DESCRIPTION

      This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 1.65-V to 5.5-V VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I²C interface [serial clock (SCL), serial data (SDA)]. Two hardware pins (A0 and A1) are used to program and vary the fixed I²C address and allow up to four devices to share the same I²C bus. The AT1116 consists of two 8-bit Configuration (input  or output selection), Input Port, Output Port, and Polarity Inversion (active-high or active-low operation) registers. At power-on, the I/Os are configured as inputs. The system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding Input or output register. The polarity of the Input Port register can be inverted with the Polarity Inversion register. All registers can be read by the system master.

     The system master can reset the AT1116 in the event of a time-out or other improper operation by asserting a low in the RESET input. The power-on reset puts the registers in their default state and initializes the I²C/SMBus state machine. Asserting RESET causes the same reset/initialization to occur without depowering the part.

    The AT1116 open-drain interrupt (INT) output is activated when any input state differs from its corresponding Input Port register state and is used to indicate to the system master that an input state has changed.

     INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I²C bus. Thus, the AT1116 can remain a simple slave device.

     The device outputs (latched) have high-current drive capability for directly driving LEDs. The device has low current consumption.

FEATURES

•     I²C to Parallel Port Expander

•     Supports partial power down i.e. SDA and SCL are 5V tolerant (<1uA leakage) even when  Vcc=0

•     Supports 1.8V I²C operation

•     Open-Drain Active-Low Interrupt Output

•     Active-Low Reset Input

•     I/O Ports are 5V tolerant

•     Low Standby-Current Consumption of 3 μA Max

•     400-kHz Fast I²C Bus support

•     Polarity Inversion Register

•     Configurable with up to four different I²C addresses using hardware pins

•     Directly drive LEDs using high current push pull outputs

•     Latch-Up Performance Exceeds 100 mA Per JESD 78,Class II
  

•     ESD Protection Exceeds JESD 22 

•     – 2000-V Human-Body Model (A114-A)

•     – 1000-V Charged-Device Model (C101) 

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