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19-1839; Rev 1; 04/01
SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits
General Description
The MAX6381-MAX6390 microprocessor (P) supervisory circuits monitor power supply voltages from +1.8V to +5.0V while consuming only 3A of supply current at +1.8V. Whenever VCC falls below the factory-set reset thresholds, the reset output asserts and remains asserted for a minimum reset timeout period after VCC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV increments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available. The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/ MAX6388 have a push-pull active-high reset output, and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer VCC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms). The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 packages and the MAX6384-MAX6390 are available in 4-pin SC70 packages.
Features
o Factory-Set Reset Threshold Voltages Ranging from +1.58V to +4.63V in Approximately 100mV Increments o 2.5% Reset Threshold Accuracy Over Temperature (-40C to +125C) o Seven Reset Timeout Periods Available: 1ms, 20ms, 140ms, 280ms, 560ms, 1120ms, 1200ms (min) o 3 Reset Output Options Active-Low Push-Pull Active-High Push-Pull Active-Low Open-Drain o Reset Output State Guaranteed Valid Down to VCC = 1V o Manual Reset Input (MAX6384/MAX6385/MAX6386) o Auxiliary RESET IN (MAX6387/MAX6388/MAX6389) o VCC Reset Timeout (1120ms or 1200ms)/Manual Reset Timeout (140ms or 150ms) (MAX6390) o Negative-Going VCC Transient Immunity o Low Power Consumption of 6A at +3.6V and 3A at +1.8V o Pin Compatible with MAX809/MAX810/MAX803/MAX6326/MAX6327/ MAX6328/MAX6346/MAX6347/MAX6348, and MAX6711/MAX6712/MAX6713 o Tiny 3-Pin SC70 and 4-Pin SC70 Packages
MAX6381-MAX6390
________________________Applications
Computers Controllers Intelligent Instruments Critical P and C Power Monitoring Portable/Battery-Powered Equipment Dual Voltage Systems
Ordering Information
PART MAX6381XR_ _D_-T TEMP. RANGE -40C to +125C -40C to +125C -40C to +125C PIN-PACKAGE 3 SC70-3 3 SC70-3 3 SC70-3
Pin Configurations
TOP VIEW
GND 1
MAX6382XR_ _D_-T MAX6383XR_ _D_-T
RESET (RESET) 2
MAX6381 MAX6382 MAX6383
3
VCC
Note: Insert reset threshold suffix (see Reset Threshold table) after "XR" or "XS". Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number. Sample stock is generally held on standard versions only (see Standard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces. Contact factory for availability of nonstandard versions. *MAX6390 is available with D4 or D7 timing only. Ordering Information continued at end of data sheet. Typical Operating Circuit appears at end of data sheet. Selector Guide appears at end of data sheet. 1
SC70 ( ) IS FOR MAX6382 Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..........................................................-0.3V to +6.0V RESET Open-Drain Output....................................-0.3V to +6.0V RESET, RESET (Push-Pull Output) .............-0.3V to (VCC + 0.3V) MR, RESET IN.............................................-0.3V to (VCC + 0.3V) Input Current (VCC) .............................................................20mA Output Current (All Pins) .....................................................20mA Continuous Power Dissipation (TA = +70C) 3-Pin SC70 (derate 2.9mW/C above +70C)........235mW 4-Pin SC70 (derate 3.1mW/C above +70C)........245mW Operating Temperature Range .........................-40C to +125C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
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 = -40C to +125C, unless otherwise specified. Typical values are at TA = +25C.) (Note 1)
