JAJSLP1 September 2023 DAC43901-Q1 , DAC43902-Q1
PRODUCTION DATA
The DAC4390x-Q1 devices have a 2-wire serial interface (SCL and SDA), and one address pin (A0), as shown in the pin diagram in the Pin Configuration and Functions section. The I2C bus consists of a data line (SDA) and a clock line (SCL) with pullup structures. When the bus is idle, both SDA and SCL lines are pulled high. All the I2C-compatible devices connect to the I2C bus through the open drain I/O pins, SDA and SCL.
The I2C specification states that the device that controls communication is called a controller, and the devices that are controlled by the controller are called targets. The controller generates the SCL signal. The controller also generates special timing conditions (start condition, repeated start condition, and stop condition) on the bus to indicate the start or stop of a data transfer. Device addressing is completed by the controller. The controller on an I2C bus is typically a microcontroller or digital signal processor (DSP). The DAC4390x-Q1 family operates as a target on the I2C bus. A target acknowledges controller commands, and upon controller control, receives or transmits data.
Typically, the DAC4390x-Q1 family operates as a target receiver. A controller writes to the DAC4390x-Q1, a target receiver. However, if a controller requires the DAC4390x-Q1 internal register data, the DAC4390x-Q1 operate as a target transmitter. In this case, the controller reads from the DAC4390x-Q1. According to I2C terminology, read and write refer to the controller.
The DAC4390x-Q1 family supports the following data transfer modes:
The data transfer protocol for standard and fast modes is exactly the same; therefore, both modes are referred to as F/S-mode in this document. The fast mode plus protocol is supported in terms of data transfer speed, but not output current. The low-level output current is 3 mA; similar to the case of standard and fast modes. The DAC4390x-Q1 family supports 7-bit addressing. The 10-bit addressing mode is not supported. The device supports the general call reset function. Sending the following sequence initiates a software reset within the device: start or repeated start, 0x00, 0x06, stop. The reset is asserted within the device on the rising edge of the ACK bit, following the second byte.
Other than specific timing signals, the I2C interface works with serial bytes. At the end of each byte, a ninth clock cycle generates and detects an acknowledge signal. An acknowledge is when the SDA line is pulled low during the high period of the ninth clock cycle. A not-acknowledge is when the SDA line is left high during the high period of the ninth clock cycle, as shown in Figure 7-15.