ICM7228 Datasheet, PDF (7/17 Pages) Intersil Corporation – 8-Digit, Microprocessor- Compatible, LED Display Decoder Driver

ICM7228
Timing Diagrams
MODE
WRITE
INPUT
DATA
t_MS
t_MH
t_WL
t_WH
t_DS
t_DH
VALID
FIGURE 1. ICM7228A/B WRITE CYCLE
MODE
WRITE
(D1)
CONTROL WORD
WRITE DATA
8 PULSES
TYPE OF DECODER?ID6
DECODE/NO DECODE? ID5
SHUTDOWN?ID4
DATA COMING ID7
(D8) ^{DON’T CARE}
CONTROL WORD
TYPE OF DECODER?ID6
DECODE/NO DECODE? ID5
SHUTDOWN? ID4
DATA COMING ID7
FIGURE 2. ICM7228A/B SEQUENTIAL 8-DIGIT RAM UPDATE
DIGIT
ADDRESS
DAO-DAZ
WRITE
DATA
VALID
t_AS
t_WL
t_DS
t_AH
t_WH
t_DH
VALID DATA
FIGURE 3. ICM7228C/D WRITE CYCLE
INTERDIGIT BLANKING
INTERNAL SIGNAL
D2
D5
D1
D7
TYPICAL DIGITS ^D8
OUTPUT PULSES _D6
D4
D3
10µs (TYP)
FREE RUNNING
320µs (TYP)
FREE RUNNING (PER DIGIT)
INTERDIGIT BLANKING
FIGURE 4. DISPLAY DIGITS MULTIPLEX (COMMON ANODE DISPLAY)
Typical Performance Curves
-55^oC
0
25^oC
125^oC
100
200
80
125^oC
25^oC
300
60
400
40
-55^oC
25^oC
125^oC
500
-55^oC
5.0
4.0
3.0
2.0
1.0
0
V_DD-V_DIG (V)
FIGURE 5. COMMON ANODE DIGIT DRIVER I_DIG vs (V_DD - V_DIG)
20
0
0
1.0
2.0
3.0
4.0
5.0
V_SEG (V)
FIGURE 6. COMMON ANODE SEGMENT DRIVER I_SEG vs V_SEG
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