MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
General Description
The MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/
MAX6348 microprocessor (µP) supervisory circuits monitor the power supplies in µP and digital systems. These
devices provide excellent circuit reliability and low cost by
eliminating external components and adjustments when
used with 2.5V, 3V, 3.3V, and 5V powered circuits.
These circuits perform a single function: they assert a
reset signal whenever the VCC supply voltage declines
below a preset threshold, keeping it asserted for at least
100ms after VCC has risen above the reset threshold.
The only difference between the devices is their output. The MAX6326/MAX6346 (push-pull) and MAX6328/
MAX6348 (open-drain) have an active-low reset output.
The MAX6327/MAX6347 have an active-high push-pull
reset output. All of these parts are guaranteed to be in the
correct state for VCC down to 1V. The reset comparator is
designed to ignore fast transients on VCC. Reset thresholds are factory-trimmable between 2.2V and 4.63V, in
approximately 100mV increments. Twenty-one standard
versions are available. Contact the factory for availability
of nonstandard versions.
Ultra-low supply currents (1µA max for the MAX6326/
MAX6327/MAX6328) make these parts ideal for use in
portable equipment. All six devices are available in spacesaving SOT23 and SC70 packages.
Applications
●● Computers
●● Intelligent Instruments
●● Controllers
●● Critical µP and µC
Power Monitoring
●● Portable/Battery-Powered
Equipment
Pin Configuration
TOP VIEW
GND
1
MAX6326
MAX6327
MAX6328
MAX6346
MAX6347
MAX6348
(RESET) RESET
2
SOT23-3/SC70-3
( ) ARE FOR THE MAX6327/MAX6347.
19-1294; Rev 5; 4/14
3
VCC
Features
●● Ultra-Low 1µA (max) Supply Current
(MAX6326/MAX6327/MAX6328)
●● Precision Monitoring of 2.5V, 3V, 3.3V, and 5V
Power-Supply Voltages
●● Reset Thresholds Available from 2.2V to 4.63V
●● Fully Specified Over Temperature
●● 100ms (min) Power-On Reset Pulse Width
●● Low Cost
●● Available in Three Versions: Push-Pull RESET,
Push-Pull RESET, and Open-Drain RESET
●● Power-Supply Transient Immunity
●● No External Components
●● 3-Pin SC70/SOT23 Packages
●● Pin Compatible with MAX803/MAX809/MAX810
Ordering Information
PART†
TEMP. RANGE
PIN-PACKAGE
MAX6326XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6326UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6327XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6327UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6328XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6328UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6346XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6346UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6347XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6347UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6348XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6348UR_ _-T
-40°C to +85°C
3 SOT23-3
†The MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/
MAX6348 are available in factory-set VCC reset thresholds
from 2.2V to 4.63V, in approximately 0.1V increments. Choose
the desired reset-threshold suffix from Table 1 and insert it in
the blank spaces following “R”. There are 21 standard versions with a required order increment of 2500 pieces. Sample
stock is generally held on the standard versions only (see the
Selector Guide). Required order increment is 10,000 pieces for
nonstandard versions (Table 2). Contact factory for availability.
All devices available in tape-and-reel only.
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.
