choose the desired reset threshold suffix from Table 1 and
insert it in the blanks following “US” in the part number.
Factory-programmed reset timeout periods are also available.
Insert the number corresponding to the desired nominal reset
timeout period (1 = 1ms min, 2 = 20ms min, 3 = 100ms min) in
the blank following “D” in the part number. There are 15 stan-
dard versions with a required order increment of 2500 pieces.
Sample stock is generally held on the standard versions only
(see Selector Guide). Contact the factory for availability of non-
standard versions (required order increment is 10,000 pieces).
All devices available in tape-and-reel only.
Typical Operating Circuit and Pin Configuration appear
at end of data sheet.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Selector Guide appears at end of data sheet.
________________________________________________________________ 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.
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
Continuous Power Dissipation (T = +70°C)
A
V
......................................................................-0.3V to +6V
4-Pin SOT143 (derate 4mW/°C above +70°C)............320mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
CC
Push/Pull RESET or RESET, MR ............-0.3V to (V
Open-Drain RESET ..............................................-0.3V to +6V
+ 0.3V)
CC
Input Current (V ).............................................................20mA
Output Current (RESET, RESET).........................................20mA
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
(VCC = full range, T = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5.0V and T = +25°C, reset not
A
A
asserted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
0.7
TYP
MAX
5.5
5.5
5.5
5.5
10
UNITS
MAX6803/MAX6804
T
T
= 0°C to +125°C
A
MAX6805
1.0
Supply Voltage Range
(Note 1)
V
V
CC
MAX6803/MAX6804
MAX6805
0.78
1.2
= -40°C to +125°C
A
V
V
= +3.0V
= +5.0V
4
5
CC
CC
Supply Current
Reset Threshold
I
No load
µA
V
CC
12
V
V
TH
+ 1.8%
TH
T
= +25°C
V
V
A
TH
TH
- 1.8%
MAX680_US_ _D_-T,
Table 1
V
TH
V
V
TH
+ 3%
TH
T = -40°C to +125°C
A
- 3%
V
Falling Reset Delay
V
falling at 10V/ms
CC
30
µs
CC
MAX680_US_ _D1-T
MAX680_US_ _D2-T
MAX680_US_ _D3-T
1
20
100
1
1.5
30
2
Reset Active Timeout Period
t
40
ms
RP
150
200
MR Minimum Pulse Width
MR Glitch Immunity
MR Reset Delay
µs
ns
µs
50
0.1
✕
V
0.3
V
CC
IL
MR Input Voltage
V
✕
V
0.7
V
CC
IH
MR Pullup Resistance
12
20
30
0.4
0.3
0.4
kΩ
I
I
I
= 50µA, V
≥ 1.0V
≥ 2.5V
SINK
SINK
SINK
CC
RESET Output Low Voltage
(MAX6804/MAX6805)
Reset
asserted
V
V
V
= 1.2mA, V
= 3.2mA, V
OL
CC
≥ 4.25V
CC
✕
I
= 500µA, V ≥ 3.0V
0.8
V
V
SOURCE
CC
CC
CC
RESET Output High Voltage
(MAX6804)
Reset not
asserted
V
OH
✕
I
= 800µA, V ≥ 5.0V
0.8
SOURCE
CC
2
_______________________________________________________________________________________
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
ELECTRICAL CHARACTERISTICS (continued)
(VCC = full range, T = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5.0V and T = +25°C, reset not
A
A
asserted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
= 1µA, V ≥ 1.0V
MIN
TYP
MAX
UNITS
✕
I
0.8
V
CC
SOURCE
CC
Reset
asserted
✕
✕
V
I
= 200µA, V ≥ 1.8V
0.8
0.8
V
V
V
OH
SOURCE
CC
CC
CC
RESET Output Voltage
(MAX6803)
I
= 800µA, V ≥ 4.25V
CC
SOURCE
I
= 1.2mA, V ≥ 3.0V
0.3
0.4
Reset not
asserted
SINK
CC
V
V
OL
I
= 3.2mA, V ≥ 5.0V
CC
SINK
RESET Output Leakage Current
(MAX6805)
V
> V , RESET not asserted
0.5
µA
CC
TH
Note 1: All parts are production tested at T = +25°C. Over temperature limits are guaranteed by design and not production tested.
A
Note 2: I
for the MAX6803 is 100nA; I
for the MAX6804 is 100nA; I
for the MAX6805 is 50µA.
