a Microprocessor Supervisory Circuit in 3-Pin SOT-23 ADM809/ADM810 FUNCTIONAL BLOCK DIAGRAM FEATURES Superior Upgrade for MAX809/MAX810 Specified Over Temperature Low Power Consumption (17 mA) Precision Voltage Monitor: +3 V, +3.3 V, +5 V Options Reset Assertion Down to 1 V VCC 140 ms min Power-On Reset Logic Low RESET Output (ADM809) Logic High RESET Output (ADM810) ADM809/ADM810 VCC RESET GENERATOR 240ms VREF RESET (RESET) GND APPLICATIONS Microprocessor Systems Computers Controllers Intelligent Instruments Automotive Systems GENERAL DESCRIPTION The ADM809/ADM810 supervisory circuits monitor the power supply voltage in microprocessor systems. They provide a reset output during power-up, power-down and brownout conditions. On power-up, an internal timer holds reset asserted for 240 ms. This holds the microprocessor in a reset state until conditions have stabilized. The RESET output remains operational with VCC as low as 1 V. The ADM809 provides an active low reset signal (RESET) while the ADM810 provides an active high signal (RESET) output. Six reset threshold voltage options are available suitable for monitoring a variety of supply voltages. Refer to Table I. VCC VCC ADM809 GND VCC RESET RESET INPUT µP SYSTEM GND The reset comparator features built-in glitch immunity, making it immune to fast transients on VCC. The ADM809/ADM810 consumes only 17 µA, making it suitable for low power portable equipment. It is packaged in a 3-pin SOT-23 package. Figure 1. Typical Operating Circuit REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements 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 Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 World Wide Web Site: http://www.analog.com Fax: 617/326-8703 © Analog Devices, Inc., 1997 (VCC = Full Operating Range, TA = TMIN to TMAX, VCC typ = 5 V for L/M/J, 3.3 V ADM809/ADM810–SPECIFICATIONS for T/S, 3 V for R Models unless otherwise noted.) Parameter VCC Operating Voltage Range Min 4.56 4.5 4.40 4.31 4.25 4.16 3.93 3.89 3.80 3.04 3.00 2.92 2.89 2.85 2.78 2.59 2.55 2.50 Reset Threshold Temperature Coefficient VCC to Reset Delay Reset Active Timeout Period 140 100 Test Conditions/Comments 24 17 5.5 5.5 60 50 100 100 V V µA µA µA µA TA = 0°C to +70°C TA = –40°C to +105°C VCC < 5.5 V, ADM8_L/M, TA = –40°C to +85°C VCC < 3.6 V, ADM8_R/S/T, TA = –40°C to +85°C VCC < 5.5 V, ADM8_L/M, TA = +85°C to +105°C VCC < 3.6 V, ADM8_R/S/T, TA = +85°C to +105°C 4.70 4.75 4.86 4.45 4.5 4.56 4.06 4.10 4.20 3.11 3.15 3.23 2.96 3.00 3.08 2.66 2.70 2.76 V V V V V V V V V V V V V V V V V V TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C TA = +25°C TA = –40°C to +85°C TA = +85°C to +105°C ppm/°C µs VCC = VTH to (VTH –100 mV) 560 840 ms ms TA = –40°C to +85°C TA = +85°C to +105°C 0.3 0.4 0.3 V V V VCC = VTH min, ISINK = 1.2 mA, ADM809R/S/T VCC = VTH min, ISINK = 3.2 mA, ADM809L/M VCC >1.0 V, ISINK = 50 µA V V VCC > VTH max, ISOURCE = 500 µA, ADM809R/S/T VCC > VTH max, ISOURCE = 800 µA, ADM809L/M V V VCC = VTH min, ISINK = 1.2 mA, ADM810R/S/T VCC = VTH min, ISINK = 3.2 mA, ADM810L/M V 1.8 V < VCC < VTH min, ISOURCE = 150 µA 4.63 4.38 4.00 3.08 2.93 2.63 240 0.8 VCC VCC–1.5 RESET Output Voltage Low (ADM810) RESET Output Voltage High (ADM810) Units 30 20 RESET Output Voltage Low (ADM809) RESET Output Voltage High (ADM809) Max 1.0 1.2 Supply Current RESET THRESHOLD Reset Voltage Threshold ADM8_L ADM8_L ADM8_L ADM8_M ADM8_M