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Absolute Maximum Ratings
Terminal Voltage (with respect to GND)
VCC..........................................................................-0.3V to +6V
RESET, RESET (push-pull).......................-0.3V to (VCC + 0.3V)
RESET (open drain).................................................-0.3V to +6V
Input Current (VCC)............................................................20mA
Output Current (RESET, RESET).......................................20mA
Rate of Rise (VCC).........................................................100V/µs
Continuous Power Dissipation (TA = +70°C)
3-Pin SC70 (derate 2.7mW/°C above +70°C)..............174mW
3-Pin SOT23 (derate 4mW/°C above +70°C)..............320mW
Operating Temperature Range............................ -40°C to +85°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
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, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C and VCC = 3V.) (Note 1)
PARAMETER
SYMBOL
VCC Range
Supply Current
Reset Threshold
Reset Threshold Tempco
ICC
VTH
CONDITIONS
5.5
TA = -40°C to +85°C
1.2
5.5
MAX632_ only, VCC = 3.0V for VTH ≤ 2.93V,
VCC = 3.2V for VTH > 2.93V, no load
0.5
VCC = 5.5V, no load
Table 1
1.0
1.75
TA = +25°C
VTH
VTH +
1.5%
TA = -40°C to +85°C
VTH 2.5%
VTH
VTH +
2.5%
100
RESET Output Voltage
(MAX6326/MAX6346)
VOH
VOH
VOL
185
280
0.4
0.8 · VCC
ISOURCE = 800µA, VCC = VTH(MAX), VTH ≥ 4.5V
0.8 · VCC
ISOURCE = 500µA, VCC ≥ 2.1V, reset asserted
0.8 · VCC
ISOURCE = 50µA, VCC ≥ 1.2V, reset asserted
0.8 · VCC
ms
V
V
ISINK = 1.2mA, VCC ≥ 3.2V, reset not asserted,
MAX6327 only
0.3
ISINK = 3.2mA, VCC ≥ 4.5V, reset not asserted,
VTH ≤ 4.38V
0.4
V
0.4
MAX6326/MAX6327/MAX6328
6.3
MAX6346/MAX6347/MAX6348
9.5
Open-Drain RESET
Output Leakage Current
V
µs
ISINK = 100µA, VCC ≥ 1.2V, reset asserted
0.8 · VCC
µA
ppm/°C
0.3
ISOURCE = 800µA, VCC = 4.5V, VTH ≤ 4.38V
V
20
ISINK = 1.6mA, VCC > 2.1V, reset asserted
ISOURCE = 500µA, VCC = 3.2V, MAX6326 only
UNITS
40
ISINK = 3.2mA, VCC = VTH(MAX), VTH ≥ 4.5V
RESET Threshold
Hysteresis
1.0
VTH 1.5%
Reset Active Timeout Period
VOL
MAX
1.0
VCC = VTH to (VTH - 100mV)
RESET Output Voltage
(MAX6326/MAX6328/
MAX6346/MAX6348)
TYP
TA = 0°C to +70°C
∆VTH/°C
VCC to Reset Delay
RESET Output Voltage
(MAX6327/MAX6347)
MIN
mV
0.1
µA
Note 1: Overtemperature limits are guaranteed by design and not production tested.
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Maxim Integrated │ 2
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
0.8
200
RESET DELAY (µs)
VCC = 5V
0.7
0.6
VCC = 3.3V
0.5
0.4
0.3
0.2
150
100
-20
0
20
40
60
0
80
190
180
170
160
150
140
0
20
40
60
80
TEMPERATURE (°C)
500
MAXIMUM TRANSIENT DURATION (µs)
MAX6326 toc03
200
-20
-20
0
20
40
60
80
TEMPERATURE (°C)
POWER-UP RESET TIMEOUT
vs. TEMPERATURE
-40
VOD = 200mV
-40
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE (SC70)
MAX6326 toc04
-40
210
POWER-UP RESET TIMEOUT (ms)
VOD = 10mV
VOD = 100mV
VCC = 1.2V
TEMPERATURE (°C)
130
VOD = 20mV
50
0.1
0
MAX6326 toc02
0.9
SUPPLY CURRENT (µA)
POWER-DOWN RESET DELAY
vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
MAX6326 toc01
1.0
400
300
200
100
0
1
10
100
1000
RESET THRESHOLD OVERDRIVE,
VTH - VCC (mV)
Pin Description
PIN
MAX6326/MAX6346
MAX6328/MAX6348
MAX6327
MAX6347
NAME
FUNCTION
1
1
GND
Ground
2
—
RESET
Active-Low Reset Output. RESET remains low while VCC is below the reset
threshold and for at least 100ms after VCC rises above the reset threshold.
RESET is open-drain on the MAX6328/MAX6348 and push-pull on the
MAX6326/MAX6346.
—
2
RESET
Active-High Reset Output. RESET remains high while VCC is below the reset
threshold and for at least 100ms after VCC rises above the reset threshold.
3
3
VCC
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Supply Voltage
Maxim Integrated │ 3
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Applications Information
VCC
Interfacing to µPs with
Bidirectional Reset Pins
Since the RESET output on the MAX6328/MAX6348 is
open drain, these devices interface easily with microprocessors (µPs) that have bidirectional 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 pull-up resistor allows either
device to assert reset (Figure 1).
