MAX6957ANI+ Maxim Integrated Products, MAX6957ANI+ Datasheet - Page 5

• Manufacturer Part Number: MAX6957ANI+
• Description: IC DRIVER LED PORT 20/28 28-DIP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6957ANI+

• Display Type: LED
• Configuration: 7, 16, 20 Segment
• Interface: 4-Wire Serial
• Current - Supply: 180µA
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 28-DIP (0.300", 7.62mm)
• Number Of Segments: 28
• Low Level Output Current: 18000 uA
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Supply Current: 270 uA
• Maximum Power Dissipation: 1143 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Digits Or Characters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX6957 LED driver/GPIO peripheral provides up
to 28 I/O ports, P4 to P31, controlled through an SPI-
compatible serial interface. The ports can be config-
ured to any combination of constant-current LED
drivers, logic inputs and logic outputs, and default to
logic inputs on power-up. When fully configured as an
LED driver, the MAX6957 controls up to 28 LED seg-
ments with individual 16-step adjustment of the con-
stant current through each LED segment. A single
resistor sets the maximum segment current for all seg-
ments, with a maximum of 24mA per segment. The
MAX6957 drives any combination of discrete LEDs and
CA digits, including seven-segment and starburst
alphanumeric types.
Figure 1 is the MAX6957 functional diagram. Any I/O
port can be configured as a push-pull output (sinking
10mA, sourcing 4.5mA), or a Schmitt-trigger logic
input. Each input has an individually selectable internal
pullup resistor. Additionally, transition detection allows
seven ports (P24 through P30) to be monitored in any
maskable combination for changes in their logic status.
28 SSOP
28 DIP
5–24
2, 3
25
26
27
28
—
—
—
1
4
28-Port LED Display Driver and I/O Expander
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
PIN
SSOP
5–32
2, 3
36
33
34
35
36
—
—
—
1
4
_______________________________________________________________________________________
Detailed Description
37, 38,
11, 20,
12–19,
TQFN
21–30
1–10,
EP
40
36
39
40
32
33
34
35
31
—
P12–P31
P4–P31
NAME
DOUT
SCLK
GND
ISET
N.C.
DIN
CS
V+
EP
Segment Current Setting. Connect ISET to GND through a resistor (R
the maximum segment current.
Ground
4-Wire Serial Data Output Port
LED Segment Drivers and GPIO. P12 to P31 can be configured as CA LED drivers,
GPIO outputs, CMOS logic inputs, or CMOS logic inputs with weak pullup resistor.
LED Segment Drivers and GPIO. P4 to P31 can be configured as CA LED drivers,
GPIO outputs, CMOS logic inputs, or CMOS logic inputs with weak pullup resistor.
4-Wire Serial Clock Input Port
4-Wire Serial Data Input Port
4-Wire Chip-Select Input, Active Low
Positive Supply Voltage. Bypass V+ to GND with a minimum 0.047µF capacitor.
No Connection. Not internally connected.
Exposed Paddle. Internally connected to GND. Connect to large ground plane for
maximum thermal dissipation. Do not use as sole ground connection.
A detected transition is flagged through an interrupt pin
(port P31).
The Typical Operating Circuit shows two MAX6957s
working together controlling three monocolor 16-seg-
ment-plus-DP displays, with five ports left available for
GPIO (P27–P31 of U2).
The port configuration registers set the 28 ports, P4 to
P31, individually as either LED drivers or GPIO. A pair
of bits in registers 0x09 through 0x0F sets each port’s
configuration
The 36-pin MAX6957AAX has 28 ports, P4 to P31. The
28-pin MAX6957ANI and MAX6957AAI make only 20
ports available. The eight unused ports should be con-
figured as outputs on power-up by writing 0x55 to reg-
isters 0x09 and 0x0A. If this is not done, the eight
unused ports remain as floating inputs and quiescent
supply current rises, although there is no damage to
the part.
FUNCTION
(Tables 1 and 2).
Pin Description
ISET
) to set
5