PARAMETER Operating Voltage Range SYMBOL VCC VCC = 5.5V, no load VCC Supply Current ICC VCC = 3.6V, no load VCC = 2.5V, no load VCC = 1.8V, no load VCC Reset Threshold (See Reset Thresholds table) Reset Threshold Tempco VCC to Reset Delay TA = +25C VTH TA = -40C to +125C VTH/C VCC falling at 10mV/s from VTH + 100mV to VTH - 100mV D1 D2 Reset Timeout Period MAX6381-MAX6389 (See Reset Timeout table) D3 tRP D5 D6 D4 D7 MR timeout period Reset Timeout Period MAX6390 tRP VCC timeout period VIL VTH < 4V MR Input Voltage VIH VIL VIH VTH > 4V 0.7 VCC 0.8 2.4 D4 D7 D4 D7 1 20 140 280 560 1120 1200 140 150 1120 1200 VTH 1.5% VTH 2.5% CONDITIONS MIN 1.0 7 6 4 3 VTH VTH 60 35 2 40 280 560 1120 2240 2400 280 300 2240 2400 0.3 VCC V ms ms TYP MAX 5.5 13 11 7 6 VTH + 1.5% V VTH + 2.5% ppm/C s A UNITS V
2
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits
ELECTRICAL CHARACTERISTICS (continued)
(VCC = full range, TA = -40C to +125C, unless otherwise specified. Typical values are at TA = +25C.) (Note 1)
PARAMETER MR Minimum Input Pulse Width MR Glitch Rejection MR to Reset Delay MR Internal Pullup Resistance MAX6381-MAX6389 MAX6390 TA = +25C Reset IN Input Threshold VTHRST TA = 0C to +85C TA = -40C to +125C RESET IN to RESET Delay RESET IN Input Leakage Current Open-Drain RESET Output Voltage Open-Drain RESET Output Leakage Current IRESET IN VCC 4.5V, ISINK = 3.2mA, reset asserted VOL VCC 2.5V, ISINK = 1.2mA, reset asserted VCC 1.0V, ISINK = 80A, reset asserted ILKG VCC > VTH, RESET not asserted VCC 4.5V, ISINK = 3.2mA, reset asserted VOL Push-Pull RESET Output Voltage VOH VCC 2.5V, ISINK = 1.2mA, reset asserted VCC 1.0V, ISINK = 80A, reset asserted VCC 4.5V, ISOURCE = 800A, reset not asserted VCC 2.5V, ISOURCE = 500A, reset not asserted VCC 4.5V, ISOURCE = 800A, reset asserted VCC 2.5V, ISOURCE = 500A, reset asserted VOH VCC 1.8V, ISOURCE = 150A, reset asserted Push-Pull RESET Output Voltage VCC 1.0V, ISOURCE = 1A, reset asserted VCC 4.5V, ISINK = 3.2mA, reset not asserted VOL VCC 2.5V, ISINK = 1.2mA, reset not asserted 0.8 VCC 0.8 VCC 0.8 VCC 0.8 VCC 0.8 VCC 0.8 VCC 0.4 0.3 VRESETIN falling at 4mV/s from VTHRST + 40mV to VTHRST - 40mV -50 32 800 1.245 1.232 1.219 4.5 1 +50 0.4 0.3 0.3 1.0 0.4 0.3 0.3 V A V SYMBOL CONDITIONS MIN 1 100 200 63 1350 1.27 100 2300 1.295 1.308 1.321 s nA V TYP MAX UNITS s ns ns k
MAX6381-MAX6390
V
Note 1: Specifications over temperature are guaranteed by design, not production tested.
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
Typical Operating Characteristics
(TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE (NO LOAD)
MAX6381/90 toc01
POWER-DOWN RESET DELAY vs. TEMPERATURE
MAX6381/90 toc02
NORMALIZED POWER-UP RESET TIMEOUT vs. TEMPERATURE
NORMALIZED RESET TIMEOUT PERIOD
MAX6381/90 toc03
9 8 SUPPLY CURRENT (A) 7 6 5 4 3 2 1 0 VCC = +5.5V VCC = +3.6V
43 41 POWER-DOWN RESET DELAY (s) 39 37 35 33 31 29 27 25 VCC = +1.8V VCC = +3.0V
1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94
VCC = +2.5V
VCC = +1.8V
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
NORMALIZED RESET THRESHOLD vs. TEMPERATURE
MAX6381/90 toc04
OUTPUT VOLTAGE LOW vs. SINK CURRENT
MAX6381/90 toc05
OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT
VCC = +2.5V 2.5 2.0 VOH (V) 1.5 1.0 VCC = +1.8V
MAX6381/90 toc06
1.020 NORMALIZED RESET THRESHOLD 1.015 1.010 1.005 1.000 0.995 0.990 0.985
1.2 1.0 0.8 VOL (V) 0.6 VCC = +3.0V 0.4 0.2 0 0 3 6 ISINK (mA) 9 VCC = +4.5V
3.0
0.5 0 12 0 250 500 750 1000 1250 1500 ISOURCE (A)
0.990 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVE
MAX6381/90 toc07
RESET IN TO RESET DELAY vs. TEMPERATURE
5.3 5.1 RESET IN DELAY (s) 4.9 4.7 4.5 4.3 4.1 3.9 3.7 3.5
MAX6381/90 toc08
500 MAXIMUM TRANSIENT DURATION (s) 450 400 350 300 250 200 150 100 50 0 1 10 100 RESET ASSERTED ABOVE THIS LINE
5.5
1000
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
RESET COMPARATOR OVERDRIVE, VTH - VCC (mV)
4
