System Reset PST574 MITSUMI System Reset Monolithic IC PST574 Outline This IC functions in a variety of CPU systems and other logic systems, to detect power supply voltage and reset the system accurately when power is turned on or interrupted. This ultra-low current consumption low reset type system reset IC has a built-in fixed delay time generating circuit. It is ideal for use in multi-CPU systems because a fast-rising output waveform can be obtained. Features 1. 2. 3. 4. 5. Ultra-low current consumption Low operating limit voltage Output current high for ON Hysteresis voltage provided in detection voltage Built-in delay circuit with excellent delay time temperature characteristics 6. 10 ranks of detection voltage ICCH=7.5µA typ. ICCL=400µA typ. 0.65V typ. 30mA typ. 50mV typ. 50mV typ. PST574 C : 4.5V typ. D : 4.2V typ. E : 3.9V typ. F : 3.6V typ. G : 3.3V typ. H : 3.1V typ. I : 2.9V typ. J : 2.7V typ. K : 2.5V typ. L : 2.3V typ. Package MMP-3A (PST574 M) TO-92A (PST574 ) contains detection voltage rank . * Applications 1. 2. 3. 4. 5. Reset circuits in microcomputers, CPUs and MPUs (especially multi-CPU sets) Logic circuit reset circuits. Battery voltage check circuits. Back-up power supply switching circuits. Level detection circuits. Pin Assignment 1 2 3 TO-92A 1 VCC 2 GND 3 VOUT 1 3 2 MMP-3A 1 VCC 2 GND 3 VOUT System Reset PST574 MITSUMI Equivalent Circuit Diagram Absolute Maximum Ratings Item Symbol Rating Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+75 °C Power supply voltage VCC max. -0.3~10 V Allowable loss Pd Electrical Characteristics Item Detection voltage Hysteresis voltage Detection voltage temperature coefficient Low-level output voltage Output leakage current Circuit current while on Circuit current while off "H"transport delay time "L"transport delay time Operation limit voltage Output current while on I Output current while on II 1 : tpLH : VCC=(VS typ.-0.4V) 2 : VCC=VS min.-0.15V * * (Ta=25°C) 200 (MMP-3A) 300 (TO-92A) mW (Ta=25°C) (Except where noted otherwise, resistance unit is Ω) Symbol VS VS Measurement Measurement conditions circuit PST574C PST574D PST574E PST574F RL=470 PST574G 1 VOL <= 0.4V PST574H VCC=H L PST574I PST574J PST574K PST574L 1 RL=470, VCC=L H L Min. Typ. Max. Units 4.3 4.0 3.7 3.4 3.1 2.9 2.75 2.55 2.35 2.15 25 4.5 4.2 3.9 3.6 3.3 3.1 2.90 2.70 2.50 2.30 50 VS/ T 1 RL=470, Ta=-20°C~+75°C ±0.01 VOL IOH ICCL ICCH tpLH tpHL VopL IOL I IOL II 1 1 1 1 2 2 1 1 1 VCC=VS min.-0.05V, RL=470 VCC=7.5V VCC=VS min.-0.05V, RL=∞ VCC=VS typ./0.85V, RL=∞ 1 RL=4.7kΩ, CL=100pF 1 RL=4.7kΩ, CL=100pF RL=4.7kΩ, VOL =< 0.4V VCC=Vs min.-0.05V, RL=0 2 Ta=-20°C~+75°C, RL=0 0.1 * * * (VS typ.+0.4V), tpHL : VCC=(VS typ.+0.4V) 250 8 5 (VS typ.-0.4V) 400 7.5 400 6 0.65 30 4.7 4.4 4.1 3.8 3.5 3.3 3.05 2.85 2.65 2.45 100 V mV %/°C 0.4 ±0.1 650 12.0 600 20 0.85 V µA µA µA µS µS V mA mA System Reset PST574 MITSUMI Measuring Circuit [1] [2] 0.8V 4.9 VS 4.1 0V Note: Input model is an example for PST574C. Characteristics (Example: PST574C) Vcc vs. Icc Vcc vs. VOUT 500 8 7 Ta=-20°C 400 6 5 Ta=25°C VOUT (V) 4 ICC (µA) 3 Ta=-25°C Ta=25°C Ta=75°C 2 1 0 1 2 3 300 Ta=75°C 200 4 5 6 7 8 100 VCC (V) 0 0 1 2 3 4 5 6 7 8 VCC (V) Vs vs. Ta Vs vs. Ta 4.53 80 4.52 70 4.51 60 VS 4.50 (V) VS 50 (mV) 4.49 40 4.48 30 4.47 20 -40 -20 0 20 40 Ta (°C) 60 80 -40 -20 0 20 Ta (°C) 40 60 80 System Reset PST574 MITSUMI IoL vs. Ta VoL vs. Ta 60 300 50 250 IOL 40 (mA) VOL 200 (mV) 30 150 20 100 10 50 -40 -20 0 20 40 60 -40 80 -20 0 20 Ta (°C) 40 60 80 40 60 80 Ta (°C) ICCH vs. Ta ICCL vs. Ta 10 500 9 8 lCCH (µA) ICCL 400 (µA) 7 6 300 5 4 -40 -20 0 20 40 60 -40 80 -20 0 20 Ta (°C) Ta (°C) tPLH vs. Ta Pd vs. Ta 600 300 500 450 tPLH (µS) 200 Pd (mW) 400 350 100 300 250 -40 -20 0 20 40 60 0 80 0 25 50 Ta (°C) 75 Ta (°C) Timing Chart VCC /VOUT (V) 7 6 5 4 3 2 1 0 VCC VS VOUT Time RESET ON OFF Undefined 100 125 MITSUMI System Reset PST574 Application circuits 1. Normal hard reset Note: Connect a capacitor between IC pins 1 and 2 if VCC line impedance is high. 2. Battery checker (LED ON for high voltage) Note: Connect a capacitor between IC pins 1 and 2 if VCC line impedance is high. 3. Battery checker (LED ON for low voltage) Note: Connect a capacitor between IC pins 1 and 2 if VCC line impedance is high. 4. Hysteresis voltage UP method When increasing hysteresis voltage for stable system operation, determine RH as follows and connect externally. However, ICCH is -5000PPM/°C, so perform temperature compensation at RH when using over a wide temperature range. Hysteresis voltage UP amount ( Vsup) is Vsup .=. RH ICCL Total hysteresis voltage ( Vstotal) is Vstotal .=. Vs + Vsup (Operation will be destabilized if RH is raised too much.) Note: Connect a capacitor between IC pins 1 and 2 if VCC line impedance is high.