74LS47, 74LS47 Datasheet, 74LS47 pdf, buy 74LS47, 74LS47 BCD to 7- Segment Decoder. 74LS47 component details, pinout & Datasheet. 74LS47 is a BCD to 7-segment decoder/driver IC & It accepts a binary coded decimal as input and converts it. Texas Instruments 74LS47 Encoders, Decoders, Multiplexers & Demultiplexers are available at Mouser Electronics. Mouser offers inventory, pricing.
|Published (Last):||23 January 2011|
|PDF File Size:||16.10 Mb|
|ePub File Size:||17.22 Mb|
|Price:||Free* [*Free Regsitration Required]|
They have integral ripple-blanking facilities, but do not incorporate data latches. Series Using 7-Segment Displays All articles in this series: Method of modifying the Figure 17 circuit to give automatic leading-zero suppression. Learning Electronics Need to brush up on your electronics principles? These multi-part series may be just what you need! The IC does not incorporate a data latch and 74lx47 no facility for ripple blanking.
Figures 6, 774ps47 8 show how to modify the above circuit to drive LED common-anode displays, gas discharge displays, and low-brightness fluorescent displays, respectively. Figure 15 shows the basic circuit connections to be used when cascading stages. The LT terminal drives all display outputs on when the terminal is driven to logic 0 with the RBO terminal open or at logic 1. The rest of this article describes a few of 74ls477 most popular of these devices.
When the not-LATCH terminal is pulled low, the BCD input signals that are present at the moment of transition are latched into memory and fed in decoded form to the seven-segment outputs until the not-LATCH pin 74ls477 to the high state. Driving a gas discharge readout. Figure 1 shows the functional diagrams and pin designations of these devices, each of which is housed in a pin DIL package.
Method of applying leading-zero suppression to the first three digits of a four-digit display using 74LS47 ICs. Figure 3 shows how to connect the ripple-blanking terminals to give leading zero suppression on the first three digits of a four-digit display.
Way of using the B to drive a seven-segment LCD. Figure 4 shows the functional diagram and pin notations of the device, which can use any power source in the 5V to 15V range. Need to brush up on your electronics principles? Way of using the B to drive a common-cathode or b common-anode seven-segment LED displays. The opening episode of this special feature explained the basic operating and usage principles of seven-segment alphanumeric displays.
Finally, the LE latch enable terminal pin 5 enables the IC to give either direct or latched decoding operation. Basic way of using the B to drive a seven-segment common-cathode LED display. The B is very easy to use, and has only three input control terminals; of these, the not-LT pin 3 pin is normally tied high, but turns on all seven segments of the display when pulled low.
If cascaded B ICs are required to give automatic leading-zero suppression, the basic Figure 17 circuit must be modified as shown in Figure 18 to provide ripple-blanking operation. Note in the cases of Figures 6 and 7 that an NPN buffer transistor must be interposed between each output drive segment and the input segment of the display.
The 74LS47 has active-low outputs designed for driving a common-anode LED display via external current-limiting resistors Rxas shown in Figure 2.
Figure 5 shows the basic connections for driving a common-cathode LED display. The B has four input control terminals, and three auxiliary output terminals.
74LS47 – BCD to 7 Seg Dcdr Drvr Open Coll
Driving a gas discharge readout with a B. Enabling the display can be connected directly to the outputs of the IC without the 74lls47 of external current-limiting resistors. Figure 14 shows the functional diagram and pin notations of the B. Basic method of cascading B ICs without zero suppression. Figure 11 shows the basic way of using the B to drive 74os47 seven-segment LCD, and Figures 12 and 13 show it used to drive other types of seven-segment displays.
This procedure is repeated on all except the LSD, which does not require zero suppression. The B can be used to drive most popular types of seven-segment displays. This feature enables the IC to act as a universal unit that can drive common-cathode or common-anode LED or liquid-crystal seven-segment displays with equal ease, as shown in Figures 10 to The display can be blanked at any time by driving the BL terminal to the logic-1 level.
In practice, however, it is far better to use a B IC for this particular application.
74LS47 – BCD to 7 Seg Dcdr Drvr Open Coll
Driving a fluorescent readout with a B. Driving a low-brightness fluorescent readout. The not-BL pin 4 terminal is also normally tied high, but blanks turns off all seven segments when pulled low. A special two-part feature on how to use seven-segment alphanumeric displays.
The segment output currents are internally limited to about 5mA at 10V or 10mA at 15V. Functional diagram and pin notations of the B decade counter with seven-segment display driver.
Some of these devices have integral ripple-blanking facilities, others have built-in data latches, and a few even have built-in decade counter stages, etc.
In Figure 12Rx sets the segment current of the display and Ry sets the base current of the transistor 10mA maximum. The CO signal is a symmetrical square- wave at one-tenth of the CLK input frequency, and is useful in cascading B counters.
A current-limiting resistor Rx must be wired 74la47 series with each display segment and must have its value chosen to limit the segment current below 25mA. In each case, Rx determines the operating 74l47 current of the display, and Ry determines the base current of the transistor.
If trailing-zero suppression is required, the direction 74le47 ripple-blanking feedback must be reversed with the RBI terminal of the LSD grounded and its RBO terminal wired to the RBI terminal of the next least-significant stage, and so on.