7.3.2 Power-On Reset (POR)

The DAC82002 device includes a power-on reset function that controls the output voltage at power up. After the

VDD supply has been established, a POR event is issued. The POR causes all registers to initialize to default

values, and communication with the device is valid only after a 250-µs, power-on-reset delay. The default value

at the power-up voltage until a valid command is written to a channel.

When the device powers up, a POR circuit sets the device to the default mode. Figure 7-2 shows that the POR

circuit requires specific VDD levels to make sure that the internal capacitors discharge and reset the device on

power up. To make sure that a POR occurs, VDD must be less than 0.7 V for at least 1 ms. When VDD drops

to less than 2.2 V but remains greater than 0.7 V (shown as the undefined region in the image), the device may

or may not reset under all specified temperature and power-supply conditions; in this case, initiate a POR. When

VDD remains greater than 2.2 V, a POR does not occur.

No power-on reset

Power-on reset

0.70

Undefined

0.00

2.20

2.70

5.50

VDD (V)

Spe cified supply

voltage range

Figure 7-2. Threshold Levels for the VDD POR Circuit

7.3.3 Hardware Reset

immediately after the RESET pin is brought low. The RESET signal resets all internal registers, meaning all

registers initialize to default values. Bring the RESET pin back to high before a write sequence starts. Similar

to the POR delay, communication with the device is valid only after a 250

‑µs delay. The default value for each

DAC channel remains at the reset voltage until a valid command is written to a channel. The RSTSEL pin can

be reconfigured without a power cycle. The DAC output always reflects the current RSTSEL status when the

RESET pin is pulled low.

7.3.4 Software Reset

A device software reset event is initiated by writing the reserved code 0x1010 to the SOFT-RESET bit in the

TRIGGER register (address 5h). A software reset initiates a POR event.

7.4 Device Functional Modes

The DAC82002 has one mode of operation: normal.

In normal mode, the DAC82002 is fully operational. The device translates digital input or reset input to

corresponding analog output.

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DAC82002

SBASAK1 – AUGUST 2022

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