16-channel I2C GPIO expanders have configurable pull up resistor
I2C general purpose I/O (GPIO) expanders by Nexperia provide additional I/O while keeping the interconnections to a minimum. Using them, said the company, design engineers can add new features without increasing PCB design complexity and the bill of materials.
The GPIO expanders include the NCA9595, claimed to be the industry’s first to feature a register configurable internal pull-up resistor. This removes the requirement for external pull-up resistors (saving board space and cost) and allows power consumption to be optimised based on customer requirements.
The number of sensor signals which require monitoring by a microcontroller continues to increase in line with the growth of the servers, automotive, industrial, medical and the IoT, as does the number of LEDs used as system status indicators. Microcontrollers are designed with limited numbers of GPIO ports, many are used internally within a system, leaving only a small number of I/Os available to connect to sensors or LEDs. With this limitation, I2C GPIO provides an additional 128 I/O channels.
The company has also released the NCA9535, NCA9539, NCA9555 and NCA9595 12C GPIOs. These have been designed in pin-to-pin compatible packages with industry standard footprints (TSSOP24 and HWQFN24) and are a cost-effective way to expand the number of parallel IOs in an electronic system, said Nexperia.
All parts have standby current of 2.5 microA, which is 28 per cent lower than competing devices, claimed Nexperia. They also have output capacitance of 4.5pF, which is 45 per cent lower and propagation delay of 280ns which is claimed to be six per cent faster than competing devices. All of these characteristics enable lower power and faster GPIO to I2C (and reverse) response, respectively. All devices operate over a 1.65 to 5.5V range and from -40 to +85 degrees C and -40 to +125 degrees C temperature ranges.
Nexperia has a portfolio of semiconductors, including diodes, bipolar transistors, ESD protection devices, MOSFETs, GaN FETs and analogue and logic ICs. The company is headquartered in Nijmegen, the Netherlands and has employees across Asia, Europe and the USA. Nexperia, a subsidiary of Wingtech Technology also has an extensive IP portfolio and is certified to IATF 16949, ISO 9001, ISO 14001 and ISO 45001.
