LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT T H E I P N F I N I T E O W E R I O F P N N O VA T I O N R O D U C T I O N DESCRIPTION The LX7001 is an improved undervoltage sensing circuit specifically designed for use as a reset controller in microprocessor-based systems. Today's complex miniaturized systems present difficult challanges to the system designer such as overcoming spurious noise problems. The LX7001 is optimized for systems that must be tolerant of high-speed power supply glitches caused by high-speed logic transitions and similar switching phenomena. The LX7001 offers a unique stage that couples glitch immunity with a micropower, ultrastable band-gap reference for precision sensing of undervoltage conditions. It offers the designer an D A T A S H E E T K E Y F E AT U R E S ■ Fully Characterized, Transient Immune Input Stage (See Product Highlight) economical, space-efficient solution for low supply voltage detection when used in combination with a single pull-up resistor. Adding one capacitor offers the functionality of a programmable delay time after power returns. Additionally, the LX7001 offers excellent temperature stability. A high-quality trimmed voltage reference and bias circuit permit very accurate and repeatable undervoltage sensing. The remaining blocks consist of a comparator with hysteresis, high current clamping diode and open collector output stage capable of sinking up to 60mA. The LX7001's RESET output is specified to be fully functional at VIN=1V. ■ Monitors 5V Supplies (VTRIP=4.6V Typ.) ■ Outputs Fully Defined At VCC=1V ■ Ultra-Low Supply Current (500µA Max. Over Temp) ! Temperature Compensated ICC For Extremely Stable Current Consumption ! µP Reset Function Programmable With 1 External Resistor And Capacitor ! Comparator Hysteresis Prevents Output Oscillation ! Electrically Compatible With Motorola MC34064 ! Pin-to-Pin Compatible With Motorola MC34064/MC34164 NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com. A P P L I C AT I O N S PRODUCT HIGHLIGHT ■ All Microprocessor Or Microcontroller Designs Using 5V Supplies INPUT TRANSIENT IMMUNITY ■ Simple 5V Undervoltage Detection (tn) Noise Pulse Width - (µs) 100 ACTIVE 10 1 IMMUNE 0.1 100 1000 (en) Noise Pulse Amplitude - (mV) PA C K A G E O R D E R I N F O R M A T I O N SOIC DM Plastic 8-pin TA (°C) TO-92 LP Plastic 3-pin Dip Y Ceramic 8-pin 0 to 70 LX7001CDM LX7001CLP — -40 to 85 LX7001IDM LX7001ILP — — — LX7001MY -55 to 125 Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX7001CDMT) Copyright © 1999 Rev. 1.2 6/99 LINFINITY MICROELECTRONICS INC. 11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570 1 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T (Note 1) Input Supply Voltage (VIN) ............................................................................... -1V to 12V RESET Output Voltage (VOUT) .......................................................................... -1V to 12V Output Sink Current (IOL) ............................................................ Internally Limited (mA) Clamp Diode Forward Current (IF), Pin 1 to pin 2 ............................................... 100mA Operating Junction Temperature Ceramic (Y - Package) .......................................................................................... 150°C Plastic (DM, LP - Packages) .................................................................................. 