LM3724EM5-3.08/NOPB

LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 LM3722/LM3723/LM3724 5-Pin Microprocessor Reset Circuits Check for Samples: LM3722, LM3723, LM3724 FEATURES DESCRIPTION • The LM3722/LM3723/LM3724 microprocessor supervisory circuits monitor the power supplies in microprocessor and digital systems. They provide a reset to the microprocessor during power-up, powerdown, brown-out conditions, and manual reset. 1 2 • • • • • • Precise Monitoring of 2.5V, 3.3V, and 5V Supply Voltages Fully Specified Over Temperature – Industrial: −40°C to +85°C – Extended: −40°C to +125°C 100 ms Minimum Power-On Reset pulse Width, 190 ms Typical: – Active-Low RESET Output (LM3722) – Active-High RESET Output (LM3723) – Active-Low RESET Open Drain Output (LM3724) Guaranteed RESET Output Valid for VCC ≥ 1V Low Supply Current, 6µA Typical Power Supply Transient Immunity Compatible with MAX811/812 Applications APPLICATIONS • • • • • The LM3722/LM3723/LM3724 asserts a reset signal whenever the supply decreases below the factoryprogrammed reset threshold. Reset will be asserted for at least 100ms even after VCC rises above the reset threshold. The LM3722 has an active-low RESET push-pull output. The LM3723 has an active-high RESET pushpull output. The LM3724 has an active-low open-drain RESET output. Three standard reset voltage options are available, suitable for monitoring 5V, 3.3V, and 2.5V supply voltages. Additional reset voltages are also available; contact Texas Instruments for details. With a low supply current of only 6µA, the LM3722/LM3723/LM3724 are ideal for use in portable equipment. The LM3722/LM3723/LM3724 are available in the 5-pin SOT-23 package. Microprocessor Systems Computers Controllers Intelligent Instruments Portable/Battery-Powered Equipment Typical Application Circuits VCC VCC VCC VCC VCC VCC RL LM3722 LM3723 MR PUSHBUTTON SWITCH RESET *(RESET) PP RESET INPUT GND Figure 1. Typical Application Circuit MR GND PP LM3724 PUSHBUTTON SWITCH RESET GND RESET INPUT GND Figure 2. Typical Application Circuit with RL Connection 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2001–2013, Texas Instruments Incorporated LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com Connection Diagram 5 VCC GND 1 GND 2 LM3722 LM3723 LM3724 RESET 3 *(RESET) 4 MR *( ) are for LM3723 Figure 3. SOT-23-5 PIN DESCRIPTIONS PIN NAME 1 GND Ground reference GND Ground reference, device substrate, connect to ground. 2 3 FUNCTION RESET LM3722/LM3724 RESET LM3723 Active-low output. RESET remains low while VCC is below the reset threshold voltage, and for 190 ms after VCC rises above the reset threshold voltage. Active-high output. RESET remains high while VCC is below the reset threshold, and for 190 ms after VCC rises above the reset threshold. 4 MR Active-low input. Reset is asserted whenever this pin is pulled low and remains asserted for 190 ms after the MR pin goes high. May be left open. 5 VCC Supply Voltage (+5V, +3.3V, or +2.5V, nominal) Block Diagram VCC OPEN for LM3724 CONNECT for LM3722/LM3723 Reset Comparator + 22k Low Line Comparator RESET/ RESET Reset Logic and One-Shot Timer Manual Reset Comparator + MR 1.225V Reference Figure 4. LM3722/LM3723/LM3724 Block Diagram 2 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (1) (2) −0.3V to 6.0V VCC, MR −0.3V to (VCC+ 0.3V) RESET, RESET Input Current, VCC Pin 20mA Output Current, RESET, RESET Pin 20mA ESD Rating (3) 2kV Continuous Power Dissipation (TA = +70°C) SOT-23 (4) 320mW Operating Temperature Range Industrial: −40°C to +85°C Extended: −40°C to +125°C Maximum Junction Temperature 125°C −65°C to +160°C Storage Temperature Range Lead Temperature (soldering, 10sec) (1) (2) (3) (4) +300°C Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which the device