General Description
The MAX6332/MAX6333/MAX6334 microprocessor (μP)
supervisory circuits monitor the power supplies in 1.8V to
3.3V μP and digital systems. They increase circuit reliability
and reduce cost by eliminating external components and
adjustments.
These devices perform a single function: they assert a
reset signal whenever the VCC supply voltage declines
below a preset threshold, keeping it asserted for a preset
timeout period after VCC has risen above the reset
threshold. The only difference among the three devices
is their output. The MAX6333 (push/pull) and MAX6334
(open-drain) have an active-low RESET output, while the
MAX6332 (push/pull) has an active-high RESET output.
The MAX6332/MAX6333 are guaranteed to be in the correct
state for VCC down to 0.7V. The MAX6334 is guaranteed
to be in the correct state for VCC down to 1.0V.
The reset comparator in these ICs is designed to ignore
fast transients on VCC. Reset thresholds are factory-trimmable
between 1.6V and 2.5V, in approximately 100mV increments.
There are 15 standard versions available (2,500 piece
minimum-order quantity); contact the factory for availability
of nonstandard versions (10,000 piece minimum-order
quantity). For space-critical applications, the MAX6332/
MAX6333/MAX6334 come packaged in a 3-pin SOT23.
Applications
● Pentium® II Computers
●Computers
●Controllers
● Intelligent Instruments
● Critical μP/μC Power Monitoring
● Portable/Battery-Powered Equipment
Benets and Features
● Ultra-Low 0.7V Operating Supply Voltage
● Low 3.3μA Supply Current
● Precision Monitoring of 1.8V and 2.5V Power- Supply
Voltages
● Reset Thresholds Available from 1.6V to 2.5V,
in Approximately 100mV Increments
● Fully Specified Over Temperature
● Three Power-On Reset Pulse Widths Available
(1ms min, 20ms min, 100ms min)
● Low Cost
● Three Available Output Structures: Push/Pull
RESET, Push/Pull RESET, Open-Drain RESET
● Guaranteed RESET/RESET Valid to VCC = 0.7V
(MAX6332/MAX6333)
● Power-Supply Transient Immunity
● No External Components
● 3-Pin SOT23 Package
● Pin-Compatible with MAX809/MAX810 and
MAX6326/MAX6327/MAX6328
Selector Guide (Standard Versions*) appears at end of data sheet.
Pentium is a registered trademark of Intel Corp.
19-1411; Rev 4; 2/16
MAX6332
MAX6333
VCC
VCC
RESET RESET
INPUT
GND
VCC
GND
µP
(RESET)
( ) ARE FOR MAX6332
Typical Operating Circuit
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
Terminal Voltage (with respect to GND)
VCC ...................................................................... -0.3V to +6V
Push/Pull RESET, RESET .................... -0.3V to (VCC + 0.3V)
Open-Drain RESET .............................................-0.3V to +6V
Input Current (VCC) ............................................................ 20mA
Output Current (RESET, RESET) ......................................20mA
Continuous Power Dissipation (TA = +70°C)
SOT23-3 (derate 4mW/°C above +70°C) .................... 320mW
Operating Temperature Range ......................... -40°C to +125°C
Storage Temperature Range ............................ -65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
Lead(Pb)-free packages .............................................. +260°C
Packages containing lead (Pb) .................................... +240°C
(VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C and VCC = 3V, reset not asserted.)
