MAX7316AEE+T Maxim Integrated Products, MAX7316AEE+T Datasheet - Page 19

• Manufacturer Part Number: MAX7316AEE+T
• Description: IC I/O EXPANDER I2C 16B 16QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX7316AEE+T

• Interface: I²C, SMBus
• Number Of I /o: 10
• Interrupt Output: Yes
• Frequency - Clock: 400kHz
• Voltage - Supply: 2 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 12. PWM Intensity Settings (Blink Enabled)
When driving LEDs, a resistor in series with the LED
must be used to limit the LED current to no more than
50mA. Choose the resistor value according to the fol-
lowing formula:
where:
R
LED (Ω).
V
V
V
sinking I
I
For example, to operate a 2.2V red LED at 14mA from a
5V supply, R
LED
INTENSITY
SUPPLY
LED
LED
OL
Control, Interrupt, and Hot-Insertion Protection
GLOBAL)
SETTING
OUTPUT
(OR
0xA
0xB
0xC
0xD
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
0x8
0x9
0xE
0xF
is the desired operating current of the LED (A).
is the output low voltage of the MAX7316 when
is the forward voltage of the LED (V).
is the resistance of the resistor in series with the
LED
is the supply voltage used to drive the LED (V).
R
LED
(V).
LED
Static low
PWM DUTY CYCLE
REGISTER BIT = 0
= (V
10/16
11/16
12/16
13/16
14/16
15/16
LOW
TIME
1/16
2/16
3/16
4/16
5/16
6/16
7/16
8/16
9/16
OUTPUT BLINK
= (5 - 2.2 - 0.25) / 0.014 = 182Ω.
______________________________________________________________________________________
SUPPLY
PHASE X
10-Port I/O Expander with LED Intensity
Static low
HIGH
15/16
14/16
13/16
12/16
11/16
10/16
TIME
- V
9/16
8/16
7/16
6/16
5/16
4/16
3/16
2/16
1/16
LED
Driving LED Loads
- V
impedance
Static high
OL
PWM DUTY CYCLE
REGISTER BIT = 1
15/16
14/16
13/16
12/16
11/16
10/16
LOW
TIME
9/16
8/16
7/16
6/16
5/16
4/16
3/16
2/16
1/16
OUTPUT BLINK
) / I
PHASE X
LED
impedance
Static high
HIGH
10/16
11/16
12/16
13/16
14/16
15/16
TIME
1/16
2/16
3/16
4/16
5/16
6/16
7/16
8/16
9/16
P hase 0: LE D on at hi g h i ntensi ty
P hase 1: LE D on at hi g h i ntensi ty
P hase 1: LE D on at l ow i ntensi ty
Phase 0: LED on continuously
Phase 1: LED off continuously
P hase 0: LE D on at l ow i ntensi ty
The MAX7316 can be used to drive loads drawing more
than 50mA, like relays and high-current white LEDs, by
paralleling outputs. Use at least one output per 50mA of
load current; for example, a 5V 330mW relay draws
66mA and needs two paralleled outputs to drive it.
Ensure that the paralleled outputs chosen are controlled
by the same blink phase register, i.e., select outputs
from the P0 through P7 range. This way, the paralleled
outputs are turned on and off together. Do not use out-
put O8 as part of a load-sharing design. O8 cannot be
switched at the same time as any of the other outputs
because it is controlled by a different register.
REGISTER BIT = 0
REGISTER BIT = 1
Driving Load Currents Higher than 50mA
BLINK PHASE 0
BLINK PHASE 1
Output is half intensity during both blink phases
EXAMPLES OF LED BLINK BEHAVIOR
(LED IS ON WHEN OUTPUT IS LOW)
P hase 0: LE D on at hi g h i ntensi ty
P hase 1: LE D on at l ow i ntensi ty
P hase 1: LE D on at hi g h i ntensi ty
Phase 0: LED off continuously
Phase 1: LED on continuously
P hase 0: LE D on at l ow i ntensi ty
REGISTER BIT = 1
REGISTER BIT = 0
BLINK PHASE 0
BLINK PHASE 1
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