Monthly Archives: April 2017

Dual supply translating transceiver; open drain; auto direction sensing

Featuring two 4-bit input-output ports, the NTS0104-Q100 is a 4-bit, dual supply translating transceiver with auto direction sensing, that enables bidirectional voltage level translation. This device is fully specified for partial power-down applications using IOFF. The IOFF circuitry disables the output, preventing the damaging backflow current through the device when it is powered down.

This product has been qualified to the Automotive Electronics Council (AEC) standard Q100 (Grade 1) and is suitable for use in automotive applications.

Logic Symbol

Logic Symbol

Why Used

  • IOFF circuitry provides partial Power-down mode operation
  • Inputs accept voltages up to 5.5 V
  • Latch-up performance exceeds 100 mA per JESD 78B Class II
  • Multiple package options

Where Used

  • I²C/SMBus
  • UART
  • GPIO

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Parallel bus to 1 channel Fm+ and 2 channel UFm I2C-bus controller

Designed for data intensive I²C-bus data transfers, the PCU9669 is an advanced single master mode I²C-bus controller. It is a fourth generation bus controller which has three independent I²C-bus channels, one of them with data rates up to 1 Mbits/s using the Fast-mode Plus (Fm+) open-drain topology and two with a much larger transmit only transfer rate of up to 5 Mbits/s using the new Ultra Fast-mode (UFm) bus with push-pull topology.

The PCU9669 is a 8-bit parallel-bus to I²C-bus protocol converter. It can be configured to communicate with up to 64 slaves in one serial sequence with no intervention from the CPU. The controller also has a sequence loop control feature that allows it to automatically retransmit a stored sequence.

Block Diagram

Block Diagram

Why Used

  • Parallel-bus to I²C-bus protocol converter and interface
  • Internal oscillator trimmed to 1 % accuracy reduces external components
  • Communicates with up to 64 slaves in one serial sequence
  • Supports SCL clock stretching (Fm+ only)
  • Fast-mode Plus I²C-bus capable and compatible with SMBus

Where Used

  • Add I²C-bus port to controllers/processors that do not have one
  • Add additional I²C-bus ports to controllers/processors that need multiple I²C-bus ports
  • Entertainment systems
  • LED matrix control
  • Data intensive I²C-bus transfers

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18 V tolerant SPI 8-bit GPI with maskable INT

Generating an interrupt when one or more of the switch inputs change, the PCA9704 is a low power 18 V tolerant SPI General Purpose Input (GPI) shift register designed to monitor the status of switch inputs. The input level is recognized as a HIGH when it is greater than 0.8 x VDD and as a LOW hen it is less than 0.55 xVDD (minimum LOW threshold of 2.5 V at 5 V node).

Multiple PCA9704 devices can be serially connected for monitoring a large number of switches by connecting the SDOUT of one device to the SDIN of the next device. SCLK and CS must be common among all devices and interrupt outputs may be tied together. No external logic is necessary because all the devices’ interrupt outputs are open-drain that function as ‘wired-AND’ and can simply be connected together to a single pull-up resistor.

Block diagram of PCA9704

Block diagram of PCA9704

Why Used

  • 8 general purpose input ports
  • Open-drain interrupt output
  • Interrupt-masking feature allows no interrupt generation from selected inputs
  • SPI supports daisy-chain connection for large switch numbers
  • ESD protection exceeds 5 kV HBM per JESD22-A114 and 1000 V CDM per JESD22-C101

Where Used

  • Body control modules
  • Electronic control units (for example, for body controller)
  • Switch monitoring
  • SBC wake pin extension
  • Industrial equipment
  • Cellular telephones
  • Emergency lighting

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SIM card interface level translator with I2C-bus control and LDO

Available in a 12-pin WLCSP package, the NVT4556 device is built for interfacing a SIM card with a single low-voltage host-side interface. The NVT4556 contains an LDO that can deliver two different voltages, 1.8 V or 3 V, from a typical mobile phone battery voltage, and three level translators to convert the data, RSTn and CLKn signals between a SIM card and a host microcontroller.

The NVT4556 VCC pin provides power to the host side I/Os and doubles as an enable pin, for this reason it can be connected to a GPIO that matches the host side voltage. The total current draw from the VCC pin is only 100 μA maximum. The NVT4556 also uses the I²C-bus interface to enable normal operation and to select either 1.8 V or 3 V for the SIM card power supply. The NVT4556 can also disable the LDO functionality while maintaining the level translator paths so that the user can use a system-controlled regulator to power the SIM card power supply.

Functional diagram

Functional diagram

Why Used

  • Support SIM card supply voltages 1.8 V and 3 V
  • I²C-bus interface for device enable and LDO voltage selection
  • Supports CLK stop mode
  • Supports clock speed beyond 5 MHz clock
  • Integrated EMI filters

Where Used

  • Mobile and personal phones
  • Wireless modems
  • SIM card terminals

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