Obsolete Device TC1278/TC1279 3-Pin Reset Monitors for 5V Systems Features General Description • • • • • • • • The TC1278/TC1279 are cost-effective system supervisor circuits designed to monitor VCC in digital systems and provide a reset signal to the host processor when necessary. No external components are required. The open-drain output uses an internal pull-up resistor of approximately 6 kΩ. Precision VCC Monitor for 5.0V System Supplies 250 ms Minimum RESET Output Duration Output Valid to VCC = 1.2V VCC Transient Immunity Small 3-Pin SOT-23 Package No External Components Internal Pull-up Resistor Available in 3 different voltage detection levels: - 4.625V (typ.), -5 suffix - 4.375V (typ.), -10 suffix - 4.125V (typ.), -15 suffix Applications • • • • Computers Embedded Systems Battery Powered Equipment Critical µP Power Supply Monitoring Package Type 3-Pin SOT-23 (TC1278) RESET 1 (TC1279) RESET Typical Operating Circuit VCC The reset output is driven active within 5 µs of VCC falling through the reset voltage threshold. RESET is maintained active for a minimum of 250 ms after VCC rises above the reset threshold. The TC1278 has an active-high RESET output, while the TC1279 has an active-low RESET output, with both devices having an open-drain output stage. The output is valid down to VCC = 1.2V. Both devices are available in a 3-Pin SOT- 23 package. Internal Pull-up 6 kΩ Resistor – TC1278 TC1279 RESET VCC 3 GND 2 + VREF TC1279 GND TC1278 has an active-high RESET output. © 2007 Microchip Technology Inc. DS21384D-page 1 TC1278/TC1279 1.0 ELECTRICAL CHARACTERISTICS † Stresses above 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 above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings † Supply Voltage (VCC to GND) ..............................+6.0V RESET, RESET...........................-0.3V to (VCC + 0.3V) Input Current, VCC ..............................................20 mA Output Current, RESET......................................20 mA Power Dissipation (TA ≤ 70°C) 3-Pin SOT-23 (derate 4mW/°C above +70°C) ................................................................230 mW Operating Temperature Range.............-40°C to +85°C Storage Temperature Range ..............-65°C to +150°C DC CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, TA = -40°C to +85°C. Typical values are at TA = +25°C. Parameters Sym Min Typ Max Units Conditions Supply Voltage VCC 1.2 — 5.5 V Note 1 Low Level @ RESET (TC1278) RESET (TC1279) VOL — — 0.4 V Note 1 Output Current @ 0.4 Volts IOL +8 — — mA Note 2 — 0.9 2.0 mA VCC > VCCTP(MAX), RESET = 1, (Note 3) — — 40 µA VCC > VCCTP(MAX), RESET = 1, Note 4 Operating Current: TC1278 ICC1 TC1279 Operating Current: TC1278 ICC2 TC1279 — — 40 µA VCC < VCCTP(MIN), RESET = 0, (Note 4) — 0.9 2.0 mA VCC < VCCTP(MIN), RESET = 0, (Note 3) VCC Trip Point (TC1278/9-5) VCCTP-5 4.50 4.625 4.74 V Note 1 VCC Trip Point (TC1278/9-10) VCCTP-10 4.25 4.375 4.49 V Note 1 VCC Trip Point (TC1278/9-15) VCCTP-15 4.00 4.125 4.24 V Note 1 COUT — 9 — pF RP 3 6 9 kΩ Output Capacitance Internal Pull-Up Resistor Note 1: 2: 3: 4: All voltages referenced to ground. A 1 kΩ external resistor may be required in some applications for proper operation of the microprocessor reset control circuit when using the TC1279. VCC = 1.8V. Operating current is specified with the open-drain output in the active (“ON”) condition. Operating current is specified with the open-drain output in the non-active (“OFF”) condition. DS21384D-page 2 © 2007 Microchip Technology Inc. TC1278/TC1279 AC CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, TA = -40°C to +85°C. Typical values are at TA = +25°C. Parameters Sym Min Typ Max Units RESET Active Time tRST 250 350 450 ms VCC Detect to RESET (TC1279) tRPD1 — 2 5 µs Figure 3-2 VCC Detect to RESET (TC1278) tRPD2 — 2 5 µs Figure 3-4 VCC Slew Rate (4.75V-4.00V) tF 300 — — µs Figure 3-2, Figure 3-4 VCC Slew Rate (4.00V-4.75V) tR 0 — — ns Figure 3-1, Figure 3-3 VCC Detect to RESET (TC1279) tRPU1 250 350 450 ms Figure 3-1 VCC Detect to RESET (TC1278) tRPU2 250 350 450 ms Figure 3-3 © 2007 Microchip Technology Inc. Conditions DS21384D-page 3 TC1278/TC1279 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: 2.1 PIN FUNCTION TABLE Pin No. Symbol Function 1 RESET (TC1279) RESET output 1 RESET (TC1278) RESET output 2 VCC Supply voltage (1.2V to 5.5V). 3 GND Ground. RESET (TC1279) RESET output remains low while VCC is below the reset voltage threshold, and for 350 ms (250 ms min.) after VCC rises above reset threshold. The output stage of the TC1279 is open-drain. 2.2 2.3 VCC Supply voltage (1.2V to 5.5V). 