150°C Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C Note 1. Values beyond which damage may occur. All voltages are specified with respect to ground, and all currents are positive into the specified terminal. PA C K A G E P I N O U T S RESET VIN N.C. GROUND 1 8 2 7 3 6 4 5 N.C. N.C. N.C. N.C. Y PACKAGE (Top View) RESET VIN N.C. GROUND 1 8 2 7 3 6 4 5 N.C. N.C. N.C. N.C. DM PACKAGE (Top View) T H E R M A L D ATA DM PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 165°C/W LP PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 3. GROUND 156°C/W Y PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 1. RESET 130°C/W Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow 2 2. VIN LP PACKAGE (Top View) Copyright © 1999 Rev. 1.2 6/99 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P D R O D U C T I O N A T A S H E E T R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S Parameter Symbol Input Supply Voltage RESET Output Voltage Clamp Diode Forward Current Operating Ambient Temperature Range: LX7001C LX7001I LX7001M VIN VOUT IF (Note 2) Recommended Operating Conditions Min. Typ. Max. 1 Units 10 V V 70 85 125 °C °C °C 10 50mA 0 -25 -55 Note 2. Range over which the device is functional. ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures of 0°C ≤ TA ≤ 70°C for the LX7001C, -40°C ≤ TA ≤ 85°C for the LX7001I, and -55°C ≤ TA ≤ 125°C for the LX7001M. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.) Parameter Symbol Test Conditions LX7001C/7001I/7001M Min. Typ. Max. Units Comparator Section Threshold Voltage High State Output Low State Output Hysteresis VT+ VTVH VIN Increasing — 4V to 5V VIN Decreasing — 5V to 4V 4.5 4.5 0.01 4.62 4.60 0.02 4.7 4.7 0.05 V V V 10 0.06 0.25 0.3 40 0.01 0.02 0.82 1.0 0.4 0.1 60 0.5 2.0 1.2 V V V mA µA µA V 345 500 µA RESET Output Section Output Sink Saturation Voltage Output Sink Current Output Off-State Leakage IOL IOH Clamp Diode Forward Voltage VF VIN = 4.0V, IOL = 8.0mA VIN = 4.0V, IOL = 2.0mA VIN = 1.0V, IOL = 0.1mA VOUT = 4.0V VOUT = 5.0V VOUT = 10V Pin 1 to pin 2, IF = 10mA ICC VIN = 5.0V VOL 0.6 Total Device Supply Current Copyright © 1999 Rev. 1.2 6/99 3 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D A T A S H E E T BLOCK DIAGRAM VIN RESET 1.2 VREF GROUND GRAPH / CURVE INDEX FIGURE INDEX Characteristic Curves Application Circuits FIGURE # FIGURE # 1. RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE 13. LOW VOLTAGE MICROPROCESSOR RESET 2. POWER-UP RESET VOLTAGE 14. SWITCHING THE LOAD OFF WHEN BATTERY REACHES BELOW 4.3V 3. RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE 15. VOLTAGE MONITOR 4. THRESHOLD VOLTAGE vs. TEMPERATURE 16. MOSFET LOW VOLTAGE GATE DRIVE PROTECTION 5. THRESHOLD HYSTERESIS vs. TEMPERATURE 6. SUPPLY CURRENT vs. INPUT VOLTAGE 17. LOW VOLTAGE MICROPROCESSOR RESET with ADDITIONAL HYSTERESIS 7. SUPPLY CURRENT vs. TEMPERATURE 8. LOW LEVEL OUTPUT CURRENT vs. TEMPERATURE 9. LOW LEVEL OUTPUT VOLTAGE vs. LOW LEVEL OUTPUT CURRENT 10. VOLTAGE vs. CLAMP DIODE FORWARD CURRENT 11. PROPAGATION DELAY 12. LOW LEVEL OUTPUT VOLTAGE vs. TEMPERATURE 4 Copyright © 1999 Rev. 1.2 6/99 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D CHARACTERISTIC FIGURE 1. — RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE H E E T CURVES FIGURE 2. — POWER-UP RESET VOLTAGE 2.0 10 RL = 10K 1.8 TA = 25 C Power-Up RESET Voltage - (V) (VOUT) RESET Output Voltage - (V) S A T A 8 6 4 2 1.6 1.4 VIN 1.2 1.0 0.8 0.6 RESET 0.4 0.2 0 0 0 2 4 6 8 100 0 10 4.64 VT+ Upper Threshold High State Output 4 (VT) Threshold Voltage - (V) (VOUT) RESET Output Voltage - (V) 500 FIGURE 4. — THRESHOLD VOLTAGE vs. TEMPERATURE 5 3 2 1 0 4.55 4.56 4.57 4.58 4.59 4.60 4.61 4.62 4.63 4.64 4.65 (VIN) Input Voltage - (V) Copyright © 1999 Rev. 1.2 6/99 400 (t) Time - ( s) (VIN) Input Voltage - (V) FIGURE 3. — RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE 300 200 4.62 4.60 VT- Lower Threshold Low State Output 4.58 4.56 4.54 -55 -25 0 25 50 75 100 125 150 (TJ) Temperature - ( C) 5 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D CHARACTERISTIC FIGURE 5. — THRESHOLD HYSTERESIS