HD74AC

The HD74AC circuit shown in Figure 9 was used to compare the power consumption of FACT versus ALS devices.Two identical circuits were built on the same board and driven from the same input.  In the circuit, the input signal was driven into four D-type flip-flops which act as divide-by-2 frequency dividers.  The outputs from the flip-flops were connected to the inputs of a HD74AC138/74ALS138 decoder.  This generated eight non-overlapping clock pulses on the outputs of the HD74AC138/74ALS138, which were then connected to an HD74AC04/74ALS04 inverter.  The input frequency was then varied and the power consumption was measured.  Figure 10 illustrates the results of these measurements.

Features of the HD74AC are:(1)Full logic product line; (2)Industry standard functions and pinouts for SSI and MSI; (3)Meets or exceeds JEDEC standards for HD74ACXX family; (4)TTL inputs on selected circuits; (5)High performance outputs:Common output structure for standard and buffer drivers;Output Sink/Source Current of 24 mA;Transmission line driving 50 ? guaranteed; (6)Operation from 2 to 6 volts guaranteed; (7)Temperature range 40°C to +85°C; (8)Improved ESD protection network; (9)High current latch-up immunity.

The absolute maximum ratings of the HD74AC can be summarized as:(1)Supply voltage: 0.5 to 7.0 V; (2)DC input Diode current or DC input voltage:20 mA ;20 mA( VI= VCC +0.5)p;0.5 to VCC +0.5 V.; (3)DC output Diode current or DC output voltage:50 mA (VO = 0.5);50 mA (VO = VCC +0.5);0.5 to VCC +0.5 V; (4)DC output source or sink current:±50 mA; (5)DC VCC or ground current per output pin:±50 mA; (6)Storage temperature: 65 to 150 °C.If you want to know more information such as the electrical characteristics, please download the datasheet in www.seekic.com or www.chinaicmart.com.