2.4 Ground Device ground. RESET (TC1278) RESET output remains high while VCC is below the reset voltage threshold, and for 350 ms (250 ms min.) after VCC rises above reset threshold. The output stage of the TC1278 is open-drain. DS21384D-page 4 © 2007 Microchip Technology Inc. TC1278/TC1279 3.0 APPLICATIONS INFORMATION 3.1 Operation – Power Monitor The TC1278/TC1279 provide the function of detecting out-of-tolerance power supply conditions and warning a processor-based system of impending power failure. When VCC is detected as out-of-tolerance, the RESET signal is asserted. On power-up, RESET is kept active for approximately 350 ms after the power supply has reached the selected tolerance. This allows the power supply and microprocessor to stabilize before RESET is released. 4.75V VCCTP VCCTP(MIN) VCC tRPU2 VOL FIGURE 3-3: Diagram. TC1278 Power-Up Timing VCC VOH FIGURE 3-1: Diagram. tF VCC tRPU1 RESET 4.74V VCCTP TC1279 Power Up Timing 4.75V VCCTP VOH RESET FIGURE 3-4: Timing Diagram. 4.00V 4.00V tRPD2 tF VCC VCCTP(MAX) VCCTP RESET tR 4.00V tR RESET SLEWS WITH VCC TC1278 Power-Down tRPD1 RESET VOL FIGURE 3-2: Timing Diagram. TC1279 Power-Down © 2007 Microchip Technology Inc. DS21384D-page 5 TC1278/TC1279 VCC Transient Rejection The TC1278/TC1279 provides accurate VCC monitoring and reset timing during power-up, power-down, and brownout/sag conditions. Furthermore, it rejects negative-going transients (glitches) on the power supply line. Figure 3-5 shows the maximum transient duration vs. maximum negative excursion (overdrive) for glitch rejection. Any combination of duration and overdrive that lays under the curve will not generate a reset signal. Combinations above the curve are detected as a brownout or power-down. Transient immunity can be improved by adding a capacitor in close proximity to the VCC pin of the TC1278/TC1279. VCC VCCTP Overdrive MAXIMUM TRANSIENT DURATION (µsec) 3.2 Duration 5 TA = +25°C 4 3 2 TC1278/9 1 0 1 5 1000 100 RESET COMPARATOR OVERDRIVE, [ VCCTP - VCC] (mV) FIGURE 3-5: Maximum Transient Duration vs. Overdrive For Glitch Rejection At +25°C. DS21384D-page 6 © 2007 Microchip Technology Inc. TC1278/TC1279 4.0 PACKAGING INFORMATION 4.1 Package Marking Information 3-Pin SOT-23 1 1 & 2 2 3 4 = part number code + temperature range and voltage Part Number TC1278-5ENB Code PA TC1278-10ENB PB TC1278-15ENB PC TC1279-5ENB RA TC1279-10ENB RB TC1279-15ENB RC 3 represents year and 2-month code 4 represents production lot ID code © 2007 Microchip Technology Inc. DS21384D-page 7 TC1278/TC1279 3-Lead Plastic Small Outline Transistor (TT or NB) [SOT-23] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging b N E E1 2 1 e e1 D c A A2 φ A1 L Units Dimension Limits Number of Pins MILLIMETERS MIN NOM MAX N 3 Lead Pitch e 0.95 BSC Outside Lead Pitch e1 Overall Height A 0.89 – Molded Package Thickness A2 0.79 0.95 1.02 Standoff A1 0.01 – 0.10 1.90 BSC 1.12 Overall Width E 2.10 – 2.64 Molded Package Width E1 1.16 1.30 1.40 Overall Length D 2.67 2.90 3.05 Foot Length L 0.13 0.50 0.60 Foot Angle φ 0° – 10° Lead Thickness c 0.08 – 0.20 Lead Width b 0.30 – 0.54 Notes: 1. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.25 mm per side. 2. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. Microchip Technology Drawing C04-104B DS21384D-page 8 © 2007 Microchip Technology Inc. TC1278/TC1279 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. -XX X XX Device Reset VCC Threshold Temperature Range Package Device TC1278: TC1279: 3-Pin Reset Monitor for 5V Systems 3-Pin Reset Monitor for 5V Systems Reset VCC Threshold: 5 10 15 = 4.625V = 4.375V = 4.125V Temperature Range E = -40°C to +85°C Package NBTR = Plastic Small Outline Transistor, (SOT23), 3-lead (Tape and Reel) © 2007 Microchip Technology Inc. Examples: a) b) c) TC1278-5ENBTR: 4.625 Reset TC1278-10ENBTR: 4.375 Reset TC1278-15ENBTR: 4.125 Reset a) b) c) TC1279-5ENBTR: 4.625 Reset TC1279-10ENBTR: 4.375 Reset TC1279-15ENBTR: 4.125 Reset DS21384D-page 9 TC1278/TC1279 NOTES: DS21384D-page 10 © 2007 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. • Microchip is willing to work with the customer who is concerned about the integrity of their code. • Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.” Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC, and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Linear Active Thermistor, Migratable Memory, MXDEV, MXLAB, PS logo, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, rfPICDEM, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2007, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified. © 2007 Microchip Technology Inc. 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