SGM706 Low-Cost, Microprocessor Supervisory Circuit

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1 GENERAL DESCRIPTION The microprocessor supervisory circuit reduces the complexity and number of components required to monitor power supply and monitor microprocessor activity. It significantly improves system reliability and accuracy compared to separate ICs or discrete components. The provides power supply monitoring circuitry that generates a reset output during power-up, power-down and brownout conditions. The reset output remains operational with as low as 1V. Independent watchdog monitoring circuitry is also provided. This is activated if the watchdog input has not been toggled within 1.6 seconds. In addition, there is a 1.25V threshold detector for power-fail warning, low-battery detection, or monitoring an additional power supply. An active-low manual-reset input ( ) is also included. The is available in Green SOIC-8 package. The -S is available in both Green SOIC-8 and MSOP-8 packages. They operate over an ambient temperature range of -40 to +85. TYPICAL APPLICATION FEATURES Precision Supply-Voltage Monitor 4.65V for -L 4.40V for -M 4.0V for -J 3.08V for -T 2.93V for -S 2.63V for -R Guaranteed Valid at = 1V 200ms Reset Pulse Width Debounced TTL/CMOS-Compatible Manual-Reset Input Independent Watchdog Timer (1.6sec) Timeout Voltage Monitor for Power-Fail or Low-Battery Warning -40 to +85 Operating Temperature Range is Available in Green SOIC-8 Package -S is Available in both Green SOIC-8 and MSOP-8 Packages APPLICATIONS Computers Controllers Intelligent Instruments Automotive Systems Critical μp Power Monitoring UNREGULATED DC +5V DC LINEAR REGULATOR MICROPROCESSOR PUSHBUTTON SWITCH WDI WDO I/O LINE NMI INTERRUPT REV. B

2 PACKAGE/ORDERING INFORMATION MODEL THRESHOLD (V) PACKAGE DESCRIPTION ORDERING NUMBER PACKAGE MARKING PACKAGE OPTION 4.65 SOIC-8 -LYS8G/TR -LYS SOIC-8 -MYS8G/TR -MYS8 4.0 SOIC-8 -JYS8G/TR -JYS SOIC-8 -TYS8G/TR -TYS SOIC-8 -SYS8G/TR -SYS MSOP-8 -SYMS8G/TR S YMS SOIC-8 -RYS8G/TR -RYS8 NOTE: = Date Code and Vendor Code. Green (RoHS & HSF): defines "Green" to mean Pb-Free (RoHS compatible) and free of halogen substances. If you have additional comments or questions, please contact your SGMICRO representative directly. ABSOLUTE MAXIMUM RATINGS (Typical values are at T A = +25, unless otherwise noted.) Terminal Voltage (with respect to ) V to 6.0V All Other Inputs V to ( + 0.3V) Input Current,... 20mA... 20mA Output Current, (all outputs)... 20mA Operating Temperature Range to +85 Junction Temperature Storage Temperature to +150 Lead Temperature (Soldering, 10s) ESD Susceptibility HBM V MM V ESD SENSITIVITY CAUTION This integrated circuit can be damaged by ESD if you don t pay attention to ESD protection. SGMICRO recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. DISCLAIMER reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. OVERSTRESS CAUTION Stresses beyond those listed may cause permanent damage to the device. Functional operation of the device at these or any other conditions beyond those indicated in the operational section of the specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. 2