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits
Pin Description
PIN MAX6384/ MAX6381/ MAX6387/ MAX6382 MAX6386/ MAX6385 MAX6388 MAX6389 MAX6383 MAX6390 1 1 1 1 1 1 NAME FUNCTION
MAX6381-MAX6390
GND
Ground Active-High Push-Pull Reset Output. RESET changes from low to high when any monitored voltage (VCC or VRESETIN) drops below the reset threshold or MR is pulled low. RESET remains high for the reset timeout period after monitored voltages exceed the reset thresholds or MR is released. Active-Low Open-Drain/Push-Pull Reset Output. RESET changes from high to low when any monitored voltage (VCC or VRESETIN) drops below the reset threshold or MR is pulled low. RESET remains low for the reset timeout period after the monitored voltages exceed the reset thresholds or MR is released. Open-drain requires an external pullup resistor. Active-Low Manual Reset Input. Drive low to force a reset. Reset remains active as long as MR is low and for the reset timeout period after MR is released. Leave unconnected or connect to VCC if unused. MR has an internal 63k (1.35k for MAX6390) pullup resistor to VCC. Auxiliary Reset Input. High-impedance input to the auxiliary reset comparator. Connect RESET IN to the center point of an external resistor voltage-divider network to set the reset threshold voltage. Reset asserts when either VCC or RESET IN falls below its threshold voltage. Supply Voltage for the device and input for fixed VCC reset threshold monitor.
--
2
--
2
--
2
RESET
2
--
2
--
2
--
RESET
--
--
3
3
--
--
MR
--
--
--
--
3
3
RESET IN
3
3
4
4
4
4
VCC
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
Detailed Description
RESET Output
A P reset input starts the P in a known state. These P supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions. Reset asserts when VCC is below the reset threshold; once VCC exceeds the reset threshold, an internal timer keeps the reset output asserted for the reset timeout period. After this interval, reset output deasserts. Reset output is guaranteed to be in the correct logic state for VCC 1V.
Reset Thresholds (-40C to +125C)
SUFFIX 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 VTH (min) 4.51 4.39 4.27 4.19 4.10 4.00 3.90 3.80 3.71 3.61 3.51 3.41 3.32 3.22 3.12 3.00 2.93 2.85 2.73 2.63 2.56 2.44 2.34 2.26 2.13 2.05 1.95 1.85 1.76 1.62 1.54 VTH (nom) 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 2.50 2.40 2.31 2.19 2.10 2.00 1.90 1.80 1.67 1.58 VTH (max) 4.74 4.61 4.48 4.41 4.31 4.20 4.10 4.00 3.90 3.79 3.69 3.59 3.49 3.38 3.28 3.15 3.08 3.00 2.87 2.77 2.69 2.56 2.46 2.37 2.24 2.15 2.05 1.95 1.85 1.71 1.61
Manual Reset Input (MAX6384/ MAX6385/MAX6386/MAX6390)
Many P-based products require manual reset capability, 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 (tRP) after MR returns high. This input has an internal 63k pullup resistor (1.35k for MAX6390), so it can be left unconnected if it is not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual-reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environment, connecting a 0.1F capacitor from MR to GND provides additional noise immunity.
RESET IN Comparator (MAX6387/MAX6388/MAX6389)
RESET IN is compared to an internal +1.27V reference. If the voltage at RESET IN is less than 1.27V, reset asserts. Use the RESET IN comparator as a useradjustable reset detector or as a secondary power-supply monitor by implementing a resistor-divider at RESET IN (shown in Figure 1). Reset asserts when either VCC or RESET IN falls below its respective threshold voltage. Use the following equation to set the threshold: VINTH = VTHRST (R1/R2 + 1) where VTHRST = +1.27V. To simplify the resistor selection, choose a value of R2 and calculate R1: R1 = R2 [(VINTH/VTHRST) - 1] Since the input current at RESET IN is 50nA (max), large values can be used for R2 with no significant loss in accuracy.
