JAJSTM8 April 2024 AFE20408
PRODUCTION DATA
The DAC output buffer amplifiers are capable of rail-to-rail operation. The amplifier outputs are available at the DAC output pins. The buffer amplifiers for the two DAC groups are biased from dedicated supply rails: VCC[A,B] and VSS[A,B]. The maximum DAC group output voltage range is limited by these supplies.
The output amplifier is designed to drive capacitive loads without oscillation. The output buffers are able to source and sink up to 120mA. The device implements short-circuit protection for momentary output shorts to ground and either supply. The source and sink short-circuit current can be configured to either 30mA for low-current mode, 90mA for normal-current mode, or 120mA for high-current mode. The desired current mode can be set by writing to the DAC_CURRENT register in the DAC Configuration register page.
The high output current of the device gives good slewing characteristics even with large capacitive loads. To estimate the positive and negative slew rates for large capacitive loads, divide the source and sink short-circuit current value by the capacitor.
After start up, the DAC outputs are set automatically into VSS clamp mode and the range for each group is configured automatically by the voltage present in the VSS[A,B] and VCC[A,B] pins. In VSS clamp mode, the DAC output pins are internally connected to the VSS[A,B] pins through a current limited discharge path. The DAC outputs remain in VSS clamp mode until the DAC output buffers are powered up through the power enable registers.