Impala Linear Corporation ILC811/812 Preliminary Microprocessor Reset Circuits General Description Features The ILC811/ILC812 is a low cost microprocessor supervisory circuit that asserts a reset if the power supply drops below a designated threshold or the manual reset pin is forced low. Several different reset thresholds are available to accommodate systems operating at 3V, 3.3V or 5V. The ILC811 has an active low RESET output, while the ILC812 offers an active high RESET output. The reset output is guaranteed to remain asserted for a minimum of 140ms after VCC has risen above the designated reset threshold. The ILC811/ILC812 is available in a 4-pin SOT-143 Typical Circuit MR VCC ILC811 ILC812 µP RESET (RESET) Applications ! Critical Microprocessor Power Monitoring ! Portable Equipment ! Intelligent Instruments ! Computers & Printers ! Controllers VCC VCC ! Precision Voltage Monitor for 3V, 3.3V or 5V Power Supplies ! 6mA Supply Current ! 140ms Minimum Reset Pulse Width ! RESET Remains Valid with VCC as Low as 1.4V ! Active Low Manual Reset Input ! No External Components ! 4-Pin SOT-143 Package RESET INPUT Ordering Information Part ILC811_U ILC812_U ( ) = ILC812 Reset Threshold Voltage (V) 4.63 4.38 4.00 3.08 2.93 2.63 Top View 4 VCC 2 3 MR GND 1 4 VCC 3 MR ILC811 RESET Temp. Range -40°C to +85°C -40°C to +85°C Place the device suffix of desired reset threshold voltage from the table [below] in the blank to complete the part number. Pin Package Configuration GND 1 Package 4-Lead SOT-143 4-Lead SOT-143 Device Suffix L M J T S R ILC812 RESET 2 Impala Linear Corporation ILC811/812 1.3 (408) 574-3939 www.impalalinear.com Sept 1999 1 Microprocessor Reset Circuits Preliminary Absolute Maximum Ratings Parameter Terminal Voltage Input Current Output Current Rate of Rise Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering - 10 sec.) Power Dissipation (TA = +70°C) Symbol VCC MR VCC, MR RESET, RESET VCC TA Ratings -0.3 to 6.0 -0.3 to (VCC + 0.3) 20 20 100 -40 to +85 -65 to +150 300 320 Units V V mA mA V/µs °C °C °C mW Stresses above those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent device failure. Functionality at or above these limits is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability. Operating ranges define those limits between which the functionality of the device is guaranteed. Electrical Characteristics VCC = 5V for ILC81_L/M/J, VCC = 3.3V for ILC81_S/T, VCC = 3V for ILC81_R, TA = Operating Temperature Range, unless otherwise noted. Parameter Operating Voltage Range, VCC Supply Current, ICC Reset Voltage Threshold, VTH Conditions TA = 0°C to 70°C TA = -40°C to 85°C ILC811L/M/J, ILC812L/M/J VCC < 3.6V, ILC811R/S/T, ILC812R/S/T ILC811L, ILC812L ILC811M, ILC812M ILC811J, ILC812J ILC811T, ILC812T ILC811S, ILC812S ILC811R, ILC812R Reset Timeout Period, tR RESET Output Voltage, VOH RESET Output Voltage, VOL RESET Output Voltage, VOH RESET Output Voltage, VOL Min 1.4 1.6 4.50 4.25 3.89 3.00 2.85 2.55 140 ISOURCE = 800µA, ILC811L/M/J ISOURCE = 500µA, ILC811R/S/T VCC = VTH Min., ISINK = 3.2mA, ILC811L/M/J VCC = VTH Min., ISINK = 1.2mA, ILC811R/S/T VCC > 1.4V, ISINK = 50µA, TA = 0°C to 70°C VCC > 1.6V, ISINK = 50µA, TA = -40°C to 85°C VCC – 1.5 0.8 x VCC 1.8V < VCC < VTH Min., ISOURCE= 150µA ISINK = 3.2mA, ILC812L/M/J ISINK = 1.2mA, ILC812R/S/T 0.8 x VCC V ms V V V 0.4 0.3 VCC > VTH Max., ILC81_L/M/J ILC81_R/S/T VCC > VTH Max., ILC81_L/M/J ILC81_R/S/T V µs µs 2.3 0.7 x VCC 10 V 20 100 MR Glitch Immunity Impala Linear Corporation µA 0.5 MR Pull-Up Resistance ILC811/812 1.3 Units V 0.4 0.3 0.3 0.3 MR to Reset Delay MR Input Threshold, VIL 9 6 4.63 4.38 4.00 3.08 2.93 2.63 240 Max 5.5 5.5 15 10 4.75 4.50 4.10 3.15 3.00 2.70 560 10 MR Minimum Pulse Width MR Input Threshold, VIH Typ (408) 574-3939 www.impalalinear.com 0.8 0.25 x VCC 30 V kΩ ns Sept 1999 2 Microprocessor Reset Circuits Preliminary Pin Functions Pin Name Pin Number ILC811 ILC812 Description GND 1 1 Ground Pin. RESET 2 N/A RESET goes low if VCC falls below the reset threshold and remains asserted for one reset timeout period (140ms min.) after VCC exceeds the reset threshold. RESET N/A 2 RESET goes high if VCC falls below the reset