a Microprocessor Supervisory Circuit ADM809-5S/L FUNCTIONAL BLOCK DIAGRAM FEATURES Specified Over Temperature Low Power Consumption (17 A) Precision Voltage Monitor: 3 V, 5 V Options Reset Assertion Down to 1 V VCC 30 ms min Power-On Reset Logic Low RESET Output ADM809-5S/L VCC RESET GENERATOR 55ms VREF APPLICATIONS Microprocessor Systems Computers Controllers Intelligent Instruments Automotive Systems GENERAL DESCRIPTION The ADM809-5S/L supervisory circuits monitor the power supply voltage in microprocessor systems. It provides a reset output during power-up, power-down and brownout conditions. On power-up, an internal timer holds reset asserted for 55 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 ADM809-5S/L provides an active low reset signal (RESET). The reset comparator features built-in glitch immunity, making it immune to fast transients on VCC. RESET GND VCC VCC VCC ADM809-5S/L RESET GND RESET INPUT P SYSTEM GND Figure 1. Typical Operating Circuit The ADM809-5S/L consumes only 17 µA, making it suitable for low power portable equipment. 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: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 2000 (VCC = Full Operating Range, TA = TMIN to TMAX, VCC typ = 5 V for L, 3.3 V for S ADM809-5S/L–SPECIFICATIONS Models unless otherwise noted.) Parameter VCC Operating Voltage Range Min Typ Max Unit Test Conditions/Comments 1.0 3.3 5.5 V 1.2 3.3 5.5 V 24 17 60 50 100 100 µA µA µA µA TA = 0°C to +150°C with 100 kΩ Pull-Down on Output (Figure 3) TA = –40°C to +150°C with 22 kΩ External Pull-Up on Output (Figure 6) VCC < 5.5 V, ADM8_L, TA = –40°C to +85°C VCC < 3.6 V, ADM8_S, TA = –40°C to +85°C VCC < 5.5 V, ADM8_L, TA = +85°C to +150°C VCC < 3.6 V, ADM8_S, TA = +85°C to +150°C 4.75 4.86 3.00 3.08 V V V V TA = –40°C to +85°C TA = +85°C to +150°C TA = –40°C to +85°C TA = +85°C to +150°C Supply Current RESET THRESHOLD Reset Voltage Threshold ADM809-5L ADM809-5L ADM809-5S ADM809-5S 4.5 4.40 2.85 2.78 Reset Threshold Temperature Coefficient VCC to Reset Delay Reset Active Timeout Period 30 20 30 RESET Output Voltage Low RESET Output Voltage High 0.8 VCC VCC – 1.5 JUNCTION TEMPERATURE –40 55 ppm/°C µs VCC = VTH to (VTH –100 mV) 80 ms TA = –40°C to +150°C 0.3 0.4 0.3 V V V VCC = VTH min, ISINK = 1.2 mA, ADM809-5S VCC = VTH min, ISINK = 3.2 mA, ADM809-5L VCC >1.0 V, ISINK = 50 µA, TA = 0°C to +150°C VCC >1.2 V, ISINK = 50 µA, TA = –40°C to +150°C V V VCC > VTH max, ISOURCE = 500 µA VCC > VTH max, ISOURCE = 800 µA +150 °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 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 Derate by 4 mW/°C above 70°C . . . . . . . . . . . . . . . 320 mW *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 ADM809-5S/L 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 ADM809-5S/L PIN FUNCTION DESCRIPTION Pin Mnemonic Function 1 GND 0 V. Ground reference for all signals. 