General Description
The MAX7314 I2C-compatible serial interfaced periph-
eral provides microprocessors with 16 I/O ports plus one
output-only port and one input-only port. Each I/O port
can be individually configured as either an open-drain
current-sinking output rated at 50mA and 5.5V, or a logic
input with transition detection. The output-only port can
be assigned as an interrupt output for transition detec-
tion. The outputs are capable of driving LEDs, or provid-
ing logic outputs with external resistive pullup up to 5.5V.
Eight-bit PWM current control is built in for all 17 output
ports. A 4-bit global control applies to all LED outputs
and provides coarse adjustment of current from fully off
to fully on with 14 intensity steps in between. Each out-
put has an individual 4-bit control, which further divides
the globally set current into 16 more steps.
Alternatively, the current control can be configured as a
single 8-bit control that sets all outputs at once.
Each output has independent blink timing with two blink
phases. All LEDs can be individually set to be on or off
during either blink phase, or to ignore the blink control.
The blink period is controlled by a clock input (up to 1kHz)
on BLINK or by a register. The BLINK input can also be
used as a logic control to turn the LEDs on and off, or as a
general-purpose input.
The MAX7314 supports hot insertion. All port pins, the
INT output, SDA, SCL, RST, BLINK, and the slave
address input ADO remain high impedance in power-
down (V+ = 0V) with up to 6V asserted upon them.
The MAX7314 is controlled through a 2-wire serial inter-
face, and uses four-level logic to allow four I2C
addresses from only one select pin.
Applications
LCD Backlights
LED Status Indication
Relay Drivers
Keypad Backlights
RGB LED Drivers
System I/O Ports
Features
400kbps, 2-Wire Serial Interface, 5.5V Tolerant
2V to 3.6V Operation
Overall 8-Bit PWM LED Intensity Control
Global 16-Step Intensity Control
Individual 16-Step Intensity Controls
2-Phase LED Blinking
50mA Maximum Port Output Current
Supports Hot Insertion
Outputs are 5.5V-Rated Open Drain
Inputs are Overvoltage Protected to 5.5V
Transition Detection with Interrupt Output
1.2A (typ), 3.6A (max) Operating Current
Small 4mm x 4mm, Thin QFN Package
-40°C to +125°C Temperature Range
MAX7314
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
________________________________________________________________ Maxim Integrated Products
1
MAX7314
P8
P10
P0
P1
P2
P3
P4
P5
P6
P7
V+
3.3V
μC
SDA
AD0
3.3V
5V
P11
P12
P13
P14
P15
SCL
BLINK
I/O
RST
I/O
P9
OUTPUT
GND
5V
INPUT 1
INPUT 2
INPUT 3
INPUT 4
INPUT 5
0.047
μF
INT
INT/O16
Typical Application Circuit
19-3170; Rev 4; 4/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
EVALUATION
KIT
AVAILABLE
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
MAX7314ATG
-40
°C to +125°C
24 Thin QFN
4mm x 4mm
x 0.8mm
T2444-4
MAX7314AEG
-40
°C to +125°C 24 QSOP
—
Pin Configurations continued at end of data sheet.