Features • Standard Reset Threshold voltage: 3.08V • Custom Reset Threshold voltages: For other voltages between 2.2V and 5.0V in 10mV increments, contact National Semiconductor Corp. • No external components required • Manual-Reset input • ^RESET output • Precision supply voltage monitor • Factory programmable Reset and Watchdog Timeout Delays • Separate Watchdog output • Separate Power Fail comparator • Available in micro SMD package for minimum footprint • ±0.5% Reset threshold accuracy at room temperature • ±2% Reset threshold accuracy over temperature extremes • Reset assertion down to 1V VCC • 28 µA VCC supply current Description The LM3712 series of microprocessor supervisory circuits provide the maximum flexibility for monitoring power supplies and battery controlled functions in systems without backup batteries. The LM3712 series are available in a 9-bump micro SMD package. Built-in features include the following: Reset: Reset is asserted during power-up, power-down, and brownout conditions. ^RESET is guaranteed down to VCC of 1.0V. Manual Reset Input: An input that asserts reset when pulled low. Power-Fail Input: A 1.225V threshold detector for power fail warning, or to monitor a power supply other than VCC. Watchdog Timer: The WDI (Watchdog Input) monitors one of the µP's output lines for activity. If no output transition occurs during the watchdog timeout period, the watchdog output ( ^WDO) pulls low. Applications • Embedded Controllers and Processors • Intelligent Instruments • Automotive Systems • Critical µP Power Monitoring

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Datasheet

Title		Size	Date	Other Language
	LM3712 Microprocessor Supervisory Circuits with Separate Watchdog Timer Output, Power Fail Input and Manual Reset	311 Kbytes	9-Jun-08

Featured Application Notes

Title		Size	Date	Other Language
	AN-1772: Application Note 1772 LM3691 Evaluation Board	567 Kbytes	14-May-08

More Application Notes

Title		Size	Date	Other Language
	AN-87: Application Note 87 Comparing the High Speed Comparators	249 Kbytes	1-Oct-02
	AN-1772: Application Note 1772 LM3691 Evaluation Board	567 Kbytes	14-May-08
	AN-271: Application Note 271 Applying the New CMOS MICRO-DAC	230 Kbytes	4-Oct-04	日本語
	AN-294: Application Note 294 Special Sample and Hold Techniques	233 Kbytes	4-Oct-04

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM3712XQTP-308/NOPB RoHS		Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 499	$1.20 each at 1K+ pcs	reel of 250
LM3712XQTPX-308/NOPB RoHS		Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.20 each at 1K+ pcs	reel of 3000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM3712XQBP-308	NONE	NATIONAL SEMICONDUCTOR	24 Jul 2009
LM3712XQTP-308	LM3704XCMM-308	National Semiconductor	30 Nov 2009
LM3712XQTPX-308	LM3704XCMMX-308	National Semiconductor	30 Nov 2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3712XQTP-308	CS065	2	38968	52	0	4402000	1	1249079519
LM3712XQTPX-308	CS065	2	38968	52	0	4402000	1	1249079519

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

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Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM3712XQBP-308	NONE	NATIONAL SEMICONDUCTOR	24 Jul 2009
LM3712XQTP-308	LM3704XCMM-308	National Semiconductor	30 Nov 2009
LM3712XQTPX-308	LM3704XCMMX-308	National Semiconductor	30 Nov 2009