Rainbow Electronics MAX6959 - Manual (Page 5)

Detailed Description
The MAX6958/MAX6959 serially interfaced display dri-
vers drive up to: four 7-segment digits plus four dis-
crete LEDs if the decimal points are used, or four
7-segment digits plus eight discrete LEDs if the deci-
mal points are not used, or 36 discrete LEDs. Table 1
lists the display connection scheme.
The MAX6958/MAX6959 include the hexadecimal font
map for seven-segment displays. The seven-segment
LED digits can be controlled directly or programmed to
use the hexadecimal font. Direct segment control
allows the MAX6958/MAX6959 to drive bar graphs and
discrete LED indicators.
The MAX6958/MAX6959 use a multiplexing scheme that
minimizes the connections between the driver and LED
display. The MAX6958/MAX6959 can drive monocolor
and bicolor single-digit type displays, and monocolor
dual-digit displays. Dual-digit displays internally
wire together the equivalent segments for each digit,
requiring only eight segment pins instead of 16. The
MAX6958/MAX6959 can also drive multidigit LED dis-
plays that have the segments individually pinned for
each digit.
To connect four single-digit displays to the MAX6958/
MAX6959, connect cathode outputs DIG0/SEG0–
DIG3/SEG3 to the cathodes of the four display digits as
shown in Table 1 (CC0–CC3). Drive eight additional
LEDs with SEG0 to SEG7. Four of the eight LEDs can
be the decimal point (DP) segments of the four dis-
plays, and the other four can be discrete LED indica-
tors.
To connect two dual-digit displays to the MAX6958/
MAX6959, connect cathode outputs DIG0/SEG0 and
DIG1/SEG1 to the cathodes of the first dual digit.
Connect DIG2/SEG2 and DIG3/SEG3 to the cathodes
of the second dual digit. SEG0 to SEG3 can only drive
discrete LEDs, not digit DP segments. SEG4 to SEG7
can drive the DP segments if required. Bicolor single-
digit displays are connected and treated as dual-digit
displays, each digit being one of the two colors.
MAX6958/MAX6959
2-Wire Interfaced, 3V to 5.5V, 4-Digit,
9-Segment LED Display Drivers with Keyscan
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Pin Description
PIN
MAX6958 MAX6959
NAME FUNCTION
1 1 SDA Serial Data I/O
2 2 SCL Serial Clock Input
3 — SEG9 Segment Output. Segment driver sourcing current to a display anode.
— 3 IRQ/SEG9
Interrupt or Segment Output. May be segment driver sourcing current to a display
anode, or open-drain interrupt output, or open-drain logic output.
4–7, 11–15 4–7, 11–15 DIGX, SEGX
Digit and Segment Drivers. Digit X outputs sink current from the display common
cathode when acting as digit drivers. Segment X drivers source current to the display
anodes. Segment/digit drivers are high impedance when turned off.
8 8 GND Ground
9, 10 — N.C. No Connect. Connect to V+ or leave open.
— 9 INPUT1
General-Purpose Input Port 1 with Internal Pullup. May be configured as general-
purpose logic input or keyscan input. Connect to V+ or leave open if unused.
— 10 INPUT2
General-Purpose Input Port 2 with Internal Pullup. May be configured as general-
purpose logic input or keyscan input. Connect to V+ or leave open if unused.
16 16 V+ Positive Supply Voltage
DIG0/SEG0 DIG1/SEG1 DIG2/SEG2 DIG3/SEG3 SEG 4 SEG 5 SEG 6 SEG 7 SEG 8 SEG 9/IRQ
LED Digit 0 CC0 SEG 0 SEG g SEG f SEG e SEG d SEG c SEG b SEG a SEG 4
LED Digit 1 SEG 1 CC1 SEG g SEG f SEG e SEG d SEG c SEG b SEG a SEG 5
LED Digit 2 SEG g SEG f CC2 SEG 2 SEG e SEG d SEG c SEG b SEG a SEG 6
LED Digit 3 SEG g SEG f SEG 3 CC3 SEG e SEG d SEG c SEG b SEG a SEG 7
Table 1. Standard Driver Connection to LED Displays