ASM161 / ASM162 October 2003 rev 1.0 µP Supervisory Circuit General Description Key Features The ASM161 and ASM162 are cost effective, low power • • • • • • supervisory circuits that monitor power supplies in microprocessor, microcontroller and digital systems. If the power supply drops below the reset threshold level, a reset is asserted and remains asserted for atleast 800ms after VCC has risen above the reset threshold. An improved manual reset architecture gives the system designer additional flexibility. • The debounced manual reset input is negative edge triggered. • The reset pulse period generated by a MR transition is a minimum of 800 ms and a maximum of 2 sec duration. In addition, The MR input signal is blocked for an additional 49µS minimum after the reset pulse ends. During the MR disable period, the microcontroller is guaranteed a time period free of additional manual reset signals. During this period DRAM contents can be refreshed or other critical system tasks undertaken. Low power consumption makes the ASM161/162 ideal for use in portable and battery operated equipments. With 3V supplies power consumption is 8µW typically and 30µW maximum. The ASM161 has an open-drain, active-LOW RESET output and requires an external pull-up resistor. The ASM162 has an active HIGH RESET output. • • • Edge triggered manual reset input single pulse output 49µS minimum MR disable period after reset CMOS/TTL logic or switch interface Debounced input Low supply current extends battery life • 6µA / 15µA typ/max at 5.5V • 4.5µA / 10µA typ/max at 3.6V Long reset period • 0.8 sec minimum, 2 sec maximum Two reset polarity options • ASM161: Active LOW, open-drain • ASM162: Active HIGH Pinout matches the AS811/812 Small 4-Pin SOT-143 package Two temperature ranges: 00 to 700c and -400c to +850c Applications • • • • • • • PDAs Appliances Computers and embedded controllers Wireless communication systems Battery operated and intelligent instruments Automotive systems Safety systems Typical Operating Circuit The ASM161/162 are offered in compact 4-pin SOT-143 packages. No external components are required to trim threshold voltage for monitoring different supply voltages. With six different factory set, reset, threshold ranges from 2.63V to VCC 4.63V, the ASM161/162 are suitable for monitoring 5V, 3.6V and 3.0V supplies. The ASM161/162 are available in ASM161 (ASM162) RESET (RESET) Reset Threshold Part Suffix Voltage (V) L 4.63 M 4.38 J 4.00 T 3.08 S 2.93 R 2.63 VCC VCC temperature ranges 00 to 700c and -400c to +850c. 20k for ASM161 only RESET (RESET) µP MR GND GND Alliance Semiconductor 2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com Notice: The information in this document is subject to change without notice ASM161 / ASM162 October 2003 rev 1.0 Block Diagram 4 Reset Circuit + 3 VCC ASM161/162 - Voltage Divider * Edge Trigger Bandgap Reference 4 2 ASM161 RESET (ASM161) RESET (ASM162) 2 MR Debounce Reset Circuit ~ ~ MR RPU ~ VCC * Non-retriggerable, edge triggered manual reset 1 GND Pin Configuration SOT-143 GND SOT-143 4 1 VCC GND 1 ASM161 RESET VCC 3 MR ASM162 3 2 4 MR RESET 2 RESET is open drain Pin Description Pin # Pin Name ASM161 ASM162 1 1 GND Description Ground. Active-LOW, open-drain reset output. RESET remains LOW while VCC is below the 2 - RESET reset threshold and for 800ms minimum after VCC rises above the reset threshold. An external pull-up resistor is needed. - 2 RESET Active HIGH reset output. RESET remains HIGH while VCC is below the reset threshold and for 800ms after VCC rises above the reset threshold. 3 3 MR Manual reset input. A negative going edge transition on MR asserts reset. Reset remains asserted for one reset time-out period (800 ms min). This active-LOW input has an internal pull-up resistor. It can be driven from a TTL or CMOS logic line or shorted to ground with a switch. Leave open if unused. 