Comments5 V TTL and CMOS Input and Output Voltage Levels(Figures from: http://www.allaboutcircuits.com/vol_4/chpt_3/10.html, visited 19APR2007)Comments- Noise Immunityo CMOS ___________ than TTL- Be careful mixing CMOS and TTL logic in the same circuit:o TTL CMOS: you will need to pull up TTL higho CMOS TTL: you may need a buffer to handle extra sinking current when CMOS output goes low BJ Furman | ME 106 Intro to Mechatronics | 5 V TTL and CMOS Input and Output Voltage Levels.doc | 19APR2007Page 1 of 4(Figure and table from: http://www.interfacebus.com/Speed-Power_Chart.html, visited 15APR04)Device Families:TTL (74xx) True TTL74L Low power74S Schottky74H High speed74LS Low power - Schottky 74AS Advanced - Schottky 74ALS Advanced - Low power - Schottky 74F(AST) Fast - (Advanced - Schottky) 74C CMOS...................check Vcc levels74HC (U) High speed - CMOS (Unbuffered output) 74HCT High speed - CMOS - TTL inputs 74AHC Advanced - High speed - CMOS 74AHCT Advanced - High speed - CMOS - TTL inputs74FCT (-A) Fast - CMOS - TTL inputs (speed variations)74FCT (-T, -AT) Fast - CMOS - TTL inputs (speed variations)74AC Advanced - CMOS 74ACT Advanced - CMOS - TTL inputs 74FACT AC, ACT (Q) series 74ACQ Advanced - CMOS - Quiet outputs 74ACTQ Advanced - CMOS - TTL inputs - Quiet outputsBJ Furman | ME 106 Intro to Mechatronics | 5 V TTL and CMOS Input and Output Voltage Levels.doc | 19APR2007Page 2 of 4(mW/gate)nanosecondsTTL Inverter (Totem Pole Output)(source: http://sub.allaboutcircuits.com/images/04073.png)TTL Buffer (Open-Collector Output)(source: http://sub.allaboutcircuits.com/images/04089.png)BJ Furman | ME 106 Intro to Mechatronics | 5 V TTL and CMOS Input and Output Voltage Levels.doc | 19APR2007Page 3 of 4CMOS Inverter(source: http://sub.allaboutcircuits.com/images/04132.png)(source: http://sub.allaboutcircuits.com/images/04133.png)(source: http://sub.allaboutcircuits.com/images/04134.png)BJ Furman | ME 106 Intro to Mechatronics | 5 V TTL and CMOS Input and Output Voltage Levels.doc | 19APR2007Page 4 of
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