vs. TEMPERATURE S A T A H E E T CURVES FIGURE 6. — SUPPLY CURRENT vs. INPUT VOLTAGE 30 1000 -55 C 26 (ICC) Supply Current - ( A) (VH) Hysteresis Voltage - (mV) RESET Load = 10K 22 18 14 10 -55 800 -40 C +25 C 600 400 +85 C +125 C 200 0 -25 0 25 50 75 100 125 2 0 150 (TJ) Temperature - ( C) 8 10 (VIN) Input Voltage - (V) FIGURE 7. — SUPPLY CURRENT vs. TEMPERATURE FIGURE 8. — LOW LEVEL OUTPUT CURRENT vs. TEMPERATURE 80 1200 1100 1000 900 800 700 600 10V 500 400 300 5V 200 (IOL) Low Level Output Current - (mA) 1300 (ICC) Supply Current - ( A) 6 4 70 60 50 40 30 20 10 100 0 -55 -25 0 25 50 75 100 (TJ) Temperature - ( C) 6 125 150 0 -55 -25 0 25 50 75 100 125 150 (TJ) Temperature - ( C) Copyright © 1999 Rev. 1.2 6/99 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D CHARACTERISTIC H E E T CURVES FIGURE 10. — VOLTAGE vs. CLAMP DIODE FORWARD CURRENT FIGURE 9. — LOW LEVEL OUTPUT VOLTAGE vs. LOW LEVEL OUTPUT CURRENT 1.2 2000 1.1 -55 C 1500 25 C 125 C 1000 500 -40 C 1 0.9 0.8 125 C 85 C 0.7 25 C 0.6 0 0 10 20 30 0.5 40 0 10 (ISINK) Low Level Output Current - (mA) 5.5 (VOL) Low Level Output Voltage - (mV) VIN - (V) 4V RESET REF 4.5 4.0 RESET - (V) 6.0 4.0 2.0 0 0 2 4 6 40 50 60 70 80 90 100 80 10K 5V 5.0 30 FIGURE 12. — LOW LEVEL OUTPUT VOLTAGE vs. TEMPERATURE VIN TA = 25 C 20 (IF) Forward Current - (mA) FIGURE 11. — PROPAGATION DELAY 8 10 (t) Time - ( s) Copyright © 1999 Rev. 1.2 6/99 -55 C RESET = 0V VIN = 4V (VF) Forward Voltage - (V) (VOL) Low Level Output Voltage - (mV) S A T A 12 14 16 70 VIN = 1V ISINK = 100 A 60 50 40 30 20 10 0 -55 -25 0 25 50 75 100 125 150 (TJ) Temperature - ( C) 7 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D A T A S H E E T T Y P I C A L A P P L I C AT I O N C I R C U I T S FIGURE 14. — SWITCHING THE LOAD OFF WHEN BATTERY REACHES BELOW 4.3V. FIGURE 13. — LOW VOLTAGE MICROPROCESSOR RESET. VIN R RESET POWER SUPPLY CDLY MICROPROCESSOR CIRCUIT VIN LOAD 1.2 VREF RESET A time delayed reset can be accomplished with the addition of CDLY. For systems with extremely fast power supply rise times (< 500ns) it is recommended that the RCDLY time constant be greater than 5.0µs. VTH(MPU) is the microprocessor reset input threshold. tDLY = R CDLY In 1.2 VREF 1 VTH(MPU) 1VIN FIGURE 15. — VOLTAGE MONITOR. FIGURE 16. — MOSFET LOW VOLTAGE GATE DRIVE PROTECTION. VCC 1.0k VIN RL 270 4.3V SMP60N03-10L VIN RESET POWER SUPPLY RESET 1.2 VREF 1.2 VREF Overheating of the logic level power MOSFET due to insufficient gate voltage can be prevented with the above circuit. When the input signal is below the 4.3 volt threshold of the LX7001C, its output grounds the gate of the L2 MOSFET. 8 Copyright © 1999 Rev. 1.2 6/99 PRODUCT DATABOOK 1996/1997 LX7001 T RANSIENT I MMUNE U NDERVOLTAGE S ENSING C IRCUIT P R O D U C T I O N D A T A S H E E T T Y P I C A L A P P L I C AT I O N C I R C U I T S (Con't.) FIGURE 17. — LOW VOLTAGE MICROPROCESSOR RESET with ADDITIONAL HYSTERESIS. TEST DATA RH IIN VIN POWER SUPPLY RL RESET MICROPROCESSOR CIRCUIT VH = 1.2 VREF 4.6 RH + 0.02 RL ∆VTH (LOWER) = 340 RH x 10-6 Where: RH ≤ 150Ω RL ≥ 1.5Ω ≤ 10kΩ Comparator hysteresis can be increased with the addition of resistor RH. The hysteresis equation has been simplified and does not account for the change of input current IIN as VCC crosses the comparator threshold. An increase of the lower threshold ∆VTH (LOWER) will be observed due to IIN which is typically 340µA at 4.59V. The equations are accurate to ±10% with RH less than 150Ω and RL between 1.5kΩ and 10kΩ. VH (mV) 20 51 40 81 71 112 100 164 190 327 276 480 ∆VTH (mV) 0 3.4 6.8 6.8 10 10 16 16 34 34 51 51 RH (Ω) 0 10 20 20 30 30 47 47 100 100 150 150 RL (Ω) 0 1.5 4.7 1.5 2.7 1.5 2.7 1.5 2.7 1.5 2.7 1.5 PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 1999 Rev. 1.2 6/99 9