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19-1145; Rev 5; 4/08
Programmable Reset ICs
5-Pin, Multiple-Input,The MAX6305–MAX6313 CMOS microprocessor (µP)oSmall 5-Pin SOT23 Package
supervisory circuits are designed to monitor more thanone power supply. Ideal for monitoring both 5V andoPrecision Factory-Set VCCReset Thresholds;3.3V in personal computer systems, these devicesAvailable in 0.1V Increments from 2.5V to 5Vassert a system reset if any of the monitored suppliesoImmune to Short VCCTransients
falls outside the programmed threshold. Low supplyoGuaranteed RESETValid to VCC= 1Vcurrent (15µA) and a small package suit them foroGuaranteed Over Temperatureportable applications. The MAX6305–MAX6313 arespecifically designed to ignore fast transients on o8µA Supply Current
any monitored supply.
oFactory-Set Reset Timeout Delay from These devices are available in a SOT23-5 package,1ms (min) to 1120ms (min)have factory-programmed reset thresholds from 2.5V tooNo External Components5.0V (in 100mV increments), and feature four power-onoManual Reset Input
reset timeout periods. Ten standard versions are avail-oUnder/Overvoltage Supply Monitoring
able. Contact the factory for availability of non standardversions.
Portable ComputersComputersControllers
Intelligent Instruments
MAX6313 are available with factory-set VCCreset thresholds from2.5V to 5V, in 0.1V increments. Insert the desired nominal resetPortable/Battery-Powered Equipmentthreshold (from Table 1) into the blanks following the letters UK.All parts also offer factory-programmed reset timeout periods.Multivoltage Systems: 3V/5V, 5V/12V, 5V/24VInsert the number corresponding to the desired nominal timeoutEmbedded Control Systems
period index following the “D” in the part number (D1 = 1ms min,D2 = 20ms min, D3 = 140ms min, and D4 = 1120ms min). Thereare 10 standard versions with a required order increment of 2,500pieces. Sample stock is generally held on the standard versionsPin Configurations and Typical Operating Circuit appear at
only (see Standard Versions table). Required order increment isend of data sheet.
10,000 pieces for non-standard versions. Contact factory foravailability of non-standard versions. All devices available in tape-Ordering Information continued at end of data sheet.and-reel only.
Standard Versions Table appears 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 Table
________________________________________________________________Maxim Integrated Products
1
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MAX6305–MAX6313
5-Pin, Multiple-Input, Programmable Reset ICs
MAX6305–MAX6313
ABSOLUTE MAXIMUM RATINGS
VCC...........................................................................-0.3V to +6VAll Other Pins..............................................-0.3V to (VCC+ 0.3V)Input/Output Current, All Pins.............................................20mARate of Rise, VCC............................................................100V/µsContinuous Power Dissipation (TA= +70°C)
SOT23-5 (derate 7.1mW/°C above +70°C).................571mW
Operating Temperature Range
MAX63_ _UK _ _D_-T.........................................0°C to +70°CMAX63_ _EUK _ _D_-T...................................-40°C to +85°CStorage Temperature Range.............................-65°C to +160°CLead Temperature (soldering, 10sec).............................+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= +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, VCC = (VTH+ 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/
5-Pin, Multiple-Input, Programmable Reset ICs
ELECTRICAL CHARACTERISTICS (continued)
VCC= +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, VCC = (VTH+ 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/
Note 2: The MAX6305/MAX6308/MAX6311 switch from undervoltage reset to normal operation between 1.5V < VCC< 2.5V.
Note 3: The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 monitor VCCthrough an internal factory-trimmed voltage
pider, which programs the nominal reset threshold. Factory-trimmed reset thresholds are available in approximately100mV increments from 2.5V to 5V (Table 1).
Note 4:Guaranteed by design.
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MAX6305–MAX6313
5-Pin, Multiple-Input, Programmable Reset ICsMAX6305–MAX6313
__________________________________________Typical Operating Characteristics
(VCC= +5V, TA = +25°C, unless otherwise noted.)
