Order Number DM54LSJ, DM54LSW, DM74LSWM or DM74LSN. See Package Number J20A, M20B, N20A or W20A 2. Download Fairchild Semiconductor DM74LSN pdf datasheet file. DM74LSN Octal D-type Transparent Latches And Edge-triggered Flip-flops DM74LS Details, datasheet, quote on part number: DM74LSN.

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The digital signal is finally staticized by U7, 74LS If the signal is more positive than this level, the output will switch low and if more negative, it will switch high. These capacitors are identified on the data board and in the schematic as C through C This fm74ls374n reduce the gain.

These are wired back datasbeet back between the two ground levels. Before each integration commences, the switch is closed to discharge the integration capacitor, C2. There is a separate regulator for the digital Vcc, U The digitiser data board was designed, developed, fabricated and tested by the author.

The works reference is:. The two unused controls are pulled high by resistors R1 and R2. To describe the operation of the circuit, channel 1 is used as an example. This IC is a quad programmable comparator selected for its low and repeatable dm74ls37n offset voltages. All digital grounds satasheet linked to this plane. Refer to the complete schematic diagram at the end of this section. The signal fed onto the edge connector is passed directly through the high pass filter.


This documentation concerns the 64 channel Digitiser Data Boards designed in Each comparator package is decoupled from both power rails by 10nF capacitors. It is a modification datashfet a previous design of The signal is passed through a 0.

Stock/Availability for: DM74LSO2N

There are nine data boards in the crate supplied, thus allowing up to channels to be digitised. During operation there is a potential of ddatasheet or less between these two lines. These boards are controlled by one Control Board in the same crate.

The typical current requirements are:. This comprises a 2M resistor package RA1A, and 0. This is made up of a network of tracks over the board.

This is to supplement an incomplete track. Nearby C, there are two diodes D1, and D2. This was required due to the obsolescence of the comparators previously used.

Secondly, the dm74ls3774n pads adjacent to the Datazheet packages allow for the addition of a capacitor in parallel to the internal pF. The output of the comparator is open collector and is thus virtually isolated from the input terminals. BANK – signal common to each of the data boards from the control board – pulses low for a period determined by data transfer rate of control board, and changes at twice the rate of FINGER.

The integration period is determined by the separate control board.

There is considerable decoupling throughout the board. The shielding dstasheet provided by the partial groundplane on the component side of the board. Failure to do this could result in data bus contention. The sign of the output of the integrator is detected by a comparator, the output of which is written onto one bit of a 64 bit data register comprising a D-type latch.


DM74LSN/A+ Datasheet – Flip-Flop from National Semiconductor

Test Switches There are two switches on the board selected by jumpers. The function of this filter is to block DC signals and to control the overall sensitivity of the integrator. Dm7l4s374n testing the data boards out of the crate, it is important to put these switches back to the ‘Normal’ settings, as illustrated in figure 2 below, before reinserting into the crate.

Following manufacturers’ guidelines, each ACF integrator is decoupled from both rails by 1.

This is an octal D-type flip flop with tri-state outputs. They are provided to facilitate board testing. The operation is identical for all 64 channels. Manufacturers of the board were Precision Engineering Products Chesterton Ltd, who will retain the production artwork for a limited time. An integration is then performed across a precision pF dm74ls37n4 for a single sample interval.

DM74LS374N 数据手册 ( 数据表 ) – Fairchild Semiconductor

When the operation is complete, the switch is closed for 2us, discharging the capacitor. Full circuit details and user instructions for the control board are in a separate document. This reads data from each board and writes the data to a computer dafasheet along with a count word.