MAX7314 Datasheet, PDF (1/25 Pages) Maxim Integrated Products – 18-Port GPIO with LED Intensity Control, Interrupt, and Hot-Insertion Protection

19-3170; Rev 4; 4/05
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
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
Pin Configurations continued at end of data sheet.
I²C is a trademark of Philips Corp.
Purchase of I²C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys a
license under the Philips I²C Patent Rights to use these compo-
nents in an I²C system, provided that the system conforms to the
I²C Standard Specification as defined by Philips.
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
♦ 1.2µA (typ), 3.6µA (max) Operating Current
♦ Small 4mm x 4mm, Thin QFN Package
♦ -40°C to +125°C Temperature Range
Ordering Information
PART
MAX7314ATG
MAX7314AEG
TEMP RANGE ^PIN-
PACKAGE
24 Thin QFN
-40°C to +125°C 4mm x 4mm
x 0.8mm
-40°C to +125°C 24 QSOP
PKG
CODE
T2444-4
—
Typical Application Circuit
5V
0.047µF
µC
SDA
SCL
I/O
I/O
INT
3.3V
V+
P0
P1
SDA MAX7314 P2
SCL
P3
BLINK
P4
RST
P5
INT/O16
P6
P7
P8
AD0
P9
P10
P11
P12
P13
P14
GND
P15
3.3V
5V
INPUT 1
INPUT 2
INPUT 3
INPUT 4
INPUT 5
OUTPUT
OUTPUT
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