OVRST IN RISING PROPAGATIONDELAY vs. TEMPERATURE(OVERVOLTAGE RESET INPUT)
SUPPLY CURRENTvs. TEMPERATURE
9.0SUPPLY CURRENT (μA)
8.58.07.57.06.56.05.55.0
-60
-40
-20
20
40
60
80
100
TEMPERATURE (°C)VCC FALLING PROPAGATION DELAY
vs. TEMPERATURE
8070PROPAGATION DELAY (ns)
6050403020100-60
-40
-20
20
40
60
80
100
TEMPERATURE (°C)7060PROPAGATION DELAY (ns)
50403020100-60
-40-20020406080100
TEMPERATURE (°C)
RST IN_ FALLING PROPAGATIONDELAY vs. TEMPERATURE
RESET TIMEOUTvs. TEMPERATURE
6305 TOC05
RESET THRESHOLDvs. TEMPERATURE
NORMALIZED RESET THRESHOLD (V/V)
1.0081.0061.0041.0021.0000.9980.9960.9940.9920.990
-60
-40
-20
20
40
60
80
100
6305 TOC06
120RST IN_ PROPAGATION DELAY (ns)
100806040200-60
-40
-20
20
40
60
80
1.101.08NORMALIZED RESET TIMEOUT
1.061.041.021.000.980.960.940.920.90
1.010
100-60-40-20020406080100
TEMPERATURE (°C)TEMPERATURE (°C)TEMPERATURE (°C)
MAXIMUM TRANSIENT DURATION vs.VCC
RESET THRESHOLD OVERDRIVE
MAXIMUM TRANSIENT DURATION vs.
OVRST IN THRESHOLD OVERDRIVE
MAXIMUM TRANSIENT DURATION vs.RST IN_ THRESHOLD OVERDRIVE
TRANSIENT DURATION (μs)
1000
10,000
TRANSIENT DURATION (μs)
1000
10,000
TRANSIENT DURATION (μs)
1000
10,000
100100
100
10
10
10
10
400
800
1200
OVERDRIVE, VTH - VCC (mV)
10
400
800
1200
OVERDRIVE, VOVRST IN - VREF (mV)
10
400
800
1200
OVERDRIVE, VREF - VRST IN (mV)
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9.5
5-Pin, Multiple-Input, Programmable Reset ICs
______________________________________________________________Pin Description
_______________Detailed Description
Reset Outputs
The MAX6305–MAX6313 CMOS microprocessor (µP)A µP’s reset input starts the µP in a known state. Thesesupervisory circuits are designed to monitor more thanµP supervisory circuits assert reset to prevent code-one power supply and issue a system reset when anyexecution errors during power-up, power-down, ormonitored supply falls out of regulation. The MAX6305/brownout conditions.
MAX6308/MAX6311 have two adjustable undervoltageRESET(MAX6305–MAX6310) and RESET (MAX6311/reset inputs (RST IN1 and RST IN2). The MAX6306/MAX6312/MAX6313) are guaranteed to be asserted atMAX6307/MAX6309/MAX6310/MAX6312/MAX6313 mon-a valid logic level for Vitor VCCthrough an internal, factory-trimmed voltageCharacteristics). Once all monitored voltages exceedCC> 1V (see Electricalpider. The MAX6306/MAX6309/MAX6312 have, intheir programmed reset thresholds, an internal timeraddition, an adjustable undervoltage reset input and akeeps reset asserted for the reset timeout period (tmanual-reset input. The internal voltage pider sets theafter this interval, reset deasserts.
RP);reset threshold as specified in the device part number(Table 1). The MAX6307/MAX6310/ MAX6313 feature anIf a brownout condition occurs (any or all monitored volt-adjustable undervoltage reset input (RST IN) and anages dip outside their programmed reset threshold),adjustable overvoltage reset input (OVRST IN) in additionreset asserts (RESET goes high; RESETgoes low). Anyto the factory-trimmed reset threshold on the Vtime any of the monitored voltages dip below their resetCCmoni-tor. Program the adjustable reset inputs with an externalthreshold, the internal timer resets to zero and resetresistor pider (see Adjustable Reset Inputs section).
asserts. The internal timer starts when all of the moni-tored voltages return above their reset thresholds, andreset remains asserted for a reset timeout period. TheMAX6305/MAX6306/MAX6307 feature an active-low,
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MAX6305–MAX6313
5-Pin, Multiple-Input, Programmable Reset ICsMAX6305–MAX6313
open-drain, N-channel output. The MAX6308/MAX6309/MAX6310 feature an active-low, complementary outputstructure that both sinks and sources current, and theMAX6311/MAX6312/MAX6313 have an active-high com-plementary reset output.