Absolute Maximum Ratings
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
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage Range VCC
TA = 0°C to +85°C MAX6332/MAX6333 0.7 5.5
V
MAX6334 1.0 5.5
TA = -40°C to +85°C MAX6332/MAX6333 0.78 5.5
MAX6334 1.2 5.5
TA = 0°C to +125°C MAX6332/MAX6333
MAX6334 1.2 5.5
Supply Current ICC No load VCC = 1.8V 3.0 6.0 µA
VCC = 2.5V 3.3 7.0
Reset Threshold VTH MAX633_UR__D_-T,
Table 1
TA = +25°C VTH
- 1.8% VTH
VTH
+ 1.8% V
TA = -40°C to +125°C VTH
- 3% VTH
VTH
+ 3%
VCC Falling Reset Delay VCC falling at 10V/ms 24 µs
Reset Active Timeout Period tRP
MAX633_UR__D1-T 11.5 2
msMAX633_UR__D2-T 20 30 40
MAX633_UR__D3-T 100 150 200
RESET Output Low Voltage
(MAX6333/MAX6334) VOL Reset
asserted
ISINK = 50µA, VCC ≥ 1.0V 0.4 V
ISINK = 500µA, VCC ≥ 1.8V 0.3
RESET Output High Voltage
(MAX6333) VOH Reset not
asserted
ISOURCE = 200µA, VCC ≥ 1.8V 0.8 x VCC V
ISOURCE = 500µA, VCC ≥ 2.7V 0.8 x VCC
RESET Output Voltage
(MAX6332)
VOH Reset
asserted
ISOURCE = 1µA, VCC ≥ 1.0V 0.8 x VCC
V
ISOURCE = 200µA, VCC ≥ 1.8V 0.8 x VCC
VOL Reset not
asserted
ISINK = 500µA, VCC ≥ 1.8V 0.3
ISINK = 1.2mA, VCC ≥ 2.7V 0.3
RESET Output Leakage
Current (MAX6334) VCC > VTH, RESET not asserted 0.5 µA
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
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(Reset not asserted, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics
2.0
2.6
2.2
3.0
3.6
3.8
3.4
3.2
4.0
-60
2.4
-40 -20 0
2.8
20 40 60 80 100
SUPPLY CURRENT vs. TEMPERATURE
MAX6332/33/34 toc01
TEMPERATURE (°C)
I
CC
(µA)
RESET NOT ASSERTED
VCC = 1.8V
VCC = 2.5V
100 1000
0
100
200
400
300
500
600
0.1 1 10
MAXIMUM TRANSIENT DURATION
vs. RESET COMPARATOR OVERDRIVE
MAX6332/33/34 toc04
RESET COMPARATOR OVERDRIVE (mV)
MAXIMUM TRANSIENT DURATION (µs)
RESET OCCURS
RESET DOES
NOT OCCUR
0.950
0.990
0.970
1.000
1.030
1.040
1.020
1.010
1.050
-60 -40
0.980
-20 0
0.960
20 40 60 80 100
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
MAX6332/33/34 toc02
TEMPERATURE (°C)
NORMALIZED RESET TIMEOUT PERIOD
VTH = 2.2V
0
40
20
80
60
100
120
140
160
0.5 1.0 1.250.75 1.5 1.75 2.0 2.25 2.5
OUTPUT VOLTAGE HIGH
vs. SUPPLY VOLTAGE
MAX6332/33/34 toc05
VCC (V)
OUTPUT VOLTAGE HIGH (V
CC
- V
OH
) (mV)
VTH = 2.2V
ISOURCE = 100µA
RESET ASSERTED
TA = -40°C
TA = +85°C
TA = +25°C
0
20
10
30
60
70
50
40
80
0.5 1.00 1.50 2.00 2.50 3.00
OUTPUT VOLTAGE LOW
vs. SUPPLY VOLTAGE
MAX6332/33/34 toc06
VCC (V)
OUTPUT VOLTAGE LOW (mV)
VTH = 2.5V
ISINK = 500µA
RESET ASSERTED
TA = -40°C
TA = +85°C
TA = +25°C
10
40
50
70
60
80
-60 -40
30
-20 0
20
20 40 60 80 100
VCC FALLING PROPAGATION DELAY
vs. TEMPERATURE
MAX6332/33/34 toc03
TEMPERATURE (°C)
VCC FALLING AT 10V/ms
VCC FALLING AT 1V/ms
PROPAGATION DELAY (µs)
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
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TOP VIEW
1
2
3VCC
RESET (RESET)
MAX6332
MAX6333
MAX6334
SOT23-3
( ) ARE FOR MAX6332
GND
Pin Conguration
Pin Description
PIN
NAME FUNCTION
MAX6332 MAX6333
MAX6334
1 1 GND Ground
— 2 RESET
Active-Low Reset Output. RESET remains low while VCC is below the reset
threshold and for a reset timeout period (tRP) after VCC rises above the
reset threshold. RESET on the MAX6334 is open-drain.
2 — RESET
Active-High Reset Output. RESET remains high while VCC is below the
reset threshold and for a reset timeout period (tRP) after VCC rises above
the reset threshold.