ADM8_M ADM8_␣ J ADM8_ J ADM8_ J ADM8_T ADM8_T ADM8_T ADM8_S ADM8_S ADM8_S ADM8_R ADM8_R ADM8_R Typ 0.3 0.4 0.8 VCC ABSOLUTE MAXIMUM RATINGS* (TA = +25°C unless otherwise noted) VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V RESET, RESET . . . . . . . . . . . . . . . . . . –0.3 V to Vcc + 0.5 V Input Current VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA Output Current RESET, RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA Rate of Rise, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 V/µs Power Dissipation, RT-3 SOT-23 . . . . . . . . . . . . . . . . 320 mW Derate by 4 mW/°C above +70°C θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . . . . 333°C/W Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . +300°C Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . +215°C Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C *Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum ratings for extended periods of time may affect device reliability. CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the ADM809/ADM810 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. –2– WARNING! ESD SENSITIVE DEVICE REV. 0 ADM809/ADM810 PIN FUNCTION DESCRIPTION Pin Mnemonic Function 1 GND 0 V. Ground reference for all signals. 2 RESET (ADM809) Active Low Logic Output. RESET remains low while VCC is below the reset threshold, and remains low for 240 ms (typ) after VCC rises above the reset threshold 2 3 VREF VCC RESET Table I. Reset Threshold Options GND 1 RESET, RESET 2 t1 Figure 2. Power Fail Reset Timing PIN CONFIGURATION TOP VIEW (Not to Scale) VREF t1 = RESET TIME = 240ms TYP. VREF = RESET VOLTAGE THRESHOLD Supply voltage being monitored. ADM809/ ADM810 VREF t1 RESET (ADM810) Active High Logic Output. RESET remains high while VCC is below the reset threshold, and remains high for 240 ms (typ) after VCC rises above the reset threshold. VCC VREF 3 VCC RESET, RESET Model RESET Threshold ADM809LART ADM809MART ADM809JART ADM809TART ADM809SART ADM809RART 4.63 V 4.38 V 4.00 V 3.08 V 2.93 V 2.63 V ADM810LART ADM810MART ADM810JART ADM810TART ADM810SART ADM810RART 4.63 V 4.38 V 4.00 V 3.08 V 2.93 V 2.63 V ORDERING GUIDE Model* Reset Threshold Temperature Range Brand Information Quantity ADM809LART-REEL ADM809LART-REEL-7 ADM809MART-REEL ADM809MART-REEL-7 ADM809JART-REEL ADM809JART-REEL-7 ADM809TART-REEL ADM809TART-REEL-7 ADM809SART-REEL ADM809SART-REEL-7 ADM809RART-REEL ADM809RART-REEL-7 ADM810LART-REEL ADM810LART-REEL-7 ADM810MART-REEL ADM810MART-REEL-7 ADM810JART-REEL ADM810JART-REEL-7 ADM810TART-REEL ADM810TART-REEL-7 ADM810SART-REEL ADM810SART-REEL-7 ADM810RART-REEL ADM810RART-REEL-7 4.63 V 4.63 V 4.38 V 4.38 V 4.00 V 4.00 V 3.08 V 3.08 V 2.93 V 2.93 V 2.63 V 2.63 V 4.63 V 4.63 V 4.38 V 4.38 V 4.00 V 4.00 V 3.08 V 3.08 V 2.93 V 2.93 V 2.63 V 2.63 V –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C –40°C to +105°C 9LXX 9LXX 9MXX 9MXX 9JXX 9JXX 9TXX 9TXX 9SXX 9SXX 9RXX 9RXX ALXX ALXX AMXX AMXX AJXX AJXX ATXX ATXX ASXX ASXX ARXX ARXX 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K 10K 3K *Only available in Reels. REV. 0 –3– ADM809/ADM810—Typical Performance Characteristics 200 30 25 VOD = 10mV VOD = 10mV 140 140 VCC = 3V VOD = VTH – VCC 160 160 20 120 120 100 VOD = 20mV 100 15 80 VOD = 20mV 80 10 60 60 VCC = 1V –20 0 20 40 60 TEMPERATURE – C 40 VOD = 100mV 40 5 0 –40 180 VOD = VTH – VCC 180 VCC = 5V 80 85 Figure 3. Supply