operates correctly. Operating ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications. The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. At elevated temperatures, devices must be derated based on package thermal resistance. The device in the SOT-23-5 package must be derated at 4.5mW/°C at ambient temperatures above 70°C. The device has internal thermal protection. Electrical Characteristics Typical values are at TA = +25°C. Limits with standard typeface are for TA = +25°C, and limits in boldface type apply for the operating temperature range (−40°C to +85°C) for LM372_IM5X, and (−40°C to +125°C) for LM372_EM5X, unless otherwise noted. (1) Symbol VCC ICC VTH VTH Tempco Parameter (2) (3) Min Reset Threshold VCC to Reset Delay (2) Max V µA VCC = 5.5V 8 15 LM372 _ -3.08 VCC = 3.6V 7 10 LM372 _ -2.32 VCC = 2.5V 6 10 LM372 _ -4.63 4.54 4.50 4.63 4.72 4.75 LM372 _ -3.08 3.03 3.00 3.08 3.14 3.15 LM372 _ -2.32 2.27 2.25 2.32 2.37 2.40 VCC = VTH to (VTH − 100mV) tRP Reset Active Timeout Period 100 tMR MR Minimum Pulse Width 10 tMD MR to Reset Propagation Delay (3) Units 5.5 LM372 _ -4.63 Reset Threshold Temperature Coefficient tRD Typ 1.0 Supply Current (ILOAD = 0A) MR Glitch Immunity (1) Conditions VCC Range V 30 ppm/°C 20 µs 190 560 ms µs 2 µs 100 ns Production testing done at TA = +25°C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) methods. RESET Output for LM3722 and LM3724, RESET output for LM3723. Glitches of 100 ns or less typically will not generate a reset pulse. Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 Submit Documentation Feedback 3 LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com Electrical Characteristics (continued) Typical values are at TA = +25°C. Limits with standard typeface are for TA = +25°C, and limits in boldface type apply for the operating temperature range (−40°C to +85°C) for LM372_IM5X, and (−40°C to +125°C) for LM372_EM5X, unless otherwise noted. (1) Symbol Parameter VIH VIL VIH Conditions Min VCC > VTH(MAX), LM372_ -4.63 VCC > VTH(MAX), LM372_ -3.08, LM372_ -2.32 0.7 VCC VOL VOH 22 VCC = VTH min, ISINK = 1.2mA, (LM37222.32/3.08) 0.3 VCC = VTH min, ISINK = 3.2mA, (LM3722-4.63) 0.4 VCC > 1V, ISINK = 50µA 0.3 VCC > VTH max, ISOURCE = 500µA, (LM37222.32/3.08) 0.8VCC VCC > VTH max, ISOURCE = 800µA, (LM3722-4.63) VCC−1.5 V V VCC = VTH max, ISINK = 1.2mA (LM3723 -2.32/3.08) 0.3 VCC = VTH max, ISINK = 3.2mA (LM3723 -4.63) 0.4 RESET Output Voltage Low (LM3723) VOH RESET Output Voltage High (LM3723) 1.8V < VCC < VTH min, ISOURCE = 150µA VOL RESET Output Voltage Low (LM3724) VCC = VTH min, ISINK = 1.2 mA (LM3724 -2.32/3.08) 0.3 VCC = VTH min, ISINK = 3.2 mA (LM3724 -4.63) 0.4 VCC > 1V, ISINK = 50µA 0.3 0.8VCC RESET Output Leakage Current VCC > VTH, RESET = 5.5V (LM3724) Submit Documentation Feedback V kΩ VOL IIN 4 RESET Output Voltage High (LM3722) Units 0.25 VCC MR Pull-Up Resistance RESET Output Voltage Low (LM3722) Max 0.8 MR Input Threshold VIL Typ 2.3 V V 0.5 V µA Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 Typical Performance Characteristics Supply Current vs VCC Supply Current vs Temperature 10 9 VCC = 5.5V 8 SUPPLY CURRENT (PA) 7 ICC (PA) 6 5 4 3 2 8 6 VCC = 3.6V 4 VCC = 2.5V 2 1 0 -40 0 0 1 2 4 3 5 6 10 35 60 TEMPERATURE (oC) Figure 5. Figure 6. Reset Timeout vs VCC Reset Timeout vs Temperature 1.05 85 210 200 RESET TIMEOUT (ms) NORMALIZED RESET TIMEOUT -15 VCC (V) 1.025 1 0.975 190 180 170 160 150 -40 0.95 2 3 5 4 6 -20 0 20 40 60 80 TEMPERATURE (oC) VCC (V) Figure 7. Figure 8. Normalized VTH vs Temperature LM3724 VOL vs Current 700 1.005 1.004 VCC = 2.5V 600 500 VCC = 3.3V 1.001 VOL (mV) NORMALIZED VTH 1.003 1.002 1.000 0.999 400 VCC = 5V 300 200 0.998 0.997 100 0.996 0.995 -40 -20 40 0 20 60 TEMPERATURE (oC) 80 0 0.1 Figure 9. 