MAX7326ATG+T Maxim Integrated Products, MAX7326ATG+T Datasheet - Page 16

• Manufacturer Part Number: MAX7326ATG+T
• Description: IC I/O EXPANDER I2C 16B 24TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX7326ATG+T

• Interface: I²C
• Number Of I /o: 16
• Interrupt Output: Yes
• Frequency - Clock: 400kHz
• Voltage - Supply: 1.71 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-TQFN Exposed Pad
• Includes: POR
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

I
and 4 Inputs
Choose the resistor value according to the following
formula:
where:
R
LED (Ω).
V
V
V
sinking I
I
For example, to operate a 2.2V red LED at 10mA from a
+5V supply:
16
LED
SUPPLY
LED
LED
OL
2
C Port Expander with 12 Push-Pull Outputs
______________________________________________________________________________________
is the output low voltage of the MAX7326 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
is the supply voltage used to drive the LED (V).
R
R
LED
LED
(V).
= (V
= (5 - 2.2 - 0.1) / 0.01 = 270Ω
SUPPLY
- V
LED
- V
OL
) / I
LED
The MAX7326 can be used to drive loads such as
relays that draw more than 20mA by paralleling out-
puts. Use at least one output per 20mA of load current;
for example, a 5V, 330mW relay draws 66mA and
therefore requires four paralleled outputs. Any combi-
nation of outputs can be used as part of a load-sharing
design, because any combination of ports can be set or
cleared at the same time by writing to the MAX7326. Do
not exceed a total sink current of 100mA for the device.
The MAX7326 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.
Choose the peak current for the diode to be greater
than the inductive load’s operating current.
The MAX7326 operates with a supply voltage of
+1.71V to +5.5V over the -40°C to +125°C tempera-
ture range. Bypass the supply to GND with a ceramic
capacitor of at least 0.047µF as close as possible to
the device. For the TQFN version, additionally connect
the exposed paddle to GND.
Driving Load Currents Higher than 20mA
Power-Supply Considerations