SBAS745B December 2015 – January 2023 ADS54J66
PRODUCTION DATA
The ADC test pattern replaces the actual output data of the ADC. The following test patterns are available in register 74h. In order to properly obtain the test pattern output, the interleaving correction must be disabled (6100h, address 18h) and DDC mode-8 must be selected (un-decimated output).
In un-decimated output (DDC mode-8), the device supports LMFS = 4421 only. Available ADC test patterns are summarized in Table 8-4.
BIT | NAME | DEFAULT | DESCRIPTION |
---|---|---|---|
7-4 | TEST PATTERN | 0000 | These bits provide the test pattern output on channels A and B. 0000 = Normal operation using ADC output data 0001 = Outputs all 0s 0010 = Outputs all 1s 0011 = Outputs toggle pattern: output data are an alternating sequence of 101010101010 and 010101010101 0100 = Output digital ramp: output data increment by one LSB every clock cycle from code 0 to 16384 0110 = Single pattern: output data are custom pattern 1 (75h and 76h) 0111 = Double pattern: output data alternate between custom pattern 1 and custom pattern 2 1000 = Deskew pattern: output data are 2AAAh 1001 = SYNC pattern: output data are 3FFFh |