逻辑十六进制显示屏
This hexadecimal display contains a four-bit latch, decoder, driver, and 4 × 7 light-emitting-diode LED character with two externally-driven decimal points in a 14-pin package. A description of the functions of the inputs of this device follows.
The LED driver outputs are designed to maintain a relatively constant on-level current of approximately 5 mA through each LED that forms the hexadecimal character. This current is virtually independent of the LED supply voltage within the recommended operating conditions. Drive current varies slightly with changes in logic supply voltage resulting in a change in luminous intensity as shown in Figure 2. This change willl not be noticeable to the eye. The decimal point anodes are connected to the LED supply; the cathodes are connected to external pins. Since there is no current limiting built into the decimal point circuits, this must be provided externally if the decimal points are used.
The resultant displays for the values of the binary data in the latches are as shown below.
## SOLID-STATE HEXADECIMAL DISPLAY WITH
INTEGRAL TTL CIRCUIT TO ACCEPT, STORE,
AND DISPLAY 4-BIT BINARY DATA