ADT7518

The ADT75181 combines a 10-bit temperature-to-digital converter, a 10-bit 4-channel ADC, and a quad 8-bit DAC, in a 16-lead QSOP package. The part also includes a band gap temperature sensor and a 10-bit ADC to monitor and digitize the temperature reading to a resolution of 0.25°C.

The ADT7518 operates from a single 2.7 V to 5.5 V supply. The input voltage range on the ADC channels is 0 V to 2.25 V, and the input bandwidth is dc. The reference for the ADC channels is derived internally. The output voltage of the DAC ranges from 0 V to VDD, with an output voltage settling time of 7 ms typical.

The ADT7518 provides two serial interface options: a 4-wire serial interface that is compatible with SPI, QSPI, MICROWIRE, and DSP interface standards, and a 2-wire SMBus/I2C interface. It features a standby mode that is controlled through the serial interface. The reference for the four DACs is derived either internally or from a reference pin. The outputs of all DACs may be updated simultaneously using the software LDAC function or the exter-nal LDAC pin. The ADT7518 incorporates a power-on reset circuit, which ensures that the DAC output powers up to 0 V and remains there until a valid write takes place.

The ADT7518's wide supply voltage range, low supply current, and SPI-/I2C-compatible interface make it ideal for a variety of applications, including personal computers, office equipment, and domestic appliances.

It is recommended that new designs use the ADT7519 rather than the ADT7518. Its internal and external temp-erature accuracy spec is only valid when not using the internal reference for the on-chip DAC. The ADT7519 does not have this limitation.