Datasheet

MAX6950/MAX6951
sequence is also reset, which might give rise to a one-
time display flicker when the register is written.
Selecting External Components R
SET
and C
SET
to Set Oscillator Frequency
and Segment Current
The RC oscillator uses an external resistor R
SET
and an
external capacitor C
SET
to set the oscillator frequency,
f
OSC
. The allowed range of f
OSC
is 1MHz to 8MHz.
R
SET
also sets the peak segment current. The recom-
mended values of R
SET
and C
SET
set the oscillator to
4MHz, which makes the blink frequencies 0.5Hz and
1Hz. The recommended value of R
SET
also sets the
peak current to 40mA, which makes the segment cur-
rent adjustable from 2.5mA to 37.5mA in 2.5mA steps.
I
SEG
= K
I
/ R
SET
mA
f
OSC
= K
F
/ (R
SET
✕
C
SET
+ C
STRAY
) MHz
Where:
K
I
= 2240
Serially Interfaced, +2.7V to +5.5V,
5- and 8-Digit LED Display Drivers
14 ______________________________________________________________________________________
Table 14. Decode-Mode Register Examples
REGISTER DATA
DECODE CODE
ADDRESS
CODE
(
HEX
)
D7 D6 D5 D4 D3 D2 D1 D0
HEX
CODE
No decode for digits 7–0 0x01 0 0 0 0 0 0 0 0 0x00
Hexadecimal decode for digit 0,
no decode for digits 7–1
0x01 0 0 0 0 0 0 0 1 0x01
Hexadecimal decode for digits
2–0, no decode for digits 7–3
0x01 0 0 0 0 0 1 1 1 0x07
Hexadecimal decode for digits
7–0
0x01 1 1 1 1 1 1 1 1 0xFF
Table 15. Hexadecimal Font
REGISTER DATA ON SEGMENTS = 1
7-SEGMENT
CHARACTER
D7* D 6 – D 4 D3 D2 D1 D0 dp* a b c d e f g
0 X 0000 1111110
1 X 0001 0110000
2 X 0010 1101101
3 X 0011 1111001
4 X 0100 0110011
5 X 0101 1011011
6 X 0110 1011111
7 X 0111 1110000
8 X 1000 1111111
9 X 1001 1111011
A X 1010 1110111
B X 1011 0011111
C X 1100 1001110
D X 1101 0111111
E X 1110 1001111
F X 1111 1000111
The decimal point segment is lit when bit D7 = 1.