MAX7221EWG Maxim Integrated Products, MAX7221EWG Datasheet - Page 7

• 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

Table 2. Register Address Map
Table 3. Shutdown Register Format (Address (Hex) = 0xXC)
Table 4. Decode-Mode Register Examples (Address (Hex) = 0xX9)
Shutdown
Mode
Normal
Operation
No-Op
Digit 0
Digit 1
Digit 2
Digit 3
Digit 4
Digit 5
Digit 6
Digit 7
Decode
Mode
Intensity
Scan Limit
Shutdown
Display
Test
No decode for digits 7–0
Code B decode for digit 0
No decode for digits 7–1
Code B decode for digits 3–0
No decode for digits 7–4
Code B decode for digits 7–0
REGISTER
Serially Interfaced, 8-Digit LED Display Drivers
MODE
DECODE MODE
D15–
D12
_______________________________________________________________________________________
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ADDRESS CODE
D11
(HEX)
0xXC
0xXC
0
0
0
0
0
0
0
0
1
1
1
1
1
1
ADDRESS
D10
0
0
0
0
1
1
1
1
0
0
0
0
1
1
D7
0
0
0
1
D9
0
0
1
1
0
0
1
1
0
0
1
1
0
1
D7
X
X
D8
0
1
0
1
0
1
0
1
0
1
0
1
0
1
D6
0
0
0
1
CODE
0xXA
0xXB
0xXC
0xX0
0xX1
0xX2
0xX3
0xX4
0xX5
0xX6
0xX7
0xX8
0xX9
0xXF
HEX
D6
X
X
D5
0
0
0
1
D5
X
X
On initial power-up, all control registers are reset, the
display is blanked, and the MAX7219/MAX7221 enter
shutdown mode. Program the display driver prior to
display use. Otherwise, it will initially be set to scan one
digit, it will not decode data in the data registers, and
the intensity register will be set to its minimum value.
The decode-mode register sets BCD code B (0-9, E, H,
L, P, and -) or no-decode operation for each digit. Each
bit in the register corresponds to one digit. A logic high
selects code B decoding while logic low bypasses the
decoder. Examples of the decode mode control-regis-
ter format are shown in Table 4.
When the code B decode mode is used, the decoder
looks only at the lower nibble of the data in the digit
registers (D3–D0), disregarding bits D4–D6. D7, which
sets the decimal point (SEG DP), is independent of the
decoder and is positive logic (D7 = 1 turns the decimal
point on). Table 5 lists the code B font.
When no-decode is selected, data bits D7–D0 corre-
spond to the segment lines of the MAX7219/MAX7221.
Table 6 shows the one-to-one pairing of each data bit
to the appropriate segment line.
REGISTER DATA
D4
0
0
0
1
REGISTER DATA
D4
X
X
D3
0
0
1
1
D3
X
X
D2
0
0
1
1
Decode-Mode Register
D2
D1
X
X
0
0
1
1
Initial Power-Up
D0
0
1
1
1
D1
X
X
CODE
HEX
0x00
0x01
0x0F
0xFF
D0
0
1
7