The MAX6305/MAX6308/MAX6311 switch from under-voltage lockout operation to normal operation between1.5V < VCC< 2.5V. Below 1.5V, VCCundervoltage-lockout mode asserts RESET. Above 2.5V, VCCnormal-operation mode asserts reset if RST IN_ falls below theRST IN_ threshold.
Manual-Reset Input
(MAX6306/MAX6309/MAX6312)
Many µP-based products require manual-reset capability,allowing an operator or external logic circuitry to initiate areset. A logic low on MRasserts reset. Reset remainsasserted while MRis low, and for a reset active timeoutperiod (tRP) after MRreturns high. This input has an inter-nal 63.5kΩpull-up resistor, so it can be left open if it is notused. MRcan be driven with TTL-logic levels in 5V sys-tems, with CMOS-logic levels in 3V systems, or with open-drain/collector output devices. Connect a normally openmomentary switch from MRto GND to create a manual-reset function; external debounce circuitry is not required.If MRis driven from long cables or if the device is used ina noisy environment, connecting a 0.1µF capacitor fromMRto ground provides additional noise immunity.
The MRpin has internal ESD-protection circuitry that maybe forward biased under certain conditions, drawingexcessive current. For example, assume the circuitry driv-ing MRuses a +5V supply other than VCC. If VCCdrops orbrowns out lower than +4.7V, MR’s absolute maximum rat-ing is violated (-0.3V to (VCC+ 0.3V)), and undesirablecurrent flows through the ESD structure from MRto VCC.To avoid this, it is recommended that the supply for the MRpin be the same as the supply monitored by VCC. In thisway, the voltage at MRwill not exceed VCC.
Adjustable Reset Inputs
The MAX6305–MAX6313 each have one or more resetinputs (RST IN_ /OVRST IN). These inputs are com-pared to the internal reference voltage (Figure 1).Connect a resistor voltage pider to RST IN_ such thatVRST IN_falls below VRSTH(1.23V) when the monitoredvoltage (VIN) falls below the desired reset threshold(VTH) (Figure 2). Calculate the desired reset voltagewith the following formula:
R1 + R2x V
VTH= ________RSTH
R2
Figure 1. Functional Diagram
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5-Pin, Multiple-Input, Programmable Reset ICs
Figure 2. Increasing Noise Immunity
Figure 3. Interfacing to µPs with Bidirectional Reset I/O
The ±25nA max input leakage current allows resistors onNegative-Going Vthe order of megohms. Choose the pull-up resistor in theIn addition to issuing a reset to the µP during power-up,CCTransients
pider to minimize the error due to the input leakage cur-power-down, and brownout conditions, these devicesrent. The error term in the calculated threshold is simply:
are relatively immune to short-duration, negative-going±25nA x R1
VCCtransients (glitches).
If you choose R1 to be 1MΩ, the resulting error isThe Typical Operating Characteristics show the±25 x 10-9x 1 x 106= ±25mV.
Maximum Transient Duration vs. VCCReset ThresholdLike the VOverdrive, for which reset pulses are not generated.MAX6309/MAX6310/MAX6312/MAX6313, the RST IN_CCvoltage monitors on the MAX6306/MAX6307/The graph was produced using negative-going pulses,inputs (when used with a voltage pider) are designed tostarting at Vignore fast voltage transients. Increase the noise immunitygrammed reset threshold by the magnitude indicatedTHmax, and ending below the pro-by connecting a capacitor on the order of 0.1µF between(reset threshold overdrive). The graph shows the maxi-RST IN and GND (Figure 2). This creates a single-polemum pulse width that a negative-going Vmay typically have without causing a reset pulse to beCCtransientlowpass filter with a corner frequency given by:
issued. As the amplitude of the transient increases (i.e.,f = (1/2π) / (R1 + R2)(R1 x R2 x C)
goes farther below the reset threshold), the maximumFor example, if R1 = 1MΩand R2 = 1.6MΩ, adding aallowable pulse width decreases.
