19-3170; Rev 4; 4/05
KIT
ATION
EVALU
E
BL
AVAILA
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
General Description
The MAX7314 I
2
C-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 I
2
C
addresses from only one select pin.
♦
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
Features
♦
400kbps, 2-Wire Serial Interface, 5.5V Tolerant
MAX7314
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
T2444-4
—
MAX7314ATG
MAX7314AEG
24 Thin QFN
-40°C to +125°C 4mm x 4mm
x 0.8mm
-40°C to +125°C 24 QSOP
Typical Application Circuit
5V
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.
0.047μF
μC
SDA
SCL
I/O
I/O
INT
3.3V
V+
SDA
MAX7314
SCL
BLINK
RST
INT/O16
P0
P1
P2
P3
P4
P5
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
________________________________________________________________
Maxim Integrated Products
1
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.
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
MAX7314
ABSOLUTE MAXIMUM RATINGS
Voltage (with respect to GND)
V+ .............................................................................-0.3V to +4V
SCL, SDA, AD0, BLINK,
RST,
P0–P15 .....................-0.3V to +6V
INT/O16
...................................................................-0.3V to +8V
DC Current on P0–P15,
INT/O16
........................................55mA
DC Current on SDA.............................................................10mA
Maximum GND Current ....................................................350mA
Continuous Power Dissipation (T
A
= +70°C)
24-Pin QSOP (derate 9.5mW/°C over +70°C)..............761mW
24-Pin QFN (derate 20.8mW/°C over +70°C) ............1666mW
Operating Temperature Range
(TMIN to TMAX) .............................................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, V+ = 2V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.)
(Note 1)
PARAMETER
Operating Supply Voltage
Output Load External Supply
Voltage
Standby Current
(Interface Idle, PWM Disabled)
SYMBOL
V+
V
EXT
SCL and SDA at V+; other
digital inputs at V+ or GND;
PWM intensity control disabled
SCL and SDA at V+; other
digital inputs at V+ or GND;
PWM intensity control disabled
f
SCL
= 400kHz; other digital
inputs at V+ or GND; PWM
intensity control enabled
f
SCL
= 400kHz; other digital
inputs at V+ or GND; PWM
intensity control enabled
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
0.7
x
V+
0.3
x
V+
0
≤
input voltage
≤
5.5V
-0.2
8
+0.2
57
50
8.5
CONDITIONS
MIN
2
0
1.2
TYP
MAX
3.6
5.5
2.3
2.8
3.6
15.1
16.5
17.2
95.3
99.2
102.4
110.2
117.4
122.1
V
V
µA
pF
µA
µA
µA
µA
UNITS
V
V
I
+
Supply Current
(Interface Idle, PWM Enabled)
Supply Current
(Interface Running, PWM
Disabled)
Supply Current
(Interface Running, PWM
Enabled)
Input High Voltage
SDA, SCL, AD0, BLINK, P0–P15
Input Low Voltage
SDA, SCL, AD0, BLINK, P0–P15
Input Leakage Current
SDA, SCL, AD0, BLINK, P0–P15
Input Capacitance
SDA, SCL, AD0, BLINK, P0–P15
I
+
I
+
I
+
V
IH
V
IL
I
IH
, I
IL
2
_______________________________________________________________________________________
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
ELECTRICAL CHARACTERISTICS (continued)
(Typical Operating Circuit, V+ = 2V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= + 25°C.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
T
A
= +25°C
V+ = 2V, I
SINK
= 20mA
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
Output Low Voltage
P0–P15,
INT/O16
T
A
= +25°C
V
OL
V+ = 2.5V, I
SINK
= 20mA
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
V+ = 3.3V, I
SINK
= 20mA
Output Low-Voltage SDA
PWM Clock Frequency
V
OLSDA
f
PWM
I
SINK
= 6mA
32
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
0.12
0.13
MIN
TYP
0.15
MAX
0.26
0.3
0.32
0.23
0.26
0.28
0.23
0.24
0.26
0.4
V
kHz
V
V
V
UNITS
MAX7314
TIMING CHARACTERISTICS
(Typical Operating Circuit, V+ = 2V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.)
(Note 1)
PARAMETER
Serial Clock Frequency
Bus Free Time Between a STOP and a START
Condition
Hold Time, Repeated START Condition
Repeated START Condition Setup Time
STOP Condition Setup Time
Data Hold Time
Data Setup Time
SCL Clock Low Period
SCL Clock High Period
Rise Time of Both SDA and SCL Signals, Receiving
Fall Time of Both SDA and SCL Signals, Receiving
Fall Time of SDA Transmitting
Pulse Width of Spike Suppressed
Capacitive Load for Each Bus Line
RST
Pulse Width
SYMBOL
f
SCL
t
BUF
t
HD, STA
t
SU, STA
t
SU, STO
t
HD, DAT
t
SU, DAT
t
LOW
t
HIGH
t
R
t
F
t
F.TX
t
SP
C
b
t
W
(Notes 3, 4)
(Notes 3, 4)
(Notes 3, 5)
(Note 6)
(Note 3)
1
(Note 2)
180
1.3
0.7
20 +
0.1C
b
20 +
0.1C
b
20 +
0.1C
b
50
400
300
300
250
1.3
0.6
0.6
0.6
0.9
CONDITIONS
MIN
TYP
MAX
400
UNITS
kHz
µs
µs
µs
µs
µs
ns
µs
µs
ns
ns
ns
ns
pF
µs
_______________________________________________________________________________________
3
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
MAX7314
TIMING CHARACTERISTICS (continued)
(Typical Operating Circuit, V+ = 2V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.)