Current vs. Temperature (ADM8_L/M/R/S/T) (No Load) VOD = 100mV 20 20 0 –40 VOD = 200mV –20 0 20 40 60 TEMPERATURE – C Figure 4. Power-Down RESET Delay vs. Temperature ADM8_L/M VOD = 200mV 0 –40 80 85 –20 0 20 40 60 TEMPERATURE – C 80 85 Figure 5. Power-Down RESET Delay vs. Temperature ADM8_T/S/R 1.002 240 239.5 SUPPLY VOLTAGE 5VPK TO PK 1.0015 239 238.5 1.001 T 238 1.0005 237.5 RESET OUTPUT VOLTAGE 1 237 ADM809T ADM809R 1.0 236.5 236 2 0.9995 T 235.5 235 –40 –20 0 20 40 60 TEMPERATURE – C 80 85 Figure 6. Power-Down RESET Delay vs. Temperature ADM8_R 0.999 –40 –20 0 20 40 60 TEMPERATURE – C 80 85 Figure 7. Normalized RESET Voltage Threshold vs. Temperature CH1 2.00V CH2 2.00V M 200ms CH1 2.00V Figure 8. RESET Output Voltage vs. Supply Voltage 400 350 300 250 200 150 ADM8_L/M 100 ADM8_R/S/T 50 0 1 10 100 1000 RESET COMPARATOR OVERDRIVE, VTH – VCC (mV) Figure 9. Maximum Transient Duration Without Causing a RESET Pulse vs. RESET Comparator Overdrive –4– REV. 0 ADM809/ADM810 INTERFACING TO OTHER DEVICES OUTPUT The ADM809/ADM810 Series is designed to integrate with as many devices as possible and therefore has a standard output dependant on VCC. This enables the part to be used in both 3 V and 5 V or any nominal voltage within the minimum and maximum specifications for VCC. Because of this design approach, interfacing this device to other devices is simplified. ENSURING A VALID RESET OUTPUT DOWN TO V CC = 0 V When VCC falls below 0.8 V, ADM809’s RESET no longer sinks current. A high impedance CMOS logic input connected to RESET may, therefore, drift to undetermined logic levels. To eliminate this problem a 100 kΩ resistor should be connected from RESET to ground. THE BENEFITS OF A VERY ACCURATE RESET THRESHOLD In other microprocessor supervisory circuits, tolerances in supply voltages lead to an overall increase in RESET tolerance levels due to the deterioration of the microprocessor RESET circuit’s power supply. The possibility of a malfunction during a power failure is greatly reduced because the ADM809 and ADM810 series can operate effectively even when there are large degradations of the supply voltages. Another advantage of the ADM809 and ADM810 series is its very accurate internal voltage reference circuit. These benefits combine to produce an exceptionally reliable Voltage Monitor Circuit. INTERFACING TO MICROPROCESSORS WITH MULTIPLE INTERRUPTS In a number of cases it is necessary to interface many interrupts from different devices (i.e., thermal, attitude and velocity sensors). The ADM809 and ADM810 can easily be integrated into existing interrupt-handling circuits (Figure 11) or used as a stand-alone device. VCC VCC ADM809 RESET PRIORITY ENCODER 74LS147 4 LINE BCD TO µP VCC VCC GND ADM809 RESET OTHER SENSING DEVICES Figure 10. Ensuring a Valid RESET Output Down to VCC = 0 V GND Figure 11. Interfacing to µ Ps with Multiple Interrupts REV. 0 –5– ADM809/ADM810 OUTLINE DIMENSIONS Dimensions shown in inches and (mm). Surface Mount Package RT-3 0.0550 (1.397) 0.0470 (1.194) 3 1 2 C3047–12–4/97 0.1200 (3.048) 0.1102 (2.799) 0.1040 (2.642) 0.0827 (2.101) PIN 1 0.0236 (0.599) 0.0177 (0.450) 0.0413 (1.049) 0.0374 (0.950) 0.0807 (2.050) 0.0701 (1.781) SEATING PLANE 0.0210 (0.533) 0.0146 (0.371) 0.0059 (0.150) 0.0034 (0.086) 0.0100 (0.254) 0.027 (0.686) REF 0.0050 (0.127) PRINTED IN U.S.A. 0.0040 (0.102) 0.0005 (0.013) 0.0440 (1.118) 0.0320 (0.813) –6– REV. 0