Microprocessor Supervisory Circuit in 4-Lead SC70 ADM6384 FEATURES FUNCTIONAL BLOCK DIAGRAMS ADM6384 VCC RESET GENERATOR VREF MR RESET GND DEBOUNCE 05305-001 Precision power supply monitoring 31 reset threshold options 1.58 V to 5.0 V Four reset timeouts 1 ms, 20 ms, 140 ms, 1120 ms Manual reset input Reset output stage Push-pull active-low Guaranteed reset output valid to VCC = 1 V Power supply glitch immunity Specified over −40°C to +125°C temperature range 4-lead SC70 package Figure 1. VCC VCC APPLICATIONS μP ADM6384 MR RESET RESET 100kΩ GND GND 05305-002 Microprocessor systems Computers Controllers Intelligent instruments Portable equipment Figure 2. GENERAL DESCRIPTION The ADM6384 is a supervisory circuit that monitors power supply voltage levels in microprocessor-based systems. A power-on reset signal is generated when the supply voltage rises to a preset threshold level. The debounced manual reset input of the ADM6384 can be used to initiate a reset by means of an external push-button or logic signal. The part is available in a choice of 31 reset threshold options, from 1.58 V to 5.0 V. The minimum reset timeout periods are 1 ms, 20 ms, 140 ms, and 1120 ms. The ADM6384 is available in a 4-lead SC70 package and typically consumes only 7 μA, making it suitable for use in low power, portable applications. 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 that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 © 2005 Analog Devices, Inc. All rights reserved. ADM6384 TABLE OF CONTENTS Specifications..................................................................................... 3 Manual Reset Input .......................................................................9 Absolute Maximum Ratings............................................................ 5 Application Information................................................................ 10 ESD Caution.................................................................................. 5 Negative-Going VCC Transients ................................................ 10 Pin Configuration and Function Descriptions............................. 6 Ensuring Reset Valid to VCC = 0 V ........................................... 10 Typical Performance Characteristics ............................................. 7 Outline Dimensions ....................................................................... 11 Circuit Description........................................................................... 9 Ordering Guide .......................................................................... 11 Reset Output ................................................................................. 9 REVISION HISTORY 7/05—Revision 0: Initial Version Rev. 0 | Page 2 of 12 ADM6384 SPECIFICATIONS VCC = full operating range; TA = −40°C to +125°C, unless otherwise noted. Table 1. Parameter SUPPLY VCC Operating Voltage Range Supply Current RESET THRESHOLD VOLTAGE ADM6384x50x ADM6384x49x ADM6384x48x ADM6384x47x ADM6384x46x ADM6384x45x ADM6384x44x ADM6384x43x ADM6384x42x ADM6384x41x ADM6384x40x ADM6384x39x ADM6384x38x ADM6384x37x ADM6384x36x ADM6384x35x ADM6384x34x ADM6384x33x ADM6384x32x ADM6384x31x ADM6384x30x ADM6384x29x ADM6384x28x ADM6384x27x ADM6384x26x ADM6384x25x ADM6384x24x ADM6384x23x ADM6384x22x ADM6384x17x ADM6384x16x RESET THRESHOLD TEMPERATURE COEFFICIENT VCC to RESET DELAY RESET THRESHOLD HYSTERESIS RESET TIMEOUT PERIOD ADM6384xxD1 ADM6384xxD2 ADM6384xxD3 ADM6384xxD4 Min Typ 1 7 6 4 3 4.88 4.78 4.68 4.58 4.51 4.39 4.27 4.19 4.1 4.0 3.9 3.8 3.71 3.61 3.51 3.41 3.32 3.22 3.12 3.00 2.93 2.85 2.73 2.63 2.56 2.44 2.34 2.26 2.13 1.62 1.54 5.00 4.90 4.80 4.70 4.63 4.5 4.38 4.30 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.08 3.0 2.93 2.8 2.70 2.63 2.5 2.4 2.31 2.19 1.67 1.58 60 35 Max 5.5 13 11 7 6 V μA μA μA μA 5.12 5.02 4.92 4.82 4.74 4.61 4.48 4.41 4.31 4.2 4.1 4.0 3.9 3.79 3.69 3.59 3.49 3.38 3.28 3.15 3.08 3.00 2.87 2.77 2.69 2.56 2.46 2.37 2.24 1.71 1.61 V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V