MAX6386XS25D6+中文资料

19-1839; Rev 4; 4/07

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

General Description

Features

The MAX6381–MAX6390 microprocessor (µP) supervisorycircuits monitor power-supply voltages from +1.8V to Factory-Set Reset Threshold Voltages Rangingfrom +1.58V to +4.63V in Approximately 100mV+5.0V while consuming only 3µA of supply current atIncrements

+1.8V. Whenever VCCfalls below the factory-set resetthresholds, the reset output asserts and remains assert- ±2.5% Reset Threshold Accuracy Overed for a minimum reset timeout period after VTemperature (-40°C to +125°C)above the reset threshold. Reset thresholds are availableCCrises Seven Reset Timeout Periods Available: 1ms,from +1.58V to +4.63V, in approximately 100mV incre-20ms, 140ms, 280ms, 560ms, 1120ms, ments. Seven minimum reset timeout delays ranging1200ms (min)from 1ms to 1200ms are available.

3 Reset Output Options

The MAX6381/MAX6384/MAX6387 have a push-pullActive-Low Push-Pullactive-low reset output. The MAX6382/MAX6385/Active-High Push-PullMAX6388 have a push-pull active-high reset output,Active-Low Open-Drain

and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The Reset Output State Guaranteed Valid Down to VMAX6384/MAX6385/MAX6386 also feature aCC= 1V

debounced manual reset input (with internal pullup Manual Reset Input (MAX6384/MAX6385/MAX6386)resistor). The MAX6387/MAX6388/MAX6389 have an Auxiliary RESETauxiliary input for monitoring a second voltage. The(MAX6387/MAX6388/MAX6389)

IN

MAX6390 offers a manual reset input with a longer Vreset timeout period (1120ms or 1200ms) and a shorterCC VCCReset Timeout (1120ms or 1200ms)/ManualReset Timeout (140ms or 150ms) (MAX6390)manual reset timeout (140ms or 150ms).

The MAX6381/MAX6382/MAX6383 are available in Negative-Going VCCTransient Immunity3-pin SC70 and6-pinµDFNpackages and the Low Power Consumption of 6µA at +3.6V MAX6384–MAX6390 are available in 4-pin SC70 and

and 3µA at +1.8V Pin Compatible with

MAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348, ComputersCritical µP and µCand MAX6711/MAX6712/MAX6713

Controllers

Power Monitoring Tiny 3-Pin/4-Pin SC70 and 6-Pin µDFNPackages

Intelligent Instruments

Portable/Battery-Powered EquipmentOrdering Information

Dual Voltage Systems

Pin Configurations

after "XR", "XS", or "LT." Insert reset timeout delay (see ResetTimeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.+Denotes a lead-free package.

Ordering Information continuedat end of data sheet.

Typical Operating Circuit appears at end of data sheet.Selector Guide appears at end of data sheet.

________________________________________________________________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 http://.

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits

MAX6381–MAX6390

ABSOLUTE MAXIMUM RATINGS

VCC to GND..........................................................-0.3V to +6.0VRESETOpen-Drain Output....................................-0.3V to +6.0VRESET, RESET (push-pull output)..............-0.3V to (VCC+ 0.3V)MR, RESET IN.............................................-0.3V to (VCC+ 0.3V)Input Current (VCC).............................................................20mAOutput Current (all pins).....................................................20mA

Continuous Power Dissipation (TA= +70°C)

3-Pin SC70 (derate 2.9mW/°C above +70°C)..............235mW4-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW6-Pin µDFN (derate 2.1mW/°C above +70°C)..........167.7mWOperating Temperature Range.........................-40°C to +125°CStorage Temperature Range.............................-65°C to +150°CLead 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 functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(VCC= full range, TA= -40°C to +125°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

_______________________________________________________________________________________3

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381–MAX6390

(TA = +25°C, unless otherwise noted.)

SUPPLY CURRENT vs. TEMPERATURE

(NO LOAD)

POWER-DOWN RESET DELAY

vs. TEMPERATURE

NORMALIZED RESET TIMEOUT PERIOD

41POWER-DOWN RESET DELAY (µs)

3937353331292725

NORMALIZED POWER-UP RESET TIMEOUT

vs. TEMPERATURE

MAX6381/90 toc03

98SUPPLY CURRENT (µA)

76543210

43

1.081.061.041.021.000.980.960.94

-40-25-105203550658095110125

TEMPERATURE (°C)

-40-25-10520355065

8095110125

TEMPERATURE (°C)

-40-25-105203550658095110125

TEMPERATURE (°C)

NORMALIZED RESET THRESHOLD

vs. TEMPERATURE

MAX6381/90 toc04

OUTPUT-VOLTAGE LOWvs. SINK CURRENT

OUTPUT-VOLTAGE HIGHvs. SOURCE CURRENT

1.020NORMALIZED RESET TH

RESHOLD1.0151.0101.0051.0000.9950.9900.985

1.21.00.8

3.02.52.0VOH (V)

1.51.0

VOL (V)

0.6

0.40.200

3

6ISINK (mA)

9

12

0.500

250

500

750

1000

1250

1500

ISOURCE (µA)

0.990

-40-25-105203550658095110125

TEMPERATURE (°C)

MAXIMUM TRANSIENT DURATIONvs. RESET COMPARATOR OVERDRIVE

RESET IN TO RESET DELAY

vs. TEMPERATURE

5.35.1RESET IN DELAY (µs)

4.94.74.54.34.13.93.73.5

MAX6381/90 toc08

500

MAXIMUM TRANSIENT DURATION (µs)

450400350300250200150100500

1

10

100

5.5

1000-40-25-105203550658095110125

TEMPERATURE (°C)

RESET COMPARATOR OVERDRIVE, VTH - VCC (mV)

4______________________________________________________________________________________

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

Pin Description

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381–MAX6390

Detailed Description

RESET Output

A µP reset input starts the µP in a known state. TheseµP supervisory circuits assert reset to prevent codeexecution errors during power-up, power-down, orbrownout conditions.

Reset asserts when VCCis below the reset threshold;once VCCexceeds the reset threshold, an internal timerkeeps the reset output asserted for the reset timeoutperiod. After this interval, reset output deasserts. Resetoutput is guaranteed to be in the correct logic state forVCC≥1V.

Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)

Many µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or externallogic circuitry to initiate a reset. A logic low on MRasserts reset. Reset remains asserted while MRis low,and for the reset active timeout period (tRP) after MRreturns high. This input has an internal 63k pullupresistor (1.56k for MAX6390), so it can be left uncon-nected if it is not used. MRcan be driven with TTL orCMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MRtoGND to create a manual-reset function; externaldebounce circuitry is not required. If MRis driven fromlong cables or if the device is used in a noisy environ-ment, connecting a 0.1µF capacitor from MRto GNDprovides 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, resetasserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESETIN (shown in Figure 1). Reset asserts when either VCCor RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:

VINTH= VTHRST (R1/R2 + 1)where VTHRST= +1.27V. To simplify the resistor selec-tion, 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 lossin accuracy.

___________Applications Information

In addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, theMAX6381–MAX6390 are relatively immune to short dura-tion negative-going VCCtransients (glitches).

The Typical Operating Characteristicssection shows theMaximum Transient Durations vs. Reset ComparatorOverdrive, for which the MAX6381–MAX6390 do notgenerate a reset pulse. This graph was generated using

Negative-Going VCCTransients

6_______________________________________________________________________________________

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

does not work with the open-drain outputs of theMAX6383/MAX6386/MAX6389/MAX6390. The resistorvalue used is not critical, but it must be small enoughnot to load the reset output when Vreset threshold. For most applications, 100kCCis above the is ade-quate.

a negative-going pulse applied to VCC, starting abovethe actual reset threshold and ending below it by themagnitude indicated (reset comparator overdrive). Thegraph indicates the typical maximum pulse width a neg-ative-going VCCtransient may have without causing areset pulse to be issued. As the magnitude of the tran-sient increases (goes farther below the reset threshold),the maximum allowable pulse width decreases. A 0.1µFcapacitor mounted as close as possible to VCCprovidesadditional transient immunity.

Ensuring a Valid RESETOutput Down to VCC= 0V

The MAX6381–MAX6390 are guaranteed to operateproperly down to V

valid reset levels down to VCC= 1V. In applications that requireCC= 0V, a pulldown resistorto active-low outputs (push/pull only, Figure 2) and apullup resistor to active-high outputs (push/pull only)will ensure that the reset line is valid while the reset out-put can no longer sink or source current. This scheme

_______________________________________________________________________________________7

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381–MAX6390

Selector Guide

Note:Insert reset threshold suffix (see Reset Threshold table)after "XR", "XS", or "LT." Insert reset timeout delay (see ResetTimeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.+Denotes a lead-free package.

8

_______________________________________________________________________________________

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

Pin Configurations (continued)

Chip Information

TRANSISTOR COUNT: 647PROCESS: BiCMOS

_______________________________________________________________________________________9

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381–MAX6390

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 .)

10______________________________________________________________________________________

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to ______________________________________________________________________________________11

MAX6381–MAX6390

SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits90

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to 36XAM–1836XAM12______________________________________________________________________________________

SC70/µDFN, Single/Dual Low-Voltage,

Low-Power µP Reset Circuits

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to Revision History

Pages changed at Rev 4: Title on all pages, 1, 2, 5,

7–13

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. 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____________________13©2007 Maxim Integrated Products

is a registered trademark of Maxim Integrated Products, Inc.

MAX6381–MAX6390