MAX7313ATG+T Maxim Integrated Products, MAX7313ATG+T Datasheet - Page 24

• Manufacturer Part Number: MAX7313ATG+T
• Description: IC I/O EXPANDER I2C 16B 24TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX7313ATG+T

• Interface: I²C
• Number Of I /o: 16
• 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: 24-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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
The MAX7313 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, or the P8 through P15
range. This way, the paralleled outputs are turned on
and off together. Do not use output O16 as part of a
load-sharing design. O16 cannot be switched at the
same time as any of the other outputs because it is con-
trolled by a different register.
The MAX7313 must be protected from the negative
voltage transient generated when switching off induc-
tive loads, such as relays, by connecting a reverse-
biased diode across the inductive load (Figure 18). The
peak current through the diode is the inductive load’s
operating current.
16-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
24
LED
SUPPLY
LED
OL
LED
Driving Load Currents Higher than 50mA
______________________________________________________________________________________
is the output low voltage of the MAX7313 when
is the desired operating current of the LED (A).
is the forward voltage of the LED (V).
is the resistance of the resistor in series with the
LED
R
is the supply voltage used to drive the LED (V).
LED
(V).
LED
= (V
= (5 - 2.2 - 0.25) / 0.014 = 182Ω.
SUPPLY
- V
LED
Driving LED Loads
- V
OL
) / I
LED
The MAX7313 operates with a power-supply voltage of
2V to 3.6V. Bypass the power supply to GND with at
least 0.047µF as close to the device as possible.
For the QFN version, connect the underside exposed
pad to GND.
Figure 18. Diode-Protected Switching Inductive Load
μC
0.047μF
SDA
SCL
I/O
2V TO 3.6V
SDA
SCL
INT/O16
AD0
AD1
AD2
Power-Supply Considerations
V+
MAX7313
GND
P10
P11
P12
P13
P14
P15
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
BAS16
5V