PCA9557PWR

This 8-bit I/O expander for the two-wire bidirectional bus (I²C) is designed to operate at VCC from 2.3V to 5.5V. The device provides general-purpose remote I/O expansion for most microcontroller families via the I²C interface [serial clock (SCL) and serial data (SDA)]. The PCA9557 contains an 8-bit configuration (selectable as input or output), input port, output port, and polarity inversion (active-HIGH) registers. At power-on, the I/Os are configured as inputs. However, the system controller can enable the I/Os as inputs or outputs by writing to the I/O configuration bits. Data for each input or output is held in the corresponding input or output register. The polarity of the input port register can be inverted using the polarity inversion register. All registers are readable by the system controller. The device outputs (latched) feature high-current drive capability for direct LED driving. The device has low current consumption. When a timeout or other improper operation occurs, the system controller can reset the PCA9557 by asserting the active-LOW reset (RESET) input low. A power-on reset places the registers in their default state and initializes the I²C/SMBus state machine. Asserting RESET also achieves reset and initialization without the need to power down the device.

Applications

• Telecom shelters: filter units
• Servers
• Routers (telecom switching equipment)
• Personal computers
• Consumer electronics
• Industrial automation
• Products with GPIO restrictions

Key features

• Standby current: 1μA maximum
• I²C to parallel port expander
• Operating supply voltage range: 2.3V to 5.5V
• 5V-tolerant I/O ports
• 400kHz fast-mode I²C bus
• Three hardware address pins allow up to eight devices on I²C/SMBus
• Low-voltage, high-performance migration path for PCA9556
• Input and output configuration registers
• Polarity inversion register
• Active-low reset input
• Internal power-on reset
• High-impedance open-drain on P0
• All channels configured as inputs at power-up
• No glitch at power-up
• Noise filter on SCL or SDA inputs
• Latched outputs with maximum high-current drive capability for direct LED driving
• Latch-up performance exceeds 100mA per JESD78 Class II
• ESD protection exceeds JESD22 requirements
• 2000V Human Body Model (A114-A)
• 200V Machine Model (A115-A)
• 1000V Charged Device Model (C101)