µP
MAX6328
MAX6348
MOTOROLA
68HCXX
RESET
INPUT
RESET
Negative-Going VCC Transients
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 VCC
transients (glitches).
VCC
VCC
GND
GND
Figure 1. Interfacing to μPs with Bidirectional Reset Pins
The Typical Operating Characteristics show the Maximum Transient Duration vs. Reset Threshold Overdrive
graph, for which reset pulses are not generated. The
graph shows the maximum pulse width that a negativegoing VCC transient may typically have when issuing a
reset signal. As the amplitude of the transient increases,
the maximum allowable pulse width decreases.
Table 1. Factory-Trimmed Reset Thresholds‡
PART
SUFFIX
MIN
RESET THRESHOLD VOLTAGE, VTH (V)
TA = +25°C
TA = -40°C to +85°C
TYP
MAX
MIN
MAX
MAX632_ _R
22
2.167
2.200
2.233
2.145
2.250
MAX632_ _R
23
2.285
2.320
2.355
2.262
2.375
MAX632_ _R
24
2.364
2.400
2.436
2.340
2.460
MAX632_ _R
25
2.462
2.500
2.537
2.437
2.562
MAX632_ _R
26
2.591
2.630
2.669
2.564
2.696
MAX632_ _R
27
2.660
2.700
2.741
2.633
2.768
MAX632_ _R
28
2.758
2.800
2.842
2.730
2.870
MAX632_ _R
29
2.886
2.930
2.974
2.857
3.000
MAX632_ _R
30
2.955
3.000
3.045
2.925
3.075
MAX632_ _R
31
3.034
3.080
3.126
3.003
3.150
MAX634_ _R
33
3.250
3.300
3.350
3.217
3.383
MAX634_ _R
34
3.349
3.400
3.451
3.315
3.485
MAX634_ _R
35
3.447
3.500
3.552
3.412
3.587
MAX634_ _R
36
3.546
3.600
3.654
3.510
3.690
MAX634_ _R
37
3.644
3.700
3.755
3.607
3.792
MAX634_ _R
38
3.743
3.800
3.857
3.705
3.895
‡Factory-trimmed reset thresholds are available in approximately 100mV increments with a 1.5% room-temperature variance.
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Maxim Integrated │ 4
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Table 1. Factory-Trimmed Reset Thresholds‡ (continued)
PART
RESET THRESHOLD VOLTAGE, VTH (V)
SUFFIX
MIN
TA = +25°C
TA = -40°C to +85°C
TYP
MAX
MIN
MAX
MAX634_ _R
39
3.841
3.900
3.958
3.802
3.997
MAX634_ _R
40
3.940
4.000
4.060
3.900
4.100
MAX634_ _R
41
4.038
4.100
4.161
3.997
4.202
MAX634_ _R
42
4.137
4.200
4.263
4.095
4.305
MAX634_ _R
43
4.235
4.300
4.364
4.192
4.407
MAX634_ _R
44
4.314
4.380
4.446
4.270
4.489
MAX634_ _R
45
4.432
4.500
4.567
4.387
4.612
MAX634_ _R
46
4.560
4.630
4.699
4.514
4.746
‡Factory-trimmed reset thresholds are available in approximately 100mV increments with a 1.5% room-temperature variance.