threshold and remains asserted for one reset timeout period (140ms min.) after VCC exceeds the reset threshold. MR 3 3 Manual reset input. A logic low on MR forces a reset. The reset will remain asserted as long as MR is held low and for one reset timeout period (140ms min.) after MR goes high. This input can be shorted to ground via a switch or driven from CMOS or TTL logic. Float if unused. VCC 4 4 Power supply input, 3V, 3.3V or 5V. Circuit Description Microprocessor Reset The RESET pin is asserted whenever VCC falls below the reset threshold voltage or if MR (manual reset) is forced low. The reset pin remains asserted for a period of 240ms after VCC has risen above the reset threshold voltage or MR has returned high. The reset function ensures the microprocessor is properly reset and powers up into a known condition after a power failure. RESET will remain valid with VCC as low as 1.4V. MR tR tR RESET VCC Transients The ILC811/ILC812 are relatively immune to negative-going VCC glitches below the reset threshold. Typically, a negative-going transient 125µV below the reset threshold with a duration of 50ms (25µs for ILC81_R/S/T) or less will not cause an unwanted reset. Interfacing to Bidirectional Reset Pins The ILC811/ILC812 can interface with µPs with bidirectional reset pins by connecting a 4.7kΩ resistor in series with the ILC811/ILC812 output and the µP reset pin. Impala Linear Corporation ILC811/812 1.3 + - 4 Reset Threshold (V) MR RESET (ILC811) Reset Generator 2 RESET (ILC812) 3 1 GND RESET Valid to 0V A resistor can be added from the RESET pin to ground to ensure the RESET output remains low with VCC down to 0V. A 100kW resistor connected from RESET to ground is recommended. The size of the resistor should be large enough to not load the RESET output and small enough to pull-down any stray leakage currents. VTH VCC VCC (408) 574-3939 VCC VCC VCC ILC811 µP RESET RESET 100 K Reset Valid to VCC =0V www.impalalinear.com Sept 1999 3 Microprocessor Reset Circuits Preliminary Alternate Source Cross Reference Guide Industry P/N MAX811JEUS-T MAX811LEUS-T MAX811MEUS-T MAX811REUS-T MAX811SEUS-T MAX811TEUS-T MAX812JEUS-T MAX812LEUS-T MAX812MEUS-T MAX812REUS-T MAX812SEUS-T MAX812TEUS-T ILC Direct Replacement ILC811JU ILC811LU ILC811MU ILC811RU ILC811SU ILC811TU ILC812JU ILC812LU ILC812MU ILC812RU ILC812SU ILC812TU Device Marking Information SOT-143 ILC811J KJYY ILC811L KLYY ILC811M KMYY ILC811R KRYY ILC811S KSYY ILC811T KTYY ILC812J LJYY ILC812L LLYY ILC812M LMYY ILC812R LRYY ILC812S LSYY ILC812T LTYY YY = Lot Code Impala Linear Corporation ILC811/812 1.3 (408) 574-3939 www.impalalinear.com Sept 1999 4 Microprocessor Reset Circuits Preliminary Packaging Information 4-Pin SOT-143 0.079 0.071 0.055 0.047 Dimensions are in inches 0.098 0.083 0.021 0.015 0.037 0.030 0.120 0.105 0.0059 0.0035 0.040 0.031 0.080 0.070 0-8° 0.010 0.005 0.004 0.001 Tape and Reel Information 4.0 ± 0.1 2.0 ± 0.05 O1.5 ± 0.1 1.75 ± 0.1 3.5 ± 0.05 8.0 ± 0.3 O1.1 ± 0.1 4.0 ± 0.1 2.7 ± 0.1 Dimensions are in millimeters 1.2 ± 0.1 3.1 ± 0.1 Devices sold by Impala Linear Corporation are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Impala Linear Corporation makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Impala Linear Corporation makes no warranty of merchantability or fitness for any purpose. Impala Linear Corporation reserves the right to discontinue production and change specifications and prices at any time and without notice. This product is intended for use in normal commercial applications. Applications requiring an extended temperature range, unusual environmental requirements, or high reliability applications, such as military and aerospace, are specifically not recommended without additional processing by Impala Linear Corporation. Life Support Policy Impala Linear Corporation’s products are not authorized for use as critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. Impala Linear Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in an Impala Linear Corporation product. No other circuits, patents, licenses are implied. Impala Linear Corporation ILC811/812 1.3 (408) 574-3939 www.impalalinear.com Sept 1999 5