MC74HC4511
High–Speed CMOS Logic Data
DL129 — Rev 6 5 MOTOROLA
FUNCTION TABLE
Inputs Outputs
LE BI LT D C B A a b c d e f g Display
X X L X X X X H H H H H H H 8
X L H X X X X L L L L L L L Blank
L H H L L L L H H H H H H L 0
L H H L L L H L H H L L L L 1
L H H L L H L H H L H H L H 2
L H H L L H H H H H H L L H 3
L H H L H L L L H H L L H H 4
L H H L H L H H L H H L H H 5
L H H L H H L L L H H H H H 6
L H H L H H H H H H L L L L 7
L H H H L L L H H H H H H H 8
L H H H L L H H H H L L H H 9
L H H H L H L L L L L L L L Blank
L H H H L H H L L L L L L L Blank
L H H H H L L L L L L L L L Blank
L H H H H L H L L L L L L L Blank
L H H H H H L L L L L L L L Blank
L H H H H H H L L L L L L L Blank
H H H X X X X * *
*= Depends upon the BCD code previously applied while LE was at a low level.
PIN DESCRIPTIONS
INPUTS
A, B, C, D (Pins 7, 1, 2, 6)
BCD inputs. A (pin 7) is the least significant bit and D (pin
6) is the most significant bit. Hexadecimal code A–F at these
inputs causes the outputs to assume a low level, offering an
alternate method of blanking the display.
OUTPUTS
a, b, c, d, e, f, g (Pins 13, 12, 11, 10, 9, 15, 14)
Decoded, buffered seven–segment display–driver out-
puts. These outputs, unlike the MC14511, have CMOS driv-
ers, which produce typical CMOS output voltage levels.
These outputs are connected to various displays as shown in
Figure 7.
CONTROL INPUTS
BI (Pin 4)
Active–low display blanking input. A low level on this input
will cause all outputs to be held low , thereby blanking the dis-
play. LT is the only input that overrides the BI input.
LT (Pin 3)
Active–low lamp test. A low level on this input causes all
outputs to assume a high level. This input allows the user to
test all segments of a display with a single control input. This
input is independent of all other inputs.
LE (Pin 5)
Latch enable input. This input controls the 4–bit transpar-
ent latch. A high level on this input latches the code present
at the A, B, C and D inputs, a low level allows the code to be
transmitted through the latch to the decoder.