Datasheet

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  
SLIS110A − APRIL 2003 − REVISED MAY 2005
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
programming examples
prescaler/SDO status
D 01000101 programs an input frequency of 6 MHz with SDO terminal in high impedance.
channel selection
D 1110001 selects channel 2.
band-pass frequency
D 00100111 programs a band-pass filter with center frequency of 6.37 kHz.
gain control
D 10010100 programs the gain with attenuation of 0.739.
integrator time constant
D 11000011 programs integrator time constant of 55 µs. The binary values are in Table 1 through Table 3.
programming in TEST mode (TEST = 0)
To enter test mode, the TEST terminal must be low. See Table 4 for the signal that may be accessed in this mode.
Table 4. Programming in TEST Mode
NO. TEST DESCRIPTION
SDI COMMAND
MSB…….LSB
RESPONSