DAC3482_15 Datasheet, PDF (51/106 Pages) Texas Instruments – DAC3482, Dual-Channel, 16-Bit, 1.25 GSPS Digital-to-Analog Converter (DAC)

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DAC3482
SLAS748F – MARCH 2011 – REVISED AUGUST 2015
Parity alarms
• alarm_rparity. Occurs when there is a parity error in the data captured by the rising edge of DATACLKP/N.
The PARITYP/N input is the parity bit (word-by-word parity test).
• alarm_fparity. Occurs when there is a parity error in the data captured by the falling edge of DATACLKP/N.
The PARITYP/N input is the parity bit (word-by-word parity test).
• alarm_frame_parity_err. Occurs when there is a frame parity error when using the FRAME as the parity bit
(block parity test).
To prevent unexpected DAC outputs from propagating into the transmit channel chain, the clock and alarm_
fifo_collision alarms can be set in config2 to shut-off the DAC output automatically regardless of the state of
TXENABLE or sif_txenable.
Alarm monitoring is implemented as follows:
• Power up the device using the recommended power-up sequence.
• Clear all the alarms in config5 by setting them to 0b.
• Unmask those alarms that will generate a hardware interrupt through the ALARM pin in config7.
• Enable automatic DAC shut-off in register config2 if required.
• In the case of an alarm event, the ALARM pin will trigger. If automatic DAC shut-off has been enabled the
DAC outputs will be disabled.
• Read registers config5 to determine which alarm triggered the ALARM pin.
• Correct the error condition and re-synchronize the FIFO.
• Clear the alarms in config5.
• Re-read config5 to ensure the alarm event has been corrected.
• Keep clearing and reading config5 until no error is reported.
For details of alarm monitoring function and behavior, refer to application report SLAA585.
7.3.13 LVPECL Inputs
Figure 79 shows an equivalent circuit for the DAC input clock (DACCLKP/N) and the output strobe clock
(OSTRP/N).
CLKVDD
250 Ω
DACCLKP
OSTRP
SLEEP
250 Ω
2 kΩ
2 kΩ
Internal
Digital In
DACCLKN
OSTRN
GND
Figure 79. DACCLKP/N and OSTRP/N Equivalent Input Circuit
S0515-01
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