ICM7243_05 Datasheet, PDF (6/14 Pages) Intersil Corporation – 8-Character, Microprocessor-Compatible, LED Display Decoder Driver

ICM7243
Performance Curves
30
V_DD = 5.5V
20
5.0V
10
4.5V
0
0
1
2
3
SEGMENT VOLTAGE (V)
FIGURE 4. SEGMENT CURRENT vs OUTPUT VOLTAGE
500
V_DD = 5.5V
400
300
5.0V
200
100
4.5V
0
1
2
3
SEGMENT VOLTAGE (V)
FIGURE 5. CHARACTER CURRENT vs OUPUT VOLTAGE
Pin Descriptions
SIGNAL
PIN
FUNCTION
ICM7243A(B)
D0 - D5
10 - 15
(8 - 13)
Six-Bit ASCll Data input pins (active high).
CS, CS
16
(14 - 16)
Chip Select from µP address decoder, etc.
WR
17
WRite pulse input pin (active low). For an active high write pulse, CS can be used, and WR can be used
as CS.
MODE
31
Selects data entry MODE. High selects Sequential Access (SA) mode where first entry is displayed in
“leftmost” character and subsequent entries appear to the “right”. Low selects the Random Access
(RA) mode where data is displayed on the character addressed via A0 - A2 Address pins.
A0/SEN
30
In RA mode it is the LSB of the character Address. In SA mode it is used for cascading devices for
displays of more than 8 characters (active high enables device controller).
A1/CLeaR
29
In RA mode this is the second bit of the address. In SA mode, a low input will CLeaR the Serial Address
Counter, the Data Memory and the display.
A2/DISPlay FULL
28
In RA mode this is the MSB of the Address. In SA mode, the output goes high after eight entries,
indicating DISPlay FULL.
OSC/OFF
27
OSCillator input pin. Adding capacitance to V_DD will lower the internal oscillator frequency. An external
oscillator can be applied to this pin. A low at this input sets the device into a (shutdown) mode, shutting
OFF the display and oscillator but retaining data stored in memory.
SEG a - SEG m, 2 - 9, 32 - 40 SEGment driver outputs.
DP
(2 - 7), (32 - 40)
CHARacter 1 - 8
18 - 21,
23 - 26
CHARacter driver outputs.
6
FN3162.3
October 28, 2005