4 4 VCC Power supply input voltage. µP Supervisory Circuit Notice: The information in this document is subject to change without notice 2 of 9 ASM161 / ASM162 October 2003 rev 1.0 Detailed Descriptions The MR pin must be taken HIGH and LOW again after the tMRD period has been completed to initiate another reset The reset function ensures the microprocessor is properly pulse. reset and powers up into a known condition after a power The manual reset input has an internal 20kΩ pull-up resistor. failure. MR can be left open if not used. tMD Reset Timing A reset is generated whenever the supply voltage is below the threshold level (VCC < VTH). The reset duration is at least MR Triggering Pulse 800ms after VCC has risen above the reset threshold and is guaranteed to be no more than 2 seconds. The rest signal tMRD remains active as long as the monitored supply voltage is Reset Time-Out below the internal threshold voltage. RESET *Second and following edges ignored The ASM161 has an open-drain, active LOW RESET output Figure 1: Manual Reset Timing (which is guaranteed to be in the correct state for VCC down to 1.1 V). The ASM161 uses an external pull-up resistor. Ready for next MR MR input is blocked *........ Output leakage current is under 1µA. A high resistance value Application Information can be used to minimize current drain. Glitch Resistance The ASM161/162 are relatively immune to short duration The ASM162 generates an active-HIGH RESET output. negative-going VCC transients/glitches. A VCC transient that goes 100mV below the reset threshold and lasts 20s or less will not typically cause a reset pulse. Part Number Reset Polarity ASM161 LOW (use external pull-up resistor) ASM162 HIGH VCC 100KΩ ASM162 Power Supply RESET MR Manual Reset The ASM161/162 have a unique manual reset circuit. A GND negative going edge transition on MR initiates the reset. A manual reset generates a single reset pulse of fixed length. The output-reset pulse remains asserted for the Reset Active Figure 2: RESET valid with VCC under 1.1V Time-Out Period tRP and then clears. Once the reset pulse is Valid Reset with VCC under 1.1V completed, the MR input remains disabled for at least 49µS To ensure that logic inputs connected to the ASM162 RESET but not more than 122µS. This period is specified as tMRD. pin are in a known state when VCC is under 1.1V, a 100kΩ pull-down resistor at RESET is needed. The value is not During the MR disabled period, the microcontroller is critical. guaranteed a time period free of new manual reset signals. This period can be used to refresh critical DRAM contents or This scheme does not work with the open-drain outputs of other system tasks. ASM161. µP Supervisory Circuit Notice: The information in this document is subject to change without notice 3 of 9 ASM161 / ASM162 October 2003 rev 1.0 Absolute Maximum Ratings Parameter Min Max Unit VCC -0.3 6.0 V RESET, RESET and MR -0.3 VCC + 0.3 V 20 mA Rate of Rise at VCC 100 V/µs Power Dissipation (TA = 70°C) 320 mW Pin Terminal Voltage with respect to Ground Input Current at VCC and MR Operating Temperature Range -40 85 °C Storage Temperature Range -65 160 °C 300 °C Lead Temperature (soldering, 10 sec) Note: These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. µP Supervisory Circuit Notice: The information in this document is subject to change without notice 4 of 9 ASM161 / ASM162 October 2003 rev 1.0 Electrical Characteristics Unless otherwise noted, VCC is over the full range and TA = 00 to 700c for ASM161/162 X C and TA = -400c to +850c for ASM161/ 162 X E devices. Typical values at TA = 250c, VCC = 5V for L/M/J devices, VCC = 3.3V for T/S devices and VCC = 3V for R devices Parameter Input Voltage (VCC) Range Supply Current (Unloaded) Symbol VCC ICC Conditions TA = 0°C to 70°C VCC < 5.5V, TA = -40°C to +85°C L/M/J TA = 0°C to 70°C, VCC < 3.6V, TA = -40°C to +85°C R/S/T L Devices TA = 25°C 4.56 Note 1 4.50 TA = 25°C 4.31 Note 1 4.25 TA = 25°C 3.93 Note 1 3.89 TA = 25°C 3.04 Note 1 3.00 TA = 25°C 2.89 Note 1 2.85 TA = 25°C 2.59 Note 1 2.55 J devices VTH T devices S devices R devices Reset Threshold Temp Coefficient Reset Pulse Width MR Minimum Pulse Width 6 VCC = VTH to (VTH -100mV) tRPW TA = 0°C to 70°C 800 TA = -40°C to 85°C 560 tMR