TIL306, TIL307

NUMERIC DISPLAYS WITH LOGIC

SLBS001 – D1034, JUNE 1982 – REVISED SEPTEMBER 1992

POST OFFICE BOX 655303

3

description

These internally-driven seven-segment light-emitting-diode (LED) displays contain a BCD counter, a four-bit

latch, and a decoder/LED driver in a single 16-pin package. A description of the functions of the inputs and

outputs of these devices are in the terminal function table.

The TTL MSI circuits contain the equivalent of 86 gates on a single chip. Logic inputs and outputs are completely

TTL/DTL compatible. The buffered inputs are implemented with relatively large resistors in series with the bases

of the input transistors to lower drive-current requirements to one-half of that required for a standard Series

54/74 TTL input. The serial-carry input, actually two internal loads, is rated as one standard series 54/74 load.

of driving three standard Series 54/74 loads at a low logic level or six loads at a high logic level while the

maximum-count output is capable of driving five Series 54/74 loads at a low logic level or ten loads at a high

logic level. The RBO node with passive pull-up serves as a ripple-blanking output with the capability to drive

three Series 54/74 loads.

The LED driver outputs are designed specifically to maintain a relatively constant on-level current of

approximately 7 mA through each LED segment and decimal point. All inputs are diode clamped to minimize

transmission-line effects, thereby simplifying system design. Maximum clock frequency is typically 18 MHz and

power dissipation is typically 600 mW with all segments on.

The display format is as follows:

The displays may be interconnected to produce an n-digit display with the following features:

synchronous, multidigit counter systems with no external logic, minimizing total propagation delay from

the clock to the last latch output

with data being displayed