ppm/°C μs 2 x VTH 1 20 140 1120 Rev. 0 | Page 3 of 12 Unit mV 2 40 280 2240 ms ms ms ms Test Conditions/Comments VCC = 5.5 V, no load VCC = 3.6 V, no load VCC = 2.5 V, no load 1 VCC = 1.8 V, no load1 VCC falling at 10 mV/μs from VTH + 100 mV to VTH − 100 mV ADM6384 Parameter MANUAL RESET INPUT MR Input Threshold VIL Min VIH 0.7 × VCC 2.4 1 MR Input Pulse Width MR Glitch Rejection MR Pull-Up Resistance MR to Reset Delay Typ 0.3 × VCC 0.8 100 63 200 32 RESET Output Voltage VOL VOH 1 Max 100 0.3 0.3 0.4 0.8 × VCC 0.8 × VCC TA = 25oC only. Rev. 0 | Page 4 of 12 Unit Test Conditions/Comments V V V V μs ns kV ns VCC < 4 V VCC > 4 V VCC < 4 V VCC > 4 V V V V V V VCC > = 1.0 V, ISINK = 80 μA VCC > = 2.5 V, ISINK = 1.2 mA VCC > = 4.5 V, ISINK = 3.2 mA VCC > = 2.5 V, ISOURCE = 500 μA VCC > = 4.5 V, I SOURCE = 800 μA ADM6384 ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. Table 2. Parameter VCC RESET Output Current ( RESET) Operating Temperature Range Storage Temperature Range θJA Thermal Impedance, SC70 Soldering Temperature Sn/Pb Pb-Free Rating −0.3 V to +6 V −0.3 V to +6 V 20 mA −40°C to +125°C −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 indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 331°C/W 240°C, 30 sec 260°C, 40 sec ESD 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 this product 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. Rev. 0 | Page 5 of 12 ADM6384 GND 1 4 VCC 3 MR ADM6384 TOP VIEW (Not to Scale) RESET 2 05305-003 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Figure 3. Pin Configuration Table 3. Pin Function Descriptions Pin No. 1 2 Name GND RESET 3 MR 4 VCC Description Ground. Active-Low Reset Output. Asserted whenever VCC is below the reset threshold, VTH. Push-pull output stage. Manual Reset Input. This is an active-low input which, when forced low for at least 1 μs, generates a reset. It features a 52 kV internal pull-up. Power Supply Voltage Being Monitored. Rev. 0 | Page 6 of 12 ADM6384 TYPICAL PERFORMANCE CHARACTERISTICS 10.0 1.05 9.5 1.04 NORMALIZED RESET THRESHOLD 9.0 8.5 8.0 7.0 6.5 6.0 5.5 5.0 4.5 1.01 1.00 0.99 0.98 0.97 0.96 4.0 –20 0 20 40 60 TEMPERATURE (°C) 80 100 120 0.95 –40 04535-006 3.5 –40 1.02 Figure 4. Supply Current vs. Temperature –20 0 20 40 60 TEMPERATURE (°C) 80 100 120 04535-010 ICC (μA) 7.5 1.03 Figure 7. Normalized Reset Threshold vs. Temperature 100 0.20 90 0.15 70 60 VOUT (V) VCC TO RESET DELAY (μs) 80 50 40 0.10 30 0.05 20 10 20 40 60 TEMPERATURE (°C) 80 100 120 0 0 Figure 5. VCC to RESET Output Delay vs. Temperature 1 2 3 4 ISINK (mA) 5 6 7 04535-017 0 1.0 04535-018 –20 04535-008 0 –40 Figure 8. Output Voltage Low vs. ISINK 1.20 2.92 2.90 1.10 1.05 VOUT (V) 2.88 1.00 0.95 2.86 0.90 2.84 0.85 0.80 –40 –20 0 20 40 60 TEMPERATURE (°C) 80 100 120 04535-007 NORMALIZED RESET TIMEOUT 1.15 Figure 6. Normalized Reset Timeout Period vs. Temperature 2.82 0 0.2 0.4 0.6 ISOURCE (mA) 0.8 Figure 9. Output Voltage High vs. ISOURCE Rev. 0 | Page 7 of 12 ADM6384 340 140 120 100 VTH = 4.63V 80 60 40 20 VTH = 2.93V 0 10 100 OVERDRIVE VOD (mV) 1000 Figure 10. Maximum VCC Transient Duration vs. Reset Threshold Overdrive Rev. 0 | Page 8 of 12 320 300 280 260 240 220 200 180 160 140 120 100 –40 –20 0 20 40 60 TEMPERATURE (°C) 80 100 120 Figure 11. Manual Reset Minimum Pulse Width vs. Temperature 05305-011 MANUAL RESET TO RESET DELAY (ns) RESET OCCURS ABOVE CURVE 05305-010 MAXIMUM TRANSIENT DURATION (μs) 160 ADM6384 CIRCUIT DESCRIPTION RESET OUTPUT The ADM6384 features an active-low push-pull reset output. The reset signal is guaranteed to be logic low for VCC down to 1 V. The reset output is asserted when VCC is below the reset threshold (VTH) or when MR is driven low. Reset remains asserted for the duration of the reset active timeout period (tRP) after VCC rises above the reset threshold or after MR transitions from low to high. Figure 12 illustrates the behavior of the reset outputs. VCC VCC VTH VTH 1V 0V VCC RESET tRP 0V tRD 05305-012 The ADM6384 provides microprocessor supply voltage