AP1701 ANACHIP | Alldatasheet
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3-Pin Microprocessor Reset Circuits This datasheet contains new product information. Anachip Corp. re serves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev.1.0 May. 7, 2004 Features - Precision Monitoring of +3V, +3.3V, and +5V Power-Supply Voltages - Fully Specified Over Temperature - Available in Three Output Configurations - Push-Pull RESET Low Output (AP1701/3) - Push-Pull RESET High Output (AP1702/4) - 140ms min Power-On Reset Pulse Width - 12µA Supply Current - Guaranteed Reset Valid to VCC = +1V - Power Supply Transient Immunity - No External Components - 3-pin SOT23 package Applications - Computers - Controllers - Intelligent Instruments - Critical µP and µC Power Monitoring - Portable/Battery Powered Equipment - Automotive General Description The AP1701/2/3/4 are used for microprocessor (µP) supervisory circuits to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The AP1701/2/3/4 have push pull outputs. The AP1701/3 have an active low RESET output, while the AP1702/4 has an active high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V. Low supply current makes the AP1701/2/3/4 ideal for use in portable equipment. The AP1701/2/3/4 is available in a 3-pin SOT23 package. Pin Assignments (Top View) GND (RESET) VCC SOT-23 AP1701 AP1702 RESET (Top View) 2GND VCC SOT-23 AP1703 AP1704 (RESET)RESET Pin Descriptions Name Description GND Ground RESET (RESET) Reset output pin L: for AP1701/3 H: for AP1702/4 VCC Operating voltage input
3-Pin Microprocessor Reset Circuits Anachip Corp. Ordering Information AP170X X X X Enable 1: Active-Low 2: Active-High Voltage A: 4.63 B: 4.38 C: 4.00 D: 3.08 E: 2.93 F: 2.63 3: Active-Low 4: Active-High Package W:SOT23 Lead Free Blank : Normal L : Lead Free Package Absolute Maximum Ratings Symbol Parameter Rating Unit VCC Terminal Voltage (with respect to GND) -0.3 to +6.0 V VRESET RESET, RESET (push-pull) -0.3 to (VCC + 0.3) V ICC Input Current, V CC 20 mA IO Output Current, RESET, RESET 20 mA VR Rate of Rise, V CC 100 V/µS PD Continuous Power Dissipation (TA = +70°C), de-rate 4mW/°C above +70°C 320 mW TOP Operating Temperature Range -40 to +105 °C TST Storage Temperature Range -65 to +150 °C TLEAD Lead Temperature (soldering, 10s) +300 °C
3-Pin Microprocessor Reset Circuits Anachip Corp. Electrical Characteristics (TA=25ºC) Symbol Parameter Conditions Min. Typ. Max. Unit VCC V CC Range T A = 0oC to +70oC 1.0 5.5 V VCC < 5.5V 19 60 µA ICC Supply Current VCC < 3.6V 17 50 µA AP1701/2/3/4A 4.54 4.63 4.72 AP1701/2/3/4B 4.29 4.38 4.47 AP1701/2/3/4C 3.92 4.00 4.08 AP1701/2/3/4D 3.02 3.08 3.14 AP1701/2/3/4E 2.87 2.93 2.99 Reset Threshold TA=25ºC AP1701/2/3/4F 2.57 2.63 2.68 V VTH Reset Threshold Tempco 30 ppm/ oC VCC to Reset Delay V CC = VTH to (VTH – 100mV) 20 µs TDELAY Reset Active Timeout Period TA = 0oC to +70oC 100 240 380 ms VCC = VTH min, ISINK = 1.2mA, AP1701/3 0.3 VCC = VTH min, ISINK = 3.2mA 0.4 VOL TRESE Output Voltage Low VCC > 1.0V, ISINK = 50uA 0.3 V VCC > V TH max, I SOURCE = 500uA, AP1701/3 0.8VCC VOH TRESE Output Voltage-High VCC > VTH max, ISOURCE = 800uA V CC –1.5 V VCC = VTH max, ISINK = 1.2mA, AP1702/4 0.3 VOL RESET Output Voltage-Low VCC = VTH max, ISINK = 3.2mA 0.4 V VOH RESET Output Voltage-High 1.8V < VCC < VTH min, ISOURCE = 150uA, AP1702/4 0.8 VCC V Application Circuit AP170X GND RESET (RESET) VCC Microprocessor VCC GND RESET INPUT VCC
