mc14489 Freescale Semiconductor, Inc, mc14489 Datasheet - Page 10

• Manufacturer Part Number: mc14489
• Description: Multi-character Display/lamp Driver
• Manufacturer: Freescale Semiconductor, Inc

MC14489
10
NOTE: ENABLE (which initially must be inactive high) is kept active–low during the entire 4–byte configuration transfer or 6–byte display
D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11
transfer. When ENABLE is brought back high, either a 4– or 6–byte transfer occurs in the cascaded devices, depending on the number
of bytes in the transfer.
DIMMER
h BITS
AND
BIT
C7
SHIFTED IN
1ST BYTE
Figure 9. a through h Nominal Current per Output versus Rx
NOTE: Drive current tolerance is approximately 15%.
Figure 8. Bit Stream Formats for Two Devices Cascaded
C6
NIBBLE
CONFIGURATION
BANK
15
20
35
30
25
10
REGISTER OF
5
SHIFTED IN
DEVICE 2 IN
5
400
1ST BYTE
FIGURE 11
DISPLAY REGISTER OF DEVICE 2
C5
800
NIBBLE
BANK
C4
4
2ND BYTE
IN FIGURE 11
1.2 k
(a) Configuration Registers
C3
NIBBLE
BANK
WITH D23 = LOW, i OH IS CUT BY 50%.
DON’T CARE
3
(b) Display Registers
BIT D23 = HIGH (BRIGHTEN LEDs)
Rx, EXTERNAL RESISTOR ( )
1.6 k
2ND BYTE
C2
NIBBLE
BANK
2.0 k
C1
2
5 V SUPPLY
3RD BYTE
D10 D9
C0
2.4 k 2.8 k
NIBBLE
BANK
DON’T CARE
1
3RD BYTE
D8
DIMMER
h BITS
AND
3.2 k
BIT
4TH BYTE
D7
NIBBLE
3.6 k
D6
CONFIGURATION
BANK
REGISTER OF
DISPLAY REGISTER OF DEVICE 1
DEVICE 1 IN
5
FIGURE 11
4TH BYTE
D5
4.0 k
NIBBLE
BANK
IN FIGURE 11
D4
4
5TH BYTE
D3
NIBBLE
BANK
3
D2
NIBBLE
D1
BANK
6TH BYTE
2
MOTOROLA
D0
NIBBLE
BANK
1