3 PIN CONFIGURATIONS -L/M/J/T/S/R (TOP VIEW) -S (TOP VIEW) 1 8 WDO 1 8 WDI 2 3 -L/M/J/T/S/R 7 6 WDI WDO 2 3 -S SOIC-8 MSOP-8 PIN DESCRIPTION PIN SOIC-8 MSOP-8 NAME FUNCTION Manual-Reset Input triggers a reset pulse when pulled below 0.8V. This active-low input 1 3 has an internal 250μA ( = +5V) pull-up current. It can be driven from a TTL or CMOS logic line as well as shorted to ground with a switch. 2 4 Power Supply Voltage that is monitored V Ground Reference for all signals WDI WDO Power-Fail Voltage Monitor Input. When is less than 1.25V, goes low. Connect to or when not used. Power-Fail Output goes low and sinks current when is less than 1.25V; otherwise stays high. Watchdog Input. If WDI remains high or low for 1.6sec, the internal watchdog timer runs out and WDO goes low (BLOCK DIAGRAM). Floating WDI or connecting WDI to a high-impedance three-state buffer disables the watchdog feature. The internal watchdog timer clears whenever reset is asserted, WDI is three-stated, or WDI sees a rising or falling edge. Active-Low Reset Output pulses low for 200ms when triggered, and stays low whenever is below the reset threshold (4.65V for -L, 4.4V for -M, 4.0V for -J, 3.08V for -T and 2.93V for -S, 2.63V for -R). It remains low for 200ms after rises above the reset threshold or goes from low to high. A watchdog timeout will not trigger unless WDO is connected to. Watchdog Output pulls low when the internal watchdog timer finishes its 1.6sec count and does not go high again until the watchdog is cleared. WDO also goes low during low-line conditions. Whenever is below the reset threshold, WDO stays low; however, unlike, WDO does not have a minimum pulse width. As soon as rises above the reset threshold, WDO goes high with no delay. 3

4 ELECTRICAL CHARACTERISTICS ( = 4.75V to 5.5V for -L; = 4.5V to 5.5V for -M; = 4.07V to 5.5V for -J; = 3.14V to 5.5V for -T; = 2.95V to 5.5V for -S; = 2.68V to 5.5V for -R; T A = -40 C to +85 C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS Operating Voltage Range () V Supply Current (I SUPPLY) μa Reset Threshold (V RT) Reset Threshold Hysteresis -L M J T S (SOIC-8) S (MSOP-8) R L, -M 40 -J 34 -T, -S 25 -R 22 Reset Pulse Width (t RS) ms Output Voltage I SOURCE = 800μA 0.7 I SINK = 3.2mA 0.4 = 1V, I SINK = 50μA 0.3 Watchdog Timeout Period (t WD) sec WDI Pulse Width (t WP) V IL = 0.4V, V IH = 70 ns WDI Input Threshold WDI Input Current WDO Output Voltage Low = 5V 0.8 High = 5V 3.5 Low V RST(MAX) < < 3.6V 0.8 High V RST(MAX) < < 3.6V 0.7 WDI = WDI = 0V I SOURCE = 800μA 0.7 I SINK = 1.2mA 0.4 Pull-Up Current = 0V μa Pulse Width (t ) 250 ns Input Threshold Low T A = +25 High 2 to Reset Out Delay (t MD) 350 ns Input Threshold = 5V V Input Current 0.2 na Output Voltage I SOURCE = 800μA 0.7 I SINK = 3.2mA V mv V V μa V V V 4

5 FUNCTIONAL BLOCK DIAGRAM WDI 6 WATCHDOG TRANSITION DETECTOR WATCHDOG TIMER 8 WDO 1 250μA TIMEBASE FOR AND WATCHDOG 2 + _ GENERATOR V for -L* 4 + _ V SOIC-8 Package * 4.65V for -L 4.40V for -M 4.0V for -J 3.08V for -T 2.93V for -S 2.63V for -R 3 5

