74HC4543 Datasheet, PDF (2/11 Pages) NXP Semiconductors – BCD to 7-segment latch/decoder/driver for LCDs

Philips Semiconductors
BCD to 7-segment latch/decoder/driver
for LCDs
Product specification
74HC/HCT4543
FEATURES
• Latch storage of BCD inputs
• Blanking inputs
• Output capability: non-standard
• I_CC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT4543 are high-speed Si-gate CMOS
devices and are pin compatible with “4543” of the “4000B”
series. They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT4543 are BCD to 7-segment
latch/decoder/drivers for liquid crystal displays. They have
four address inputs (D₀ to D₃), an active HIGH latch
disable input (LD), an active HIGH blanking input (BI), an
active HIGH phase input (PH) and seven buffered
segment outputs (Q_a to Q_g).
The “4543” provides the function of a 4-bit storage latch
and an 8-4-2-1 BCD to 7-segment decoder driver. The
“4543” can invert the logic levels of the output combination.
The phase (PH), blanking (BI) and latch disable (LD)
inputs are used to reverse the function table phase, blank
the display and store a BCD code, respectively.
For liquid crystal displays a square-wave is applied to PH
and the electrical common back-plane of the display. The
outputs of the “4543” are directly connected to the
segments of the liquid crystal.
QUICK REFERENCE DATA
GND = 0 V; T_amb = 25 °C; t_r = t_f = 6 ns
SYMBOL
PARAMETER
CONDITIONS
t_PHL/ t_PLH
C_I
C_PD
propagation delay
D_n to Q_n
LD to Q_n
BI to Q_n
input capacitance
power dissipation capacitance per package
C_L = 15 pF; V_CC = 5 V
notes 1 and 2
Notes
1. C_PD is used to determine the dynamic power dissipation (P_D in µW):
P_D = C_PD × V_CC2 × f_i + ∑ (C_L × V_CC2 × f_o) where:
f_i = input frequency in MHz
f_o = output frequency in MHz
∑ (C_L × V_CC2 × f_o) = sum of outputs
C_L = output load capacitance in pF
V_CC = supply voltage in V
2. For HC the condition is V_I = GND to V_CC
For HCT the condition is V_I = GND to V_CC −1.5 V
TYPICAL
HC
HCT
UNIT
29
33
ns
32
31
ns
20
28
ns
3.5
3.5
pF
42
42
pF
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
December 1990
2