0.3 3.0 1.0 SINK CURRENT (mA) 10.0 Figure 10. Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 Submit Documentation Feedback 5 LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) LM3724 Low VCC Characteristics 700 RESET VOLTAGE (mV) 600 10 k: Pull-Up Resistor 500 400 300 200 100 0 0.0 0.5 1.0 1.5 2.0 VCC (V) Figure 11. 6 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 Timing Diagram Figure 12. Timing Diagram Circuit Information RESET OUTPUT The reset input of a µP initializes the device into a known state. The LM3722/LM3723/LM3724 microprocessor voltage monitoring circuits assert a forced reset output to prevent code execution errors during power-up, powerdown, and brownout conditions. RESET is guaranteed valid for VCC ≥ 1V. Once VCC exceeds the reset threshold, an internal timer maintains the output for the reset timeout period. After this interval, reset goes high and the microprocessor initializes itself into a known state. The LM3722 and LM3724 offer an active-low RESET; the LM3723 offers an active-high RESET. As VCC drops below the reset threshold (such as during a brownout), the reset activates (see the NEGATIVEGOING VCC TRANSIENTS section). When VCC again rises above the reset threshold, the internal timer starts. Reset holds until VCC exceeds the reset threshold for longer than the reset timeout period. After this time, reset releases. Additionally, the Manual Reset input (MR) will initiate a forced reset. See the MANUAL RESET INPUT (MR) section. The LM3722/LM3723/LM3724 reset outputs ignore short duration glitches on VCC and MR. See the Applications Information section for details. RESET THRESHOLD The LM3722/LM3723/LM3724 are available with reset voltages of 4.63V, 3.08V, and 2.32V which are suitable for monitoring 5.0V, 3.3V, and 2.5V supplies respectively. Other reset thresholds in the 2.20V to 5.0V range, in 10 mV steps, are available; contact Texas Instruments for details. Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 Submit Documentation Feedback 7 LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com MANUAL RESET INPUT (MR) Many µP-based products require a manual reset capability, allowing the operator to initiate a reset. The MR input is fully debounced and provides an internal 22 kΩ pull-up. When the MR input is pulled below VIL (0.25VCC) for more than 100 ns, reset is asserted after a typical delay of 2 µs. Reset remains active as long as MR is held low, and releases after MR rises above VIH and the reset timeout period expires. Use MR with digital logic to assert reset or to daisy chain supervisory circuits. APPLICATIONS INFORMATION BENEFITS OF PRECISION RESET THRESHOLDS A microprocessor supply supervisor must provide a reset output within a predictable range of the supply voltage. A common threshold range is between 5% and 10% below the nominal supply voltage. The 4.63V, 3.08V and 2.32V options of the LM3722/LM3723/LM3724 use highly accurate circuitry to ensure that the reset threshold occurs only within this range (for 5.0V, 3.3V and 2.5V supplies). Table 1 shows how the standard reset thresholds apply to 5.0V, 3.3V, and 2.5V nominal supply voltages. Table 1. Monitored Tolerance Table Supply Voltage Reset Threshold 2.5V 3.3V 4.63 ± % 5.0V 90.8-94.4% 3.08 ± % 91.8-95.2% 2.32 ± % 90.8-94.8% ENSURING A VALID RESET OUTPUT DOWN TO VCC = 0V When VCC falls below 1V, the LM3722 RESET output is unable to sink the rated current. A high-impedance CMOS logic input connected to RESET can therefore drift to undetermined voltages. To prevent this situation, a 100kΩ resistor should be connected from the RESET output to ground, as shown in Figure 13. A 100kΩ pull-up resistor to VCC is also recommended for the LM3723, if RESET is required to remain valid for VCC < 1V. Figure 13. Circuit for RESET