supervision by controlling the microprocessor’s reset input. Code execution errors are avoided during power-up, powerdown, and brownout conditions by asserting a reset signal when the supply voltage is below a preset threshold. In addition, the ADM6384 allows supply voltage stabilization with a fixed timeout before the reset deasserts after the supply voltage rises above the threshold. If the user detects a problem with the system’s operation, a manual reset input is available to reset the microprocessor by means of an external push-button, for example. Figure 12. Reset Timing Diagram MANUAL RESET INPUT The ADM6384 features a manual reset input (MR) which, when driven low, asserts the reset output. When MR transitions from low to high, reset remains asserted for the duration of the reset active timeout period before deasserting. The MR input has a 52 kΩ internal pull-up so that the input is always high when unconnected. An external push-button switch can be connected between MR and ground so that the user can generate a reset. Debounce circuitry for this purpose is integrated on-chip. Noise immunity is provided on the MR input, and fast, negative-going transients of up to 100 ns (typ) are ignored. A 0.1 μF capacitor between MR and ground provides additional noise immunity. Rev. 0 | Page 9 of 12 ADM6384 APPLICATION INFORMATION NEGATIVE-GOING VCC TRANSIENTS ENSURING RESET VALID TO VCC = 0 V To avoid unnecessary resets caused by fast power supply transients, the ADM6384 is equipped with glitch rejection circuitry. The typical performance characteristic in Figure 10 plots VCC transient duration versus the transient magnitude. The curves show combinations of transient magnitude and duration for which a reset is not generated for 4.63 V and 2.93 V reset threshold parts. For example, with the 2.93 V threshold, a transient that goes 100 mV below the threshold and lasts 8 μs typically does not cause a reset, but if the transient is any bigger in magnitude or duration, a reset is generated. An optional 0.1 μF bypass capacitor mounted close to VCC provides additional glitch rejection. Both active-low and active-high reset outputs are guaranteed to be valid for VCC as low as 1 V. However, by using an external resistor with push-pull configured reset outputs, valid outputs for VCC as low as 0 V are possible. For an active-low reset output, a resistor connected between RESET and ground pulls the output low when it is unable to sink current. A large resistance such as 100 kΩ should be used so that it does not overload the reset output when VCC is above 1 V. VCC ADM6384 RESET 05305-013 100kΩ GND Figure 13. Ensuring Reset Valid to VCC = 0 V Rev. 0 | Page 10 of 12 ADM6384 OUTLINE DIMENSIONS 2.20 1.80 1.35 1.15 3 4 1 2.40 1.80 2 PIN 1 0.50 BSC 0.65 BSC 1.10 0.80 1.00 0.80 0.10 MAX 0.30 0.15 12° 8° 0.40 0.10 SEATING *0.70 PLANE 0.50 0.18 0.10 0.30 0.10 0.10 COPLANARITY *PACKAGE OUTLINE CORRESPONDS IN FULL TO EIAJ SC82 EXCEPT FOR WIDTH OF PIN-2 AS SHOWN Figure 14. 4-Lead Thin Shrink Small Outline Transistor Package [SC70] (KS-4) Dimensions shown in millimeters ADM6384YKS_ x_ x D_-RL7 x ORDERING QUANTITY RL7: 3,000 PIECE REEL RESET TIMEOUT PERIOD 1: 1ms (MIN) 2: 20ms (MIN) 3: 140s (MIN) 4: 1120s (MIN) PACKAGE CODE KS: 4-LEAD SC70 Z: LEAD FREE RESET THRESHOLD NUMBER (16 TO 50) 05305-014 GENERIC NUMBER TEMPERATURE RANGE Y: –40°C TO +125°C Figure 15. Ordering Code Structure ORDERING GUIDE Standard Models 1 ADM6384YKS29D1-RL7 ADM6384YKS23D3-RL7 ADM6384YKS29D3-RL7 1 Reset Threshold (V) 2.93 2.31 2.93 Reset Timeout (ms) 1 140 140 Temperature Range −40°C to +125°C −40°C to +125°C −40°C to +125°C Quantity 3k 3k 3k Package Type SC70-4 SC70-4 SC70-4 Branding N0J N0J N0J If ordering nonstandard models, complete the ordering code shown in Figure 15 by inserting reset timeout and reset threshold suffixes. Contact Sales for availability of nonstandard models. Rev. 0 | Page 11 of 12 ADM6384 NOTES © 2005 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05305–0–7/05(0) Rev. 0 | Page 12 of 12