2 RESET Active Low Logic Output. RESET remains low while VCC is below the reset threshold, and remains low for 55 ms (typ) after VCC rises above the reset threshold 3 V CC VREF VCC RESET RESET 2 VREF t1 t1 = RESET TIME = 55ms TYP. VREF = RESET VOLTAGE THRESHOLD Figure 2. Power Fail Reset Timing Table I. RESET Threshold Options PIN CONFIGURATION ADM8095S/L VREF t1 Supply voltage being monitored. GND 1 VREF Model RESET Threshold ADM809-5LART ADM809-5SART 4.63 V 2.93 V 3 VCC TOP VIEW (Not to Scale) ORDERING GUIDE Model Reset Threshold Temperature Range Branding Information Quantity ADM809-5LART-REEL ADM809-5LART-REEL-7 ADM809-5SART-REEL ADM809-5SART-REEL-7 ADM809-5SCHIPS 4.63 V 4.63 V 2.93 V 2.93 V 2.93 V –40°C to +150°C –40°C to +150°C –40°C to +150°C –40°C to +150°C –40°C to +150°C M9L M9L M9S M9S NA 10K 3K 10K 3K 1 Wafer REV. 0 –3– ADM809-5S/L –Typical Performance Characteristics 30 VOD = VTH – VCC 180 350 VOD = 10mV 160 20 VCC = 3V RESET DELAY 300 250 TITLE SUPPLY CURRENT 25 200 400 VCC = 5V 15 200 150 10 ADM8_L/M 140 120 100 VOD = 20mV 80 60 100 0 –40 VOD = 100mV 40 5 50 ADM8_R/S/T VCC = 1V –20 0 20 40 60 TEMPERATURE – ⴗC 10 100 1000 TITLE TPC 1. Supply Current vs. Temperature (No Load) 180 0 1 80 85 20 TPC 2. Maximum Transient Duration Without Causing a RESET Pulse vs. RESET Comparator Overdrive VOD = VTH – VCC 1.002 VOD = 10mV 1.0015 0 –40 VOD = 200mV –20 0 20 40 60 TEMPERATURE – ⴗC 80 85 TPC 3. Power-Down RESET Delay vs. Temperature ADM809-5L 160 120 100 THRESHOLD RESET DELAY 140 VOD = 20mV 80 60 40 1.0005 1.0 VOD = 100mV 0.9995 20 0 –40 1.001 VOD = 200mV –20 0 20 40 60 TEMPERATURE – ⴗC 80 85 TPC 4. Power-Down RESET Delay vs. Temperature ADM809-5S 0.999 –40 –20 0 20 40 60 TEMPERATURE – ⴗC 80 85 TPC 5. Normalized RESET Voltage Threshold vs. Temperature –4– REV. 0 ADM809-5S/L INTERFACING TO OTHER DEVICES OUTPUT The ADM809-5S/L is designed to integrate with as many devices as possible and therefore has an output dependant on VCC. Because of this design approach, interfacing this device to other devices is simplified. PRIORITY ENCODER 4 LINE BCD TO µP 74LS147 VCC ENSURING A VALID RESET OUTPUT DOWN TO V CC = 0 V When VCC falls below 0.8 V, ADM809-5S/L’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. VCC ADM809 OTHER SENSING DEVICES RESET VCC GND VCC Figure 4. Interfacing to µ Ps with Multiple Interrupts ADM809-5S/L RESET 3.3V 100nF 100k⍀ VCC RESET GND ADM809-5S/L 47k⍀ 47k⍀ GND Figure 3. Ensuring a Valid RESET Output Down to VCC = 0 V THE BENEFITS OF A VERY ACCURATE RESET THRESHOLD Figure 5. Alternative Application Circuit with Extra Decoupling 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 ADM809-5S/L series can operate effectively even when there are large degradations of the supply voltages. Another advantage of the ADM809-5S/L series is its very accurate internal voltage reference circuit. These benefits combine to produce an exceptionally reliable Voltage Monitor Circuit. 3.3V 100nF VCC RESET 22k⍀ ADM809-5S/L GND 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 ADM809-5S/L can easily be integrated into existing interrupt-handling circuits (Figure 6) or used as a stand-alone device. REV. 0 Figure 6. Additional Decoupling Can Be Achieved Using a 100 nF Capacitor Between VCC and Ground –5– ADM809-5S/L OUTLINE DIMENSIONS Dimensions shown in inches and (mm). Surface Mount Package RT-3 0.0550 (1.397) 0.0470 (1.194) 3 1 2 C00090–2.5–9/00 (rev. 0) 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) 0.0100 (0.254) 0.0050 (0.127) 0.0059 (0.150) 0.0034 (0.086) 0.027 (0.686) REF PRINTED IN U.S.A. 0.0040 (0.102) 0.0005 (0.013) 0.0440 (1.118) 0.0320 (0.813) –6– REV. 0