Valid from VCC = 0V OPEN DRAIN OUTPUT (LM3724) An open drain output allows easy paralleling of multiple microprocessor reset circuits without requiring additional logic gates. Open drain outputs also allow interfacing devices of differing logic levels or families, since the output pull-up resistor may be connected to any supply voltage up to 5.5V, regardless of LM3724 VCC. The pull up resistor is calculated so that maximum current flow into RESET is less than 10 mA when activated. The resistor must be small enough so that the leakage current of all connected devices does not create an excessive voltage drop when the output is not activated. A resistor value of 100 kΩ will generally suffice. 8 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 NEGATIVE-GOING VCC TRANSIENTS The LM3722/LM3723/LM3724 are relatively immune to short negative-going transients or glitches on VCC. Figure 14 shows the maximum pulse width a negative-going VCC transient can have without causing a reset pulse. In general, as the magnitude of the transient increases, going further below the threshold, the maximum allowable pulse width decreases. Typically, a VCC transient that goes 125 mV below the reset threshold and lasts 40 µs or less will not cause a reset pulse. A 0.1 µF bypass capacitor mounted as close as possible to the VCC pin will provide additional transient rejection. 600 Overdrive (mV) 500 400 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Max Transient Duration (Ps) Figure 14. Maximum Transient Duration without Causing a Reset Pulse vs. Reset Comparator Overdrive INTERFACING TO µPS WITH BIDIRECTIONAL RESET PINS Microprocessors with bidirectional reset pins, such as the Motorola 68HC11 series, can be connected to the LM3722 RESET output. To ensure a correct output on the LM3722 even when the microprocessor reset pin is in the opposite state, connect a 4.7kΩ resistor between the LM3722 RESET output and the µP reset pin, as shown in Figure 15. Buffer the LM3722 RESET output to other system components. Typical Application Circuits Figure 15. Interfacing to Microprocessors with Bidirectional Reset I/O Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 Submit Documentation Feedback 9 LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com VIN IN VOUT OUT + LM2941 SD GND 24.9k 2.2PF ADJ 7.15k 14.7k 11.5k VOUT = 3.3V VCC VIN(TRIP) = 5.0V LM3722 RESET MR OVERRIDE 5V 4V VIN 3.3V VOUT tRP RESET Figure 16. Regulator/Switch with Long-Term Overvoltage Lockout Prevents Overdissipation in Linear Regulator 3.3V VCC RESET LM3722 MR RESET GND tRP tRP tRP Mechanical Switch MR Figure 17. LM3722 Switch Debouncer 10 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 LM3722, LM3723, LM3724 www.ti.com SNVS154E – MAY 2001 – REVISED MARCH 2013 MTP50P03HDL VIN VOUT LOAD C VCC RESET R LM3723 GND VIN VOUT RESET tRP Figure 18. LM3723 Power-On Delay Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 Submit Documentation Feedback 11 LM3722, LM3723, LM3724 SNVS154E – MAY 2001 – REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision D (March 2013) to Revision E • 12 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 11 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM3722 LM3723 LM3724 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM3724EM5-3.08/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 R63B LM3724EM5-4.63/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 R62B LM3724IM5-2.32/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 R50B LM3724IM5-3.08/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 R53B LM3724IM5-4.63/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 R55B LM3724IM5X-3.08/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 R53B (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of