Table 2. Device Marking Codes and Minimum Order Increments
PART
MAX6346_R46-T
TOP MARK
SOT23
SC70
ORDER
INCREMENT(k)
FZBI
ACO
2.5
PART
MAX6347_R46-T
TOP MARK
ORDER
SOT23
SC70
INCREMENT (k)
FZBW
ACF
2.5
MAX6346_R45-T
FZBH
–
10
MAX6347_R45-T
FZBV
–
10
MAX6346_R44-T
FZBG
ACK
2.5
MAX6347_R44-T
FZBU
ACL
2.5
MAX6346_R43-T
FZBF
–
10
MAX6347_R43-T
FZBT
–
10
MAX6346_R42-T
FZBE
–
10
MAX6347_R42-T
FZBS
–
10
MAX6346_R41-T
FZBD
–
10
MAX6347_R41-T
FZBR
–
10
MAX6346_R40-T
FZBC
–
10
MAX6347_R40-T
FZBQ
–
10
MAX6346_R39-T
FZBB
–
10
MAX6347_R39-T
FZBP
–
10
MAX6346_R38-T
FZBA
–
10
MAX6347_R38-T
FZBO
–
10
MAX6346_R37-T
FZAZ
–
10
MAX6347_R37-T
FZBN
–
10
MAX6346_R36-T
FZAY
–
10
MAX6347_R36-T
FZBM
–
10
MAX6346_R35-T
FZAX
–
10
MAX6347_R35-T
FZBL
–
10
MAX6346_R34-T
FZAW
–
10
MAX6347_R34-T
FZBK
–
10
MAX6346_R33-T
FZAV
–
10
MAX6347_R33-T
FZBJ
–
10
MAX6326_R31-T
FDAA
ACE
2.5
MAX6327_R31-T
FMAA
ACT
2.5
MAX6326_R30-T
FEAA
–
10
MAX6327_R30-T
FNAA
–
10
MAX6326_R29-T
FCAA
ACP
2.5
MAX6327_R29-T
FLAA
ACS
2.5
MAX6326_R28-T
FBAA
–
10
MAX6327_R28-T
FKAA
–
10
MAX6326_R27-T
FAAA
–
10
MAX6327_R27-T
FJAA
–
10
MAX6326_R26-T
EZAA
ACI
2.5
MAX6327_R26-T
FIAA
ACR
2.5
MAX6326_R25-T
EYAA
–
10
MAX6327_R25-T
FHAA
–
10
MAX6326_R24-T
EXAA
–
10
MAX6327_R24-T
FGAA
–
10
MAX6326_R23-T
EWAA
ACH
2.5
MAX6327_R23-T
FFAA
ACQ
2.5
MAX6326_R22-T
EHAA
AAH
2.5
MAX6327_R22-T
EIAA
AAI
2.5
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Maxim Integrated │ 5
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Table 2. Device Marking Codes and Minimum Order Increments (continued)
TOP MARK
PART
MAX6348_R46-T
MAX6348_R46-T
MAX6348_R45-T
MAX6348_R44-T
MAX6348_R43-T
MAX6348_R42-T
MAX6348_R41-T
MAX6348_R40-T
MAX6348_R39-T
MAX6348_R38-T
MAX6348_R37-T
MAX6348_R36-T
MAX6348_R35-T
SOT23
SC70
SOT23
FZCK
FZCJ
FZCI
FZCH
FZCG
FZCF
FZCE
FZCD
FZCC
FZCB
FZCA
FZBZ
SC70
ACN
–
ACM
–
–
–
–
–
–
–
–
–
ORDER
INCREMENT (k)
2.5
10
2.5
10
10
10
10
10
10
10
10
10
Selector Guide (standard versions*)
PART
NOMINAL VTH (V)
MAX634_ _R46-T
4.63
MAX634_ _R44-T
4.38
MAX632_ _R31-T
3.08
MAX632_ _R29-T
2.93
MAX632_ _R26-T
2.63
MAX632_ _R23-T
2.32
MAX632_ _R22-T
2.20
*Sample stock is generally held on all standard versions.
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TOP MARK
PART
ORDER
INCREMENT (k)
SOT23
SC70
MAX6348_R34-T
FZBY
–
10
MAX6348_R33-T
FZBX
–
10
MAX6328_R31-T
FVAA
ACW
2.5
MAX6328_R30-T
FWAA
–
10
MAX6328_R29-T
FUAA
ACV
2.5
MAX6328_R28-T
FTAA
–
10
MAX6328_R27-T
FSAA
–
10
MAX6328_R26-T
FRAA
ACJ
2.5
MAX6328_R25-T
FQAA
–
10
MAX6328_R24-T
FPAA
–
10
MAX6328_R23-T
FOAA
ACU
2.5
MAX6328_R22-T
EJAA
AAJ
2.5
Chip Information
TRANSISTOR COUNT: 419
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.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
OUTLINE
NO.
LAND
PATTERN NO.
3 SC70
X3-2
21-0075
90-0208
3 SOT23
U3-1
21-0051
90-0179
Maxim Integrated │ 6
MAX6326/MAX6327/
MAX6328/MAX6346/
MAX6347/MAX6348
3-Pin, Ultra-Low-Power SC70/SOT
μP Reset Circuits
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
12/05
Initial release
—
1
4/14
No /V OPNs; removed Automotive reference from Applications section
1
DESCRIPTION
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 7