SOURCE
SINK
SINK
__________________________________________Typical Operating Characteristics
(Reset not asserted, T = +25°C, unless otherwise noted.)
A
OUTPUT-VOLTAGE LOW
vs. SUPPLY VOLTAGE
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
80
60
40
20
0
1.050
1.040
1.030
1.020
1.010
1.000
0.990
0.980
0.970
0.960
0.950
V
I
= 2.93V
TH
= 500µA
SINK
RESET
+125°C
V
= +5.0V
CC
+85°C
+25°C
-40°C
V
= +3.3V
CC
-50 -25
0
25
50
75 100 125
1.0
1.5
2.0
(V)
2.5
3.0
-50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
V
TEMPERATURE (°C)
CC
OUTPUT-VOLTAGE HIGH
vs. SUPPLY VOLTAGE
MAXIMUM TRANSIENT DURATION
vs. RESET COMPARATOR OVERDRIVE
V
CC
FALLING PROPAGATION DELAY
vs. TEMPERATURE
600
500
400
300
200
100
0
100
90
80
70
60
50
40
30
20
10
0
100
75
50
25
0
V
I
= 2.93V
TH
= 100µA
SINK
RESET ASSERTED
(MAX6803)
V
= FALLING AT 1V/ms
CC
+125°C
RESET OCCURS
+85°C
+25°C
RESET DOES
NOT OCCUR
V
= FALLING AT 10V/ms
CC
-40°C
0.1
1
10
100
1000
-50 -25
0
25
50
75 100 125
3.0
1.0
1.5
2.0
2.5
RESET COMPARATOR OVERDRIVE (mV)
TEMPERATURE (°C)
V
(V)
CC
_______________________________________________________________________________________
3
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
Pin Description
PIN
NAME
FUNCTION
MAX6804
MAX6805
1
MAX6803
1
GND
Ground
Active-Low Reset Output. RESET is asserted while V
is below the reset
CC
threshold, or while MR is asserted. RESET remains asserted for a reset
timeout period (t ) after V rises above the reset threshold or MR is
deasserted. RESET on the MAX6804 is push/pull. RESET on the MAX6805
—
2
2
RESET
RP
CC
is open-drain.
Active-High Reset Output. RESET is asserted high while V
is below the
CC
reset threshold or while MR is asserted, and RESET remains asserted for a
reset timeout period (t ) after V rises above the reset threshold or MR
—
RESET
RP
CC
is deasserted. RESET on the MAX6803 is push/pull.
Manual Reset Input. A logic low on MR asserts reset. Reset remains
3
4
3
4
MR
asserted as long as MR is low, and for the reset timeout period (t ) after
RP
MR goes high. Leave unconnected or connect to V
if not used.
CC
V
CC
Supply Voltage Input
shows the maximum pulse width that a negative-going
transient may typically have without issuing a reset
signal. As the amplitude of the transient increases, the
maximum allowable pulse width decreases.
Applications Information
V
CC
Manual Reset Input
Many µP-based products require manual reset capabil-
ity, allowing the operator, a test technician, or external
logic circuitry to initiate a reset. A logic low on MR
asserts reset. Reset remains asserted while MR is low,
and for the reset active timeout period after MR returns
high. MR has an internal 20kΩ pullup resistor, so it can
be left unconnected if not used. Connect a normally
open momentary switch from MR to GND to create a
manual reset function; external debounce circuitry is
not required.
Ensuring a Valid Reset Output
down to V
= 0
CC
When V
falls below 1V and approaches the minimum
CC
operating voltage of 0.7V, push/pull-structured reset
sinking (or sourcing) capabilities decrease drastically.
High-impedance CMOS-logic inputs connected to the
RESET pin can drift to indeterminate voltages. This
does not present a problem in most cases, since most
Interfacing to µPs with
Bidirectional Reset Pins
V
CC
Since the RESET output on the MAX6805 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 1).