___________Applications Information
Negative-Going VCC Transients In addition to issuing a reset to the P during power-up, power-down, and brownout conditions, the MAX6381-MAX6390 are relatively immune to short duration negative-going VCC transients (glitches). The Typical Operating Characteristics section shows the Maximum Transient Durations vs. Reset Comparator Overdrive, for which the MAX6381-MAX6390 do not generate a reset pulse. This graph was generated using
6
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
VCC VIN R1 RESET IN R2 GND ( ) IS FOR MAX6388 MAX6387 MAX6388 MAX6389 RESET (RESET) GND MAX6381 MAX6384 MAX6387 RESET R1 100k VCC
Figure 1. RESET IN Configuration
Figure 2. RESET Valid to VCC = Ground Circuit
Reset Timeout Delay
SUFFIX D1 D2 D3 D5 D6 D4 D7 MAX6390XSD4 MAX6390XSD7 MIN 1ms 20ms 140ms 280ms 560ms 1120ms 1200ms 1120/140ms * 1200/150ms * PART
not work with the open-drain outputs of the MAX6383/MAX6386/MAX6389/MAX6390. The resistor value used is not critical, but it must be small enough not to load the reset output when VCC is above the reset threshold. For most applications, 100k is adequate.
Standard Versions
RESET THRESHOLD 46 44 31 29 MAX638_ 26 23 22 17 16 46 44 31 29 MAX6390 26 23 22 17 16 D4 D3 RESET TIMEOUT
* The MAX6390 has a 1120ms or 1200ms RESET timeout and a 140ms or 150ms manual reset timeout
a negative-going pulse applied to VCC, starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a negativegoing VCC transient may have without causing a reset pulse to be issued. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. A 0.1F capacitor mounted as close as possible to VCC provides additional transient immunity.
Ensuring a Valid RESET Output Down to VCC = 0
The MAX6381-MAX6390 are guaranteed to operate properly down to VCC = 1V. In applications that require valid reset levels down to VCC = 0, a pulldown resistor to active-low outputs (push/pull only, Figure 2) and a pullup resistor to active-high outputs (push/pull only) will ensure that the reset line is valid while the reset output can no longer sink or source current. This scheme does
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
Selector Guide
PART NUMBER MAX6381 MAX6382 MAX6383 MAX6384 MAX6385 MAX6386 MAX6390* MAX6387 MAX6388 MAX6389 X X X X X X X PUSH-PULL ACTIVE-LOW X X X X X X X X X X PUSH-PULL ACTIVE-HIGH OPEN-DRAIN ACTIVE-LOW MANUAL RESET INPUT MR RESET IN
*The MAX6390 offers a VCC reset timeout of 1120ms or 1200ms (min) and a manual reset timeout of 140ms or 150ms (min).
Typical Operating Circuit
I/O SUPPLY VCORE R1 RESET IN ** R1 MAX6381-MAX6390 MR * RESET (RESET) GND PUSHBUTTON SWITCH RESET INPUT GND VCC CORE I/O VOLTAGE VOLTAGE P
Pin Configurations (continued)
TOP VIEW
GND
1
4 VCC
MAX6384 MAX6385 MAX6386 MAX6390
RESET (RESET) 2 3 MR
( ) IS FOR MAX6385
SC70
* MR is for MAX6384/MAX6385/MAX6386/MAX6390 ** RESET IN is for MAX6387/MAX6388/MAX6389 ( ) are for MAX6382/MAX6385/MAX6388
GND
1
4
VCC
MAX6387 MAX6388 MAX6389
Chip Information
TRANSISTOR COUNT: 647 PROCESS: BiCMOS
RESET (RESET) 2 3 RESET IN
( ) IS FOR MAX6388
SC70
8
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits
Ordering Information (continued)
PART MAX6384XS_ _D_-T MAX6385XS_ _D_-T MAX6386XS_ _D_-T MAX6387XS_ _D_-T MAX6388XS_ _D_-T MAX6389XS_ _D_-T MAX6390XS_ _D_-T* TEMP. RANGE -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C PIN-PACKAGE 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4
MAX6381-MAX6390
Note: Insert reset threshold suffix (see Reset Threshold table) after "XR" or "XS". Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number. Sample stock is generally held on standard versions only (see Standard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces. Contact factory for availability of nonstandard versions. *MAX6390 is available with D4 or D7 timing only.
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
Package Information
SC70, 4L.EPS
10
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SC70, Single/Dual Low-Voltage, Low-Power P Reset Circuits MAX6381-MAX6390
Package Information (continued)
SC70, 3L.EPS
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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