(Note 1)
PARAMETER
Interrupt Valid
Interrupt Reset
Output Data Valid
Input Data Set-Up Time
Input Data Hold Time
SYMBOL
t
IV
t
IR
t
DV
t
DS
t
DH
CONDITIONS
Figure 10
Figure 10
Figure 10
Figure 10
Figure 10
100
1
MIN
TYP
MAX
6.5
1
5
UNITS
µs
µs
µs
ns
µs
Note 1:
All parameters tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2:
A master device must provide a hold time of at least 300ns for the SDA signal (referred to V
IL
of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 3:
Guaranteed by design.
Note 4:
C
b
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.3 x V
DD
and 0.7 x V
DD
.
Note 5:
I
SINK
≤
6mA. C
b
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.3 x V
DD
and 0.7 x V
DD
.
Note 6:
Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
(PWM DISABLED; f
SCL
= 400kHz)
MAX7314 toc02
MAX7314 toc01
STANDBY CURRENT vs. TEMPERATURE
10
9
STANDBY CURRENT (μA)
8
7
6
5
4
3
2
1
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
V+ = 2V
PWM ENABLED
V+ = 2.7V
V+ = 3.6V
PWM ENABLED
PWM
V+ = 2V
V+ = 2.7V
PWM DISABLED PWM DISABLED DISABLED
V+ = 3.6V
PWM ENABLED
70
60
SUPPLY CURRENT (μA)
50
40
SUPPLY CURRENT vs. TEMPERATURE
(PWM ENABLED; f
SCL
= 400kHz)
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
MAX7314 toc03
V+ = 3.6V
SUPPLY CURRENT (μA)
V+ = 3.6V
V+ = 2.7V
V+ = 2V
V+ = 2.7V
30
20
10
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
V+ = 2V
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
4
_______________________________________________________________________________________
18-Port GPIO with LED Intensity Control,
Interrupt, and Hot-Insertion Protection
MAX7314
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
PORT OUTPUT LOW VOLTAGE WITH 50mA
LOAD CURRENT vs. TEMPERATURE
MAX7314 toc04
PORT OUTPUT LOW VOLTAGE WITH 20mA
LOAD CURRENT vs. TEMPERATURE
MAX7314 toc05
PWM CLOCK FREQUENCY
vs. TEMPERATURE
MAX7314 toc06
0.6
PORT OUTPUT LOW VOLTAGE V
OL
(V)
0.5
V+ = 2.7V
0.4
0.3
0.2
0.1
0
V+ = 3.6V
V+ = 2V
0.6
PORT OUTPUT LOW VOLTAGE V
OL
(V)
0.5
0.4
0.3
0.2
0.1
0
ALL OUTPUTS LOADED
1.050
PWM CLOCK FREQUENCY (kHz)
1.025
1.000
0.975
V+ = 2.7V
0.950
0.925
0.900
NORMALIZED TO V+ = 3.3V, T
A
= +25°C
V+ = 2V
V+ = 3.6V
V+ = 2V
V+ = 2.7V
V+ = 3.6V
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
SCOPE SHOT OF 2 OUTPUT PORTS
MAX7314 toc07
SCOPE SHOT OF 2 OUTPUT PORTS
MAX7314 toc08
SINK CURRENT vs. V
OL
OUTPUT 1 0.30
2V/div
0.25
V
OL
(V)
0.20
V+ = 3.3V
0.15
V+ = 3.6V
MAX7314 toc09
0.35
V+ = 2V
V+ = 2.7V
MASTER INTENSITY SET TO 1/15
OUTPUT 1,
2V/div
OUTPUT 1 INDIVIDUAL INTENSITY
SET TO 1/16
MASTER INTENSITY SET TO 14/15
OUTPUT 1 INDIVIDUAL INTENSITY
SET TO 1/16
OUTPUT 2,
2V/div
OUTPUT 2 INDIVIDUAL INTENSITY
SET TO 15/16
2ms/div
OUTPUT 2 INDIVIDUAL INTENSITY
SET TO 14/15
2ms/div
OUTPUT 2
0.10
2V/div
0.05
0
0
5
ONLY ONE OUTPUT LOADED
10 15 20 25 30 35 40 45 50
SINK CURRENT (mA)
_______________________________________________________________________________________
5
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