100kΩ
V
V
CC
CC
µP
MOTOROLA
68HCXX
MAX6805
RESET
MR
RESET
Negative-Going V
Transients
CC
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, these devices
are relatively immune to short-duration, negative-going
GND
GND
V
transients (glitches). The Typical Operating
CC
Characteristics show the Maximum Transient Duration
vs. Reset Comparator Overdrive graph. The graph
Figure 1. Interfacing to µPs with Bidirectional Reset Pins
4
_______________________________________________________________________________________
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
µPs and circuitry do not operate when V
drops below
Since the MAX6805 has an open-drain, active-low out-
put, it typically uses a pullup resistor. With this device,
RESET will most likely not maintain an active condition,
but will drift to a non-active level due to the pullup
resistor and the reduced sinking capability of the open-
drain device. Therefore, this device is not recommend-
ed for applications where the RESET pin is required to
CC
1V. For the MAX6804 application where RESET must be
valid down to 0, adding a pulldown resistor between
RESET and GND removes stray leakage currents, hold-
ing RESET low (Figure 2a). The pulldown resistor value
is not critical; 100kΩ is large enough not to load RESET,
and small enough to pull it low. For the MAX6803, where
RESET must be valid to V
= 0, a 100kΩ pullup resistor
be valid down to V
= 0.
CC
CC
between RESET and V
will hold RESET high when
CC
V
falls below 0.7V (Figure 2b).
CC
Pin Configuration
V
CC
TOP VIEW
MAX6804
V
CC
GND
1
4
MR
RESET
100kΩ
MAX6803
MAX6804
MAX6805
GND
(a)
V
CC
RESET (RESET)
2
3
MR
100kΩ*
SOT143
MAX6803
( ) ARE FOR MAX6803
MR
RESET
GND
(b)
Typical Operating Circuit
*ASSUMES HIGH-Z RESET INPUT TO THE µP
Figure 2. Ensuring Reset Valid down to V
= 0
V
CC
CC
V
CC
V
CC
µP
MAX6804
RESET
MR
RESET
GND
GND
PUSHBUTTON
SWITCH
_______________________________________________________________________________________
5
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
Table 1. Factory-Trimmed Reset Thresholds
RESET
THRESHOLD
SUFFIX
T
= +25°C
T = -40°C to +125°C
A
A
MIN
TYP (V
)
TH
MAX
4.886
4.785
4.713
4.581
4.459
4.377
4.276
4.174
4.072
3.970
3.868
3.767
3.665
3.563
3.461
3.359
3.258
3.135
3.054
2.983
2.850
2.749
2.677
MIN
MAX
4.944
4.841
4.769
4.635
4.511
4.429
4.326
4.223
4.120
4.017
3.914
3.811
3.708
3.605
3.502
3.399
3.296
3.172
3.090
3.018
2.884
2.781
2.709
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
4.714
4.615
4.547
4.419
4.301
4.223
4.124
4.026
3.928
4.830
3.732
3.633
3.535
3.437
3.339
3.241
3.142
3.025
2.946
2.877
2.750
2.651
2.583
4.80
4.70
4.63
4.50
4.38
4.30
4.20
4.10
4.00
3.90
3.80
3.70
3.60
3.50
3.40
3.30
3.20
3.08
3.00
2.93
2.80
2.70
2.63
4.656
4.559
4.491
4.365
4.249
4.171
4.074
3.977
3.880
3.783
3.686
3.589
3.492
3.395
3.298
3.201
3.104
2.988
2.910
2.842
2.716
2.619
2.551
6
_______________________________________________________________________________________
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
Selector Guide (Standard Versions*)
MIN RESET
TIMEOUT (ms)
SOT
TOP MARK
PART
OUTPUT STAGE
NOMINAL V (V)
TH
MAX6803US26D3-T
MAX6803US29D3-T
MAX6803US31D3-T
MAX6803US44D3-T
MAX6803US46D3-T
MAX6804US26D3-T
MAX6804US29D3-T
MAX6804US31D3-T
MAX6804US44D3-T
MAX6804US46D3-T
MAX6805US26D3-T
MAX6805US29D3-T
MAX6805US31D3-T
MAX6805US44D3-T
MAX6805US46D3-T
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
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
2.63
2.93
3.08
4.38
4.63
2.63
2.93
3.08
4.38
4.63
2.63
2.93
3.08
4.38
4.63
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
KACH
KACI
KACJ
KACK
KACL
KACN
KACP
KACQ
KACR
KACS
KACO
KACU
KACV
KACW
KACX
*Sample stock is generally held on all standard versions.
Chip Information
TRANSISTOR COUNT: 505
PROCESS: BiCMOS
_______________________________________________________________________________________
7
4-Pin, Low-Power
µP Reset Circuits with Manual Reset
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, SOT-143, 4L
1
21-0052
E
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
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