3-Pin Microprocessor Reset Circuits Anachip Corp. Function Description A microprocessor’s (µP’s) reset input starts the µP in a known state. The AP1701/2/3/4 assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions. They assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. The AP1701/2/3/4 have a push-pull output stage. Applications Information Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the AP1701/2/3/4 are relatively immune to short-duration negative-going VCC transients (glitches). The AP1701/2/3/4 do not generate a reset pulse. The graph was generated using a negative going pulse applied to VCC, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse width a negative going VCC transient can have without causing a reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, a VCC transient that goes 100mV below the reset threshold and lasts 20µs or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides additional transient immunity. Ensuring a Valid Reset Output Down to VCC = 0 RESET is guaranteed to be a logic low for VCC > 1V. Once VCC exceeds the reset threshold, an internal timer keeps RESET low for the reset timeout period; after this interval, RESET goes high. If a brownout condition occurs (VCC dips below the reset threshold), RESET goes low. Any time VCC goes below the reset threshold, the internal timer resets to zero, and RESET goes low. The internal timer starts after VCC returns above the reset threshold, and RESET remains low for the reset timeout period. When VCC falls below 1V, the AP1701/3 RESET output no longer sinks current—it becomes an open circuit. Therefore, hi gh-impedance CMOS logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applications since most µP and other circuitry is inoperative with VCC below 1V. However, in applications where RESET must be valid down to 0V, adding a pull down resistor to RESET causes any stray leakage currents to flow to ground, holding RESET low. R1’s value is not critical; 100k is large enough not to load RESET and small enough to pull RESET to ground. For the AP1702/4 if RESET is required to remain valid for VCC < 1V. Benefits of Highly Accurate Reset Threshold Most µP supervisor ICs have reset threshold voltages between 5% and 10% below the value of nominal sup-ply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted.
3-Pin Microprocessor Reset Circuits Anachip Corp. Function Block VREF Delay Circuit Driver RESET / RESET Performance Characteristics -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Iq Temp ( C ) Iq v.s Temp -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Threshold Temp 2.92 2.922 2.924 2.926 2.928 Threshold v.s. Temp
3-Pin Microprocessor Reset Circuits Anachip Corp. Timing Diagram Giltch Immunity 3000 900 270 140 90 70 58 50 50 48 480 500 1000 1500 2000 2500 3000 3500 0 100 200 300 400 500 600 700 800 900 1000 1100 RESET COMPARATOR OVERDRIVE(mV) Maximum Transient Duration(us) t1 t1 t1 t1 VCC VTH Active Low Active High
3-Pin Microprocessor Reset Circuits Anachip Corp. Marking Information 1 2 Year:0~9 Month: A~LIdentification code ( See appendix ) XX Y M X (Top View) SOT23-3L Blank: normal L: Lead Free Package Appendix Part Number Identification Code Part Number Identification Code AP1701A EA AP1703A EG AP1701B EB AP1703B EH AP1701C EC AP1703C EI AP1701D ED AP1703D EJ AP1701E EE AP1703E EK AP1701F EF AP1703F EL AP1702A E0 AP1704A E7 AP1702B E2 AP1704B E8 AP1702C E3 AP1704C E9 AP1702D E4 AP1704D EM AP1702E E5 AP1704E EN AP1702F E6 AP1704F EP
3-Pin Microprocessor Reset Circuits Anachip Corp. Package Information C L e E HE D A1b A Dimensions In Millimeters Dimensions In Inches Symbol A1 0.00 - 0.10 0.000 - 0.004 b 0.35 - 0.50 0.014 - 0.020 L 0.30 - 0.55 0.012 - 0.022