MAX7221EWG Maxim Integrated Products, MAX7221EWG Datasheet - Page 8

• Manufacturer Part Number: MAX7221EWG
• Description: LED Drivers
• Manufacturer: Maxim Integrated Products

Specifications of MAX7221EWG

• Number Of Digits: 8
• Number Of Segments: 64
• Low Level Output Current: 320 mA
• High Level Output Current: - 45 mA
• Operating Supply Voltage: 4 V to 5.5 V
• Maximum Supply Current: 330 mA
• Maximum Power Dissipation: 941 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-24 Wide
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Serially Interfaced, 8-Digit LED Display Drivers
Table 5. Code B Font
* The decimal point is set by bit D7 = 1
Table 6. No-Decode Mode Data Bits and
Corresponding Segment Lines
8
CHARACTER
7-SEGMENT
Corresponding
Segment Line
_______________________________________________________________________________________
blank
E
—
F
H
0
1
2
3
4
5
6
7
8
9
E
L
P
D
G
A
D7*
D7
DP
C
B
DP
D6
STANDARD 7-SEGMENT LED
D6–D4
A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
D5
B
REGISTER DATA
REGISTER DATA
D4
D3
C
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
D3
D
D2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
D2
E
D1
D1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
F
D0
G
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
DP*
The MAX7219/MAX7221 allow display brightness to be
controlled with an external resistor (R
between V+ and ISET. The peak current sourced from
the segment drivers is nominally 100 times the current
entering ISET. This resistor can either be fixed or vari-
able to allow brightness adjustment from the front
panel. Its minimum value should be 9.53kΩ, which typi-
cally sets the segment current at 40mA. Display bright-
ness can also be controlled digitally by using the
intensity register.
Digital control of display brightness is provided by an
internal pulse-width modulator, which is controlled by
the lower nibble of the intensity register. The modulator
scales the average segment current in 16 steps from a
maximum of 31/32 down to 1/32 of the peak current set
by R
intensity register format. The minimum interdigit blank-
ing time is set to 1/32 of a cycle.
SET
A
1
0
1
1
0
1
1
1
1
1
0
1
0
0
1
0
(15/16 to 1/16 on MAX7221). Table 7 lists the
B
1
1
1
1
1
0
0
1
1
1
0
0
1
0
1
0
ON SEGMENTS = 1
C
1
1
0
1
1
1
1
1
1
1
0
0
1
0
0
0
and Interdigit Blanking
D
1
0
1
1
0
1
1
0
1
1
0
1
0
1
0
0
Intensity Control
E
1
0
1
0
0
0
1
0
1
0
0
1
1
1
1
0
SET
) connected
F
1
0
0
0
1
1
1
0
1
1
0
1
1
1
1
0
G
0
0
1
1
1
1
1
0
1
1
1
1
1
0
1
0