Unit 5.5 V 15 4.5 10 4.63 4.70 4.75 4.38 4.45 4.50 4.00 4.06 4.10 3.08 V 3.11 3.15 2.93 2.96 3.00 2.63 2.66 2.70 30 ppm/ °C 20 µS 1400 2000 ms 2240 10 MR Glitch Immunity MR to RESET Propagation Delay Max µA TCVTH VCC to reset delay Typ 1.1 TA = 0°C to 70°C, M devices Reset Threshold Min tMD µP Supervisory Circuit Notice: The information in this document is subject to change without notice µS 100 ns 0.5 µs 5 of 9 ASM161 / ASM162 October 2003 rev 1.0 Parameter Symbol VIH VIL MR Input Threshold VCC > VTH(MAX), L/M/J devices VIH VIL MR Delay to MR Retrigger Conditions tMRD Min 0.7VCC TA = 0°C to 70°C VCC = VTH min., ISINK = 3.2mA, VOH VDRAIN < 6.0V, 0°C < TA < 70°C 1 VCC = VTH min., ISINK = 1.2mA, 0.3 ASM162 R/S/T V µA V VCC = VTH min., ISINK = 3.2mA, 1.8<VCC<VTHmin., ISOURCE = 150 µA KΩ 0.3 0.4 ASM162 L/M/J HIGH RESET Output Voltage (ASM162) 30 0.4 ASM161 L/M/J VOL 20 0.3 VCC > 1.1, ISINK = 50µA Low RESET output voltage (ASM162) 122 85 ASM161 R/S/T ILKG 85 V µS TA = -40°C to 85°C VCC = VTH min., ISINK = 1.2mA, RESET Output Leakage Current (ASM161) V V 0.25VCC 49 Unit V 0.8 10 VOL Max 2.3 VCC > VTH(MAX), R/S/T devices MR pull-up resistance Low RESET output voltage (ASM161) Typ 0.8VCC V Notes: 1. Over operating temperature range. µP Supervisory Circuit Notice: The information in this document is subject to change without notice 6 of 9 ASM161 / ASM162 October 2003 rev 1.0 Package Dimensions Plastic SOT - 143 (4Pin) e1 B Inches E B1 Min H e Max A 0.031 0.047 0.787 1.194 A1 0.001 0.005 0.025 0.127 B 0.014 0.022 0.356 0.559 B1 0.030 0.038 0.762 0.965 C 0.0034 0.006 0.086 0.152 D 0.105 0.120 2.667 3.048 E 0.047 0.055 1.194 1.397 e 0.070 0.080 1.778 2.032 e1 0.071 0.079 1.803 2.007 H 0.082 0.098 2.083 2.489 L 0.004 0.012 0.102 0.305 A a = 0° -8° e Min Plastic SOT-143 (4-Pin) D A1 Max Millimeters C L Plastic SOT - 143 (4 pin) µP Supervisory Circuit Notice: The information in this document is subject to change without notice 7 of 9 ASM161 / ASM162 October 2003 rev 1.0 Ordering Information Part Number1 Reset Threshold (V) Temperature Range (°C) Pin-Package Package Marking (XX Lot Code) ASM161LCUS/T 4.63 0 TO 70 4-SOT-143 TAXX ASM161MCUS/T 4.38 0 TO 70 4-SOT-143 TBXX ASM161JCUS/T 4.00 0 TO 70 4-SOT-143 TCXX ASM161TCUS/T 3.08 0 TO 70 4-SOT-143 TDXX ASM161SCUS/T 2.93 0 TO 70 4-SOT-143 TEXX ASM161RCUS/T 2.63 0 TO 70 4-SOT-143 TFXX ASM162LCUS/T 4.63 0 TO 70 4-SOT-143 TGXX ASM162MCUS/T 4.38 0 TO 70 4-SOT-143 THXX ASM162JCUS/T 4.00 0 TO 70 4-SOT-143 TIXX ASM162TCUS/T 3.08 0 TO 70 4-SOT-143 TJXX ASM162SCUS/T 2.93 0 TO 70 4-SOT-143 TKXX ASM162RCUS/T 2.63 0 TO 70 4-SOT-143 TLXX ASM161LEUS/T 4.63 -40 TO 85 4-SOT-143 TMXX ASM161MEUS/T 4.38 -40 TO 85 4-SOT-143 TNXX ASM161JEUS/T 4.00 -40 TO 85 4-SOT-143 TOXX ASM161TEUS/T 3.08 -40 TO 85 4-SOT-143 TPXX ASM161SEUS/T 2.93 -40 TO 85 4-SOT-143 TQXX ASM161REUS/T 2.63 -40 TO 85 4-SOT-143 TRXX ASM162LEUS/T 4.63 -40 TO 85 4-SOT-143 TSXX ASM162MEUS/T 4.38 -40 TO 85 4-SOT-143 TTXX ASM162JEUS/T 4.00 -40 TO 85 4-SOT-143 TUXX ASM162TEUS/T 3.08 -40 TO 85 4-SOT-143 TVXX ASM162SEUS/T 2.93 -40 TO 85 4-SOT-143 TWXX ASM162REUS/T 2.63 -40 TO 85 4-SOT-143 TXXX Notes: 1. Tape and Reel packaging is indicated by the /T designation. µP Supervisory Circuit Notice: The information in this document is subject to change without notice 8 of 9 ASM161 / ASM162 Alliance Semiconductor Corporation 2575, Augustine Drive, Santa Clara, CA 95054 Tel: 408 - 855 - 4900 Fax: 408 - 855 - 4999 www.alsc.com Copyright © Alliance Semiconductor All Rights Reserved Part Number: ASM161 / ASM162 Document Version: 1.0 © Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or registered trademarks of Alliance. All other brand and product names may be the trademarks of their respective companies. Alliance reserves the right to make changes to this document and its products at any time without notice. Alliance assumes no responsibility for any errors that may appear in this document. The data contained herein represents Alliance's best data and/or estimates at the time of issuance. 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