STM1001 Reset Circuit FEATURES SUMMARY ■ ■ ■ ■ ■ ■ ■ PRECISION MONITORING OF 3V, 3.3V, and 5V SUPPLY VOLTAGES OPEN DRAIN RST OUTPUT 140ms RESET PULSE WIDTH (min) LOW SUPPLY CURRENT - 6µA (typ) GUARANTEED RST ASSERTION DOWN TO VCC = 1.0V OPERATING TEMPERATURE: –40°C to 85°C (Industrial Grade) LEAD-FREE, SMALL SOT23 PACKAGE Figure 1. Logic Diagram SOT23-3 (WX) Table 1. Signal Names VCC STM1001 Figure 2. Package RST VSS Ground RST Active-Low RESET Output (Open Drain) VCC Supply Voltage Figure 3. SOT23-3 Connections RST VCC VSS AI09116 1 2 3 VSS AI09117 Rev 5.0 September 2005 1/14 STM1001 TABLE OF CONTENTS FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 1. Figure 2. Table 1. Figure 3. Logic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SOT23-3 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Figure 4. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Figure 5. Hardware Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Reset Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Negative-Going VCC Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 TYPICAL OPERATING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 6. Supply Current vs. Temperature, L/M/R/S/T (no load) . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 7. Power-down Reset Delay vs. Temperature - VOD = VTH – VCC (L/M). . . . . . . . . . . . . . . . 5 Figure 8. Power-down Reset Delay vs. Temperature - VOD = VTH – VCC (R/S/T) . . . . . . . . . . . . . . 6 Figure 9. Power-up trec vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 10.Normalized Reset Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 11.Max Transient Duration NOT Causing Reset Pulse vs. Reset Comparator Overdrive . . . 7 MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 2. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 DC and AC PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 3. Operating and AC Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 12.AC Testing Input/Output Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 4. DC and AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 PACKAGE MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 13.SOT23-3 – 3-lead Small Outline Transistor Package Outline . . . . . . . . . . . . . . . . . . . . . 11 Table 5. SOT23-3 – 3-lead Small Outline Transistor Package Mechanical Data . . . . . . . . . . . . . 11 PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 6. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 7. Marking Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 REVISION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 8. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2/14 STM1001 SUMMARY DESCRIPTION The STM1001 MICROPROCESSOR RESET Circuit is a low-power supervisory device used to monitor power supplies. It performs a single function: asserting a reset signal whenever the VCC supply voltage drops below a preset value and keeping it asserted until VCC has risen above the preset threshold for a minimum period of time (trec). Figure 4. Block Diagram VCC VRST COMPARE trec Generator RST(1) AI09118 Note: 1. Open Drain Figure 5. Hardware Hookup VCC VCC (1) STM1001 MCU (1) RST VSS VCC RESET Input VSS AI09119 Note: 1. RST output requires pull-up resistor. 3/14 STM1001 OPERATION Reset Output The STM1001 MICROPROCESSOR RESET CIRCUIT asserts a reset signal to the MCU whenever VCC goes below the reset threshold (VRST). RST is guaranteed valid down to VCC = 1V (0° to 70°C). During power-up, once VCC exceeds the reset threshold an internal timer keeps RST low for the reset time-out period, trec. After this interval, RST returns high. If VCC drops below the reset threshold, RST goes low. Each time RST is asserted, it stays low for at least the reset time-out period. Any time VCC goes below the reset threshold, the internal timer clears. The reset timer starts when VCC returns above the reset threshold. The active-low reset (RST) is an open drain output. 