3 3 VCC Supply Voltage (0.7V to 5.5V)
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
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Applications Information
Interfacing to μPs with Bidirectional
Reset Pins
Since the RESET output on the MAX6334 is open-
drain, this device interfaces easily with 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 pullup
resistor allows either device to assert reset (Figure 1).
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). The Typical Operating
Characteristics show the Maximum Transient Duration vs.
Reset Comparator Overdrive graph. The graph shows the
maximum pulse width that a negative-going VCC transient
may typically have without issuing a reset signal. As the
amplitude of the transient increases, the maximum allowable
pulse width decreases.
Ensuring a Valid Reset Output Down to
VCC = 0
When VCC falls below 1V and approaches the minimum
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 μPs
and circuitry do not operate at VCC below 1V. For the
MAX6333, where RESET must be valid down to 0, adding
a pull-down resistor between RESET and GND removes
stray leakage currents, holding RESET low (Figure 2a).
The pull-down resistor value is not critical; 100kΩ is large
enough not to load RESET and small enough to pull it low.
For the MAX6332, where RESET must be valid to VCC =
0, a 100kΩ pull-up resistor between RESET and VCC will
hold RESET high when VCC falls below 0.7V (Figure 2b).
Since the MAX6334 has an open-drain, active-low
output, it typically uses a pull-up resistor. With this device,
RESET will most likely not maintain an active condition,
but will drift to a non-active level due to the pull-up resistor and
the reduced sinking capability of the open-drain device.
Therefore, this device is not recommended for applications
where the RESET pin is required to be valid down to VCC = 0.
Figure 1. Interfacing to μPs with Bidirectional Reset Pins
*Factory-trimmed reset thresholds are available in approximately
100mV increments, with a ±1.8% room-temperature variance.
Figure 2. Ensuring Reset Valid Down to VCC = 0
Table 1. Factory-Trimmed Reset
Thresholds*
VCC
VCC
GND
MAX6334
RESET
VCC
GND
RESET
INPUT
MOTOROLA
68HCXX
µP
VCC
GND
MAX6333
RESET
100kΩ
(a)
VCC
GND
MAX6332
RESET
100kΩ*
(b)
*ASSUMES HIGH-Z RESET INPUT TO THE µP
RESET-
THRESHOLD
SUFFIX
TA = +25°C TA = -40°C to
+125°C BIT 4
MIN TYP MAX MIN MAX
MAX633_UR25D_ 2.46 2.50 2.55 2.43 2.58
MAX633_UR24D_ 2.36 2.40 2.44 2.33 2.47
MAX633_UR23D_ 2.26 2.30 2.34 2.23 2.37
MAX633_UR22D_ 2.16 2.20 2.24 2.13 2.27
MAX633_UR21D_ 2.06 2.10 2.14 2.04 2.16
MAX633_UR20D_ 1.96 2.00 2.04 1.94 2.06
MAX633_UR19D_ 1.87 1.90 1.93 1.84 1.96
MAX633_UR18D_ 1.77 1.80 1.83 1.75 1.85
MAX633_UR17D_ 1.67 1.70 1.73 1.65 1.75
MAX633_UR16D_ 1.57 1.60 1.63 1.55 1.65
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
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*Sample stock is generally held on all standard versions.
*These devices are available in factory-set VCC reset thresholds
from 1.6V to 2.5V, in approximately 0.1V increments. Choose
the desired reset threshold suffix from Table 1 and insert it in the
blanks following “UR” 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 standard 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 nonstandard
versions (required order increment is 10,000 pieces). 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.
