MAX6954AAX-T Maxim Integrated Products, MAX6954AAX-T Datasheet - Page 10

• Manufacturer Part Number: MAX6954AAX-T
• Description: LED Drivers 7-, 14-, 16-Segment LED Display Driver,
• Manufacturer: Maxim Integrated Products

Specifications of MAX6954AAX-T

• Number Of Digits: 16
• Number Of Segments: 128
• Low Level Output Current: 935000 uA
• High Level Output Current: 55000 uA
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Supply Current: 30000 uA
• Maximum Power Dissipation: 941 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SSOP-36
• Minimum Operating Temperature: - 40 C

4-Wire Interfaced, 2.7V to 5.5V LED Display
Driver with I/O Expander and Key Scan
The most significant bit of the register data (D7) con-
trols the DP segment of the digits; it is set to 1 to light
DP, and to zero to leave DP unlit (Table 9).
For 7-segment displays, the digit plane data register
can be used to address a character generator, which
contains the data of a 16-character font containing the
hexadecimal font. The decode mode register can be
used to disable the character generator and allow the
segments to be controlled directly. Table 10 shows the
one-to-one pairing of each data bit to the appropriate
segment line in the digit plane data registers. The hexa-
decimal font is decoded according to Table 11.
The digit-type register configures the display driver for
various combinations of 14-segment digits, 16-segment
digits, and/or pairs, or 7-segment digits. The function of
this register is to select the appropriate font for each
digit and route the output of the font to the appropriate
MAX6954 driver output pins. The MAX6954 has four
digit drive slots. A slot can be filled with various combi-
nations of monocolor and bicolor 16-segment displays,
14-segment displays, or two 7-segment displays. Each
pair of bits in the register corresponds to one of the four
Figure 4. Transmission of 16 Bits to the MAX6954
Figure 5. Transmission of More than 16 Bits to the MAX6954
10
DOUT
CLK
DOUT
DIN
CS
CLK
DIN
CS
______________________________________________________________________________________
BIT
D15
1
BIT
2
D14
N-15
D13
N-31
N-14
N-30
D12
N-13
N-29
D11
N-12
N-28
D10
N-11
N-27
D9
N-10
N-26
D8
N-9
N-25
digit drive slots, as shown in Table 12. Each bit also cor-
responds to one of the eight common-cathode digit
drive outputs, CC0 to CC7. When using bicolor digits,
the anode connections for the two digits within a slot are
always the same. This means that a slot correctly drives
two monocolor or one bicolor 14- or 16-segment digit.
The digit type register can be written, but cannot be
read. Examples of configuration settings required for
some display digit combinations are shown in Table 13.
In 7-segment mode, the hexadecimal font can be dis-
abled (Table 14). The decode-mode register selects
between hexadecimal code or direct control for each of
eight possible pairs of 7-segment digits. Each bit in the
register corresponds to one pair of digits. The digit
pairs are {digit 0, digit 0a} through {digit 7, digit 7a}.
Disabling decode mode allows direct control of the 16
LEDs of a dual 7-segment display. Direct control mode
can also be used to drive a matrix of 128 discrete
LEDs.
D7
N-8
N-24
N-7
N-23
D6
N-22
N-6
7-Segment Decode-Mode Register
D5
N-21
N-5
D4
N-20
N-4
D3
N-19
N-3
D2
N-18
N-2
D1
N-17
N-1
D0
N-16
N
N-15
D15 = 0