MAX6953 Maxim Integrated Products, MAX6953 Datasheet - Page 17

• Manufacturer Part Number: MAX6953
• Description: 2-Wire Interfaced/ 2.7V to 5.5V/ 4-Digit 5 x 7 Matrix LED Display Driver
• Manufacturer: Maxim Integrated Products

Table 18. User-Definable Font Pointer Base Address Table
The multiplexing scheme drives digits 0 and 1 at the
same time, then digits 2 and 3 at the same time. To
increase the effective brightness of the displays, drive
only two digits instead of four. By doing this, the aver-
age segment current doubles, but also doubles the
number of MAX6953s required to drive a given number
of digits.
Because digit 1 is driven at the same time as digit 0
(and digit 3 is driven at the same time as digit 2), only 1
bit is used to set the scan limit. The bit is clear if one or
two digits are to be driven, and set if three or four digits
are to be driven (Table 21).
Display brightness is controlled digitally by four pulse-
width modulators, one for each display digit. Each digit
is controlled by a nibble of one of the two intensity reg-
CHARACTER
RAM00
RAM01
RAM02
RAM03
RAM04
RAM05
RAM06
RAM07
RAM08
RAM09
RAM10
RAM11
RAM12
RAM13
RAM14
RAM15
RAM16
RAM17
RAM18
RAM19
RAM20
RAM21
RAM22
RAM23
FONT
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
______________________________________________________________________________________
CODE (HEX)
ADDRESS
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
0x05
Intensity Registers
DATA (HEX)
REGISTER
0xAD
0xBC
0xC1
0xC6
0xCB
0xD0
0xD5
0xDA
0xDF
0x8A
0x9E
0xA3
0xA8
0xB2
0xB7
0xE4
0xE9
0xEE
0x80
0x85
0x8F
0x94
0x99
0xF3
Matrix LED Display Driver
D7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
isters, Intensity10 and Intensity32. The modulator
scales the average segment current in 16 steps from a
maximum of 15/16 down to 1/16 of the peak current.
The minimum interdigit blanking time is therefore 1/16
of a cycle. The maximum duty cycle is 15/16 (Tables 23
and 24).
A write to the No-Op register is ignored.
The RC oscillator uses an external resistor R
external capacitor C
f
R
mended values of R
OSC
SET
Selecting External Components R
. The allowed range of f
D6
also sets the peak segment current. The recom-
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
C
SET
D5
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
0
0
0
0
0
1
1
1
1
to Set Oscillator Frequency and
REGISTER DATA
D4
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
1
1
1
1
0
0
0
1
SET
SET
to set the oscillator frequency,
and C
D3
0
0
1
1
0
1
1
0
1
1
0
0
1
0
0
1
0
0
1
1
0
1
1
0
OSC
SET
Segment Current
D2
0
1
0
1
1
0
1
0
0
1
0
1
1
0
1
0
0
1
0
1
1
0
1
0
No-Op Register
set the oscillator to
is 1MHz to 8MHz.
D1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
SET
SET
✕
and an
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
and
7
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