6 TYPICAL PERFORMANCE CHARACTERISTICS 2kΩ 330pF 10kΩ 30pF +5V pF +1.25V 1kΩ + +5V 1kΩ V 30pF 6

7 TYPICAL PERFORMANCE CHARACTERISTICS (continued) 7

8 APPLICATION NOTES Ensuring a Valid Output Down to = 0V When falls below 1V, the output no longer sinks current-it becomes an open circuit. High-impedance CMOS logic inputs can drift to undetermined voltages if left undriven. If a pull-down resistor is added to the pin as shown in Figure 1, any stray charge or leakage currents will be drained to ground, holding low. Resistor value (R1) is not critical. It should be about 100kΩ, large enough not to load and small enough to pull to ground. R1 Monitoring a Negative Voltage The power-fail comparator can also monitor a negative supply rail (Figure 3). When the negative rail is good (a negative voltage of large magnitude), is low, and when the negative rail is degraded (a negative voltage of lesser magnitude), is high. By adding the resistors and transistor as shown, a high triggers reset. As long as remains high, the will keep reset asserted ( = low, = high). Note that this circuit s accuracy depends on the threshold tolerance, the line, and the resistors. +5V R1 R2 100kΩ TO μp 100kΩ 2N3904 V- Figure 1. Valid to Ground Circuit Monitoring Voltages Other Than the Unregulated DC Input Monitor voltages other than the unregulated DC by connecting a voltage divider to and adjusting the ratio appropriately. If required, add hysteresis by connecting a resistor (with a value approximately 10 times the sum of the two resistors in the potential divider network) between and. A capacitor between and will reduce the power-fail circuit s sensitivity to high-frequency noise on the line being monitored. can be asserted on other voltages in addition to the +5V line. Connect to to initiate a pulse when drops below 1.25V. Figure 2 shows the configured to assert when the +5V supply falls below the reset threshold, or when the +12V supply falls below approximately 11V. +12V +5V +5V 0V +5V 0V V- V TRIP 0V V TRIP = V TRIP < 0 R1 R2 Figure 3. Monitoring a Negative Voltage Interfacing to μps with Bidirectional Reset Pins μps with bidirectional reset pins, such as the Motorola 68HC11 series, can contend with the output. If, for example, the output is driven high and the Microprocessor wants to pull it low, indeterminate logic levels may result. To correct this, connect a 4.7kΩ resistor between the output and the μp reset I/O, as in Figure 4. Buffer the output to other system components. BUFFRED TO OTHER SYSTEM COMPONENTS 1MΩ 1% 130kΩ 1% TO μp VCC 4.7kΩ VCC Microprocessor Figure 2. Monitoring Both +5V and +12V Figure 4. Interfacing to Microprocessors with Bidirectional Reset I/O 8

9 REVISION HISTORY NOTE: Page numbers for previous revisions may differ from page numbers in the current version. REV.A.4 to REV.B Changed Electrical Characteristics section... 4 AUGUST 2017 REV.A.3 to REV.A.4 -S Added MSOP-8 Package... All MARCH 2017 REV.A.2 to REV.A.3 Changed Packing Option... 2 JANUARY 2013 REV.A.1 to REV.A.2 Added Recommended Land Pattern Information Added Tape and Reel Information... 11, 12 MAY 2011 REV.A to REV.A.1 Updated Package Description... All Changes from Original (APRIL 2010) to REV.A Changed from product preview to production data... All 9

10 PACKAGE INFORMATION PACKAGE OUTLINE DIMENSIONS SOIC-8 D e E1 E 5.2 b 1.27 RECOMMENDED LAND PATTERN (Unit: mm) L A A1 θ c A2 Symbol Dimensions In Millimeters Dimensions In Inches MIN MAX MIN MAX A A A b c D E E e 1.27 BSC BSC L θ TX

11 PACKAGE INFORMATION PACKAGE OUTLINE DIMENSIONS MSOP-8 b E1 E 4.8 e RECOMMENDED LAND PATTERN (Unit: mm) D L A A1 A2 c θ Symbol Dimensions In Millimeters Dimensions In Inches MIN MAX MIN MAX A A A b c D E E e BSC BSC L θ TX

12 PACKAGE INFORMATION TAPE AND REEL INFORMATION REEL DIMENSIONS TAPE DIMENSIONS P2 P0 W Q1 Q2 Q1 Q2 Q1 Q2 B0 Q3 Q4 Q3 Q4 Q3 Q4 Reel Diameter P1 A0 K0 Reel Width (W1) DIRECTION OF FEED NOTE: The picture is only for reference. Please make the object as the standard. KEY PARAMETER LIST OF TAPE AND REEL Package Type Reel Diameter Reel Width W1 A0 B0 K0 P0 P1 P2 W Pin1 Quadrant SOIC Q1 MSOP Q1 DD0001 TX

13 PACKAGE INFORMATION CARTON BOX DIMENSIONS NOTE: The picture is only for reference. Please make the object as the standard. KEY PARAMETER LIST OF CARTON BOX Reel Type Length Width Height Pizza/Carton DD0002 TX