4/14 Negative-Going VCC Transients The STM1001 is relatively immune to negative-going VCC transients (glitches). Figure 11., page 7 shows typical transient duration versus reset comparator overdrive (for which the STM1001 will NOT generate a reset pulse). The graph was generated using a negative pulse applied to VCC, starting at 0.5V above the actual reset threshold and ending below it by the magnitude indicated (comparator overdrive). The graph indicates the maximum pulse width a negative VCC transient can have without causing a reset pulse. As the magnitude of the transient increases (further below the threshold), the maximum allowable pulse width decreases. Any combination of duration and overdrive which lies under the curve will NOT generate a reset signal. Typically, a VCC transient that goes 100mV below the reset threshold and lasts 20µs or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides additional transient immunity. STM1001 TYPICAL OPERATING CHARACTERISTICS Note: Typical values are at TA = 25°C, VCC = 5V for L/M versions, VCC = 3.3V for T/S versions, and VCC = 3.0V for R versions. Figure 6. Supply Current vs. Temperature, L/M/R/S/T (no load) 8.0 Supply Current (µA) 6.0 1V 3V 3.6V 5.5V 4.0 2.0 0.0 –40 –20 0 20 40 60 80 Temperature (˚C) AI07879 Figure 7. Power-down Reset Delay vs. Temperature - VOD = VTH – VCC (L/M) Power-Down Reset Delay (µs) 140.00 120.00 100.00 VOD = 20mV VOD = 125mV VOD = 200mV 80.00 60.00 40.00 20.00 0.00 –40 –20 0 20 Temperature (˚C) 40 60 80 AI07880 5/14 STM1001 Figure 8. Power-down Reset Delay vs. Temperature - VOD = VTH – VCC (R/S/T) Power-Down Reset Delay (µs) 100.00 80.00 60.00 VOD = 20mV VOD = 125mV VOD = 200mV 40.00 20.00 0.00 –40 –20 0 20 40 60 80 Temperature (˚C) AI07878 Figure 9. Power-up trec vs. Temperature 250.00 Power-up trec (ms) 240.00 230.00 L/M R/S/T 220.00 210.00 200.00 –40 –20 0 20 Temperature (˚C) 40 60 80 AI07881 6/14 STM1001 Figure 10. Normalized Reset Threshold vs. Temperature 1.003 1.002 1.001 Normalized Treshold 1.000 0.999 0.998 L/M R/S/T 0.997 0.996 0.995 0.994 0.993 –40 –20 0 20 40 60 80 Temperature (˚C) AI07882 Figure 11. Max Transient Duration NOT Causing Reset Pulse vs. Reset Comparator Overdrive 700.00 Maximum Transient Duration (µs) 600.00 500.00 400.00 R/S/T L/M 300.00 200.00 100.00 0.00 1 10 100 Reset Comparator Overdrive, VRST – VCC (mV) 1000 AI07883 7/14 STM1001 MAXIMUM RATING Stressing the device above the rating listed in the Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not im- plied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 2. Absolute Maximum Ratings Symbol TSTG TSLD(1) Parameter Value Unit –55 to 150 °C 260 °C –0.3 to VCC +0.3 V Storage Temperature (VCC Off) Lead Solder Temperature for 10 seconds VIO Input or Output Voltage VCC Supply Voltage –0.3 to 7.0 V IO Output Current 20 mA PD Power Dissipation 320 mW Note: 1. Reflow at peak temperature of 255°C to 260°C for < 30 seconds (total thermal budget not to exceed 180°C for between 90 to 150 seconds). DC AND AC PARAMETERS This section summarizes the operating measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC characteristics Tables that follow, are derived from tests performed under the Measurement Conditions summarized in Table 3, Operating and AC Measurement Conditions. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters. Table 3. Operating and AC Measurement Conditions Parameter STM1001 Unit VCC Supply Voltage 1.0 to 5.5 V Ambient Operating Temperature (TA) –40 to 85 °C ≤5 ns Input Pulse Voltages 0.2 to 0.8VCC V Input and Output Timing Ref. Voltages 0.3 to 0.7VCC V Input Rise and Fall Times Figure 12. AC Testing Input/Output Waveforms 0.8VCC 0.2VCC 0.7VCC 0.3VCC AI02568 8/14 STM1001 Table 4. DC and AC Characteristics Sym Alternative VCC Description Test Condition(1) Min TA = –40 to +85°C TA = 0 to +70°C Typ Max Unit 1.2 5.5 V 1.0 5.5 V Operating Voltage VCC Supply Current ICC Open Drain Reset Output Leakage Current ILO VOL VCC < 3.6V 5.5 10 µA VCC < 5.5V 7 15 µA +1 µA STM1001R/S/T only, IOL = 1.2mA VCC = VRST (min) 0.3 V STM1001L/M only, IOL = 3.2mA VCC = VRST (min) 0.4 V IOL = 50µA; VCC > 1.0V 0.3 V 4.70 V 4.75 V 4.45 V 4.50 V 3.11 V 3.15 V 2.96 V 3.00 V 2.66 V 2.70 V VCC > VRST, Reset not asserted –1 RST Output Low Voltage VOL RST Output Low Voltage RESET Thresholds 25°C 4.56 –40 to 85°C 4.50 25°C 4.31 –40 to 85°C 4.25 25°C 3.04 –40 to 85°C 3.00 25°C 2.89 –40 to 85°C 2.85 25°C 2.59 –40 to 85°C 2.55 4.63 STM1001L 4.38 STM1001M VRST Reset Threshold 3.08 STM1001T 2.93 STM1001S 2.63 STM1001R VRST Temperature Coefficient VCC to RST Delay trec RST Pulse Width 45 ppm/ C STM1001L/M 40 µs STM1001R/S/T 20 µs VCC = 3.3V VCC = VRST to (VRST – 100mV) 140 210 280 ms Note: 1. Valid for Ambient Operating Temperature: TA = –40 to 85°C; VCC = 1.2V to 5.5V (except where noted). 2. “Glitches” of 100ns or less typically will not generate a RESET pulse. 9/14 STM1001 PACKAGE MECHANICAL In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a Lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. 10/14 STM1001 Figure 13. SOT23-3 – 3-lead Small Outline Transistor Package Outline E E1 0.15 B M CAB A1 1 e e1 D 0.20 M 3X CAB A2 0.10 C A 3X b C A C θ L1 C L SOT23-3 Note: Drawing is not to scale. Table 5. SOT23-3 – 3-lead Small Outline Transistor Package Mechanical Data mm inches Symbol Typ Min Max A 0.89 A1 Min Max 1.12 0.035 0.044 0.01 0.10 0.001 0.004 A2 0.88 1.02 0.035 0.042 b 0.30 0.50 0.012 0.020 C 0.08 0.20 0.003 0.008 D 2.80 3.04 0.110 0.120 E 2.10 2.64 0.083 0.104 E1 1.20 1.40 0.047 0.055 e 0.89 1.03 0.035 0.041 e1 1.78 2.05 0.070 0.081 L 0.54 Typ 0.021 L1 0.40 0.60 0.016 0.024 Θ 0° 8° 0° 8° N 3 3 11/14 STM1001 PART NUMBERING Table 6. Ordering Information Scheme Example: STM1001 L WX 6 F Device Type STM1001 Reset Threshold Voltage L = VRST = 4.50V to 4.75V M = VRST = 4.25V to 4.50V T = VRST = 3.00V to 3.15V S = VRST = 2.85V to 3.00V R = VRST = 2.55V to 2.70V Package WX = SOT23-3 Temperature Range 6 = –40 to 85°C Shipping Method F = ECOPACK Package, Tape & Reel For other options, or for more information on any aspect of this device, please contact the ST Sales Office nearest you. Table 7. Marking Description Part Number Reset Threshold Output Topside Marking(1) STM1001L 4.63V Open Drain RST 8BAx STM1001M 4.38V Open Drain RST 8BBx STM1001T 3.08V Open Drain RST 8BCx STM1001S 2.93V Open Drain RST 8BDx STM1001R 2.63V Open Drain RST 8BEx Note: 1. Lowercase “x” indicates date code. 12/14 STM1001 REVISION HISTORY Table 8. Document Revision History Date Version Revision Details 09-Dec-03 1.0 First Edition 19-Feb-04 2.0 Part number changed from STM6301 22-Mar-04 2.1 Update DC Characteristics (Table 4) 09-Apr-04 3.0 Device promoted; reformatted; marking updated (Table 7) 19-Nov-04 4.0 Update dimensions (Table 5) 19-Sep-05 5.0 Remove “Valid RST Output Down to VCC...” text 13/14 STM1001 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2005 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 14/14