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX6332UR__D_-T -40°C to +125°C 3 SOT23
MAX6333UR__D_-T -40°C to +125°C 3 SOT23
MAX6334UR__D_-T -40°C to +125°C 3 SOT23
Selector Guide (Standard Versions*)
PART OUTPUT STAGE NOMINAL VTH (V) MINIMUM RESET
TIMEOUT (ms) SOT TOP MARK
MAX6332UR23D3-T Push/Pull RESET 2.30 100 FZDM
MAX6332UR22D3-T Push/Pull RESET 2.20 100 FZCN
MAX6332UR20D3-T Push/Pull RESET 2.00 100 FZDL
MAX6332UR18D3-T Push/Pull RESET 1.80 100 FZCM
MAX6332UR16D3-T Push/Pull RESET 1.60 100 FZCL
MAX6333UR23D3-T Push/Pull RESET 2.30 100 FZCS
MAX6333UR22D3-T Push/Pull RESET 2.20 100 FZCR
MAX6333UR20D3-T Push/Pull RESET 2.00 100 FZCQ
MAX6333UR18D3-T Push/Pull RESET 1.80 100 FZCP
MAX6333UR16D3-T Push/Pull RESET 1.60 100 FZCO
MAX6334UR23D3-T Open-Drain RESET 2.30 100 FZDO
MAX6334UR22D3-T Open-Drain RESET 2.20 100 FZCV
MAX6334UR20D3-T Open-Drain RESET 2.00 100 FZDN
MAX6334UR18D3-T Open-Drain RESET 1.80 100 FZCU
MAX6334UR16D3-T Open-Drain RESET 1.60 100 FZCT
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
3 SOT23 U3+1 21-0051 90-0179
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.
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
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Maxim Integrated
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Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 12/98 Initial release —
16/00 Revised Ordering Information, Absolute Maximum Ratings, Electrical
Characteristics, and Table 1. 1, 2, 4
212/05 Revised Ordering Information to add lead-free information. 1
3 6/12 Update Ordering Information with automotive part. 1
4 2/16 Updated Ordering Information table and Applications section 1
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 specications 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.
MAX6332/MAX6333/
MAX6334
3-Pin, Ultra-Low-Voltage, Low-Power
μP Reset Circuits
© 2016 Maxim Integrated Products, Inc.
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MAX6333UR21D1+T MAX6332UR16D1+T MAX6332UR16D2+T MAX6332UR16D3+T MAX6332UR17D1+T
MAX6332UR17D2+T MAX6332UR17D3+T MAX6332UR18D1+T MAX6332UR18D2+T MAX6332UR18D3+T
MAX6332UR19D1+T MAX6332UR19D2+T MAX6332UR20D1+T MAX6332UR20D2+T MAX6332UR20D3+T
MAX6332UR21D1+T MAX6332UR21D2+T MAX6332UR21D3+T MAX6332UR22D1+T MAX6332UR22D2+T
MAX6332UR22D3+T MAX6332UR23D1+T MAX6332UR23D2+T MAX6332UR23D3+T MAX6332UR24D1+T
MAX6332UR24D2+T MAX6332UR24D3+T MAX6332UR25D1+T MAX6332UR25D2+T MAX6332UR25D3+T
MAX6333UR16D1+T MAX6333UR16D2+T MAX6333UR16D3+T MAX6333UR17D1+T MAX6333UR17D2+T
MAX6333UR17D3+T MAX6333UR18D1+T MAX6333UR18D2+T MAX6333UR18D3+T MAX6333UR19D1+T
MAX6333UR19D2+T MAX6333UR19D3+T MAX6333UR20D1+T MAX6333UR20D2+T MAX6333UR20D3+T
MAX6333UR21D2+T MAX6333UR21D3+T MAX6333UR22D1+T MAX6333UR22D2+T MAX6333UR22D3+T
MAX6333UR23D1+T MAX6333UR23D2+T MAX6333UR23D3+T MAX6333UR24D1+T MAX6333UR24D2+T
MAX6333UR24D3+T MAX6333UR25D1+T MAX6333UR25D2+T MAX6333UR25D3+T MAX6334UR16D1+T
MAX6334UR16D2+T MAX6334UR16D3+T MAX6334UR17D1+T MAX6334UR17D2+T MAX6334UR17D3+T
MAX6334UR18D1+T MAX6334UR18D2+T MAX6334UR18D3+T MAX6334UR19D1+T MAX6334UR19D2+T
MAX6334UR19D3+T MAX6334UR20D1+T MAX6334UR20D2+T MAX6334UR20D3+T MAX6334UR21D1+T
MAX6334UR21D2+T MAX6334UR21D3+T MAX6334UR22D1+T MAX6334UR22D2+T MAX6334UR22D3+T
MAX6334UR23D1+T MAX6334UR23D2+T MAX6334UR23D3+T MAX6334UR24D1+T MAX6334UR24D2+T
MAX6334UR24D3+T MAX6334UR25D1+T MAX6334UR25D2+T MAX6334UR25D3+T