0.1µF capacitor from RST IN_ to ground results in aRST IN_/OVRST IN are also immune to negative/positive-lowpass corner frequency of f = 2.59Hz. Note thatgoing transients (see Typical Operating Characteristics).adding capacitance to RST IN slows the circuit’s overallA 0.1µF bypass capacitor mounted close to the RST IN_,response time.
OVRST IN, and/or the V__________Applications Information
sient immunity.
CCpin provides additional tran-Interfacing to µPs with Ensuring a Valid RESET/RESET
Bidirectional Reset Pins
Output Down to VCC= 0V
Since the RESEToutput on the MAX6305/MAX6306/When VCCfalls below 1V, push/pull structured RESET/MAX6307 is open drain, these devices interface easilyRESET current sinking (or sourcing) capabilitieswith µPs that have bidirectional reset pins, such as thedecrease drastically. High-impedance CMOS-logicMotorola 68HC11. Connecting the µP supervisor’sinputs connected to RESETcan drift to undeterminedRESEToutput directly to the microcontroller’s RESETvoltages. This presents no problem in most applica-pin with a single pull-up resistor allows either device totions, since most µPs and other circuitry do not operateassert reset (Figure 3).
with VCCbelow 1V. In those applications where RESETmust be valid down to 0V, adding a pull-down resistorbetween RESETand ground sinks any stray leakage
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MAX6305–MAX6313
5-Pin, Multiple-Input, Programmable Reset ICsMAX630
5–MAX6313
currents, holding RESETlow (Figure 4). The pull-downresistor’s value is not critical; 100kΩis large enough notto load RESETand small enough to pull RESETtoground. For applications where RESET must be valid toVCC, a 100kΩpull-up resistor between RESET and VCCwill hold RESET high when VCCfalls below 1V (Figure 5).Since the MAX6305/MAX6306/MAX6307 have open-drain, active-low outputs, they typically use a pull-upresistor. With these devices and under these conditions(VCC< 1V), RESETwill most likely not maintain anactive condition, but will drift toward a nonactive leveldue to the pull-up resistor and the RESEToutput’sreduction in sinking capability. These devices are notrecommended for applications that require a validRESEToutput below 1V.
Table 1. Factory-Trimmed ResetThresholds*
Figure 4. Ensuring RESETValid to VCC= 0V
* Factory-trimmed reset thresholds are available in approximately100mV increments with a ±1.5% room-temperature variance.
Figure 5. Ensuring RESET Valid to VCC= 0V
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____________________________________________________________
5-Pin, Multiple-Input, Programmable Reset ICs
The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/
MAX6313 are available with factory-set VCCreset thresholds from2.5V to 5V, in 0.1V increments. Insert the desired nominal resetthreshold (from Table 1) into the blanks following the letters UK.Chip Information
All parts also offer factory-programmed reset timeout periods.TRANSISTORCOUNT: 800
Insert the number corresponding to the desired nominal timeoutperiod index following the “D” in the part number (D1 = 1ms min,D2 = 20ms min, D3 = 140ms min, and D4 = 1120ms min). Thereare 10 standard versions with a required order increment of 2,500pieces. Sample stock is generally held on the standard versionsonly (see Standard Versions table). Required order increment is10,000 pieces for non-standard versions. Contact factory for avail-ability of non-standard versions. 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.
_______________________________________________________________________________________9
MAX6305–MAX6313
5-Pin, Multiple-Input, Programmable Reset ICsMAX6305–MAX6313
Pin Configurations
Package Information
For the latest package outline information, go to.10______________________________________________________________________________________
5-Pin, Multiple-Input, Programmable Reset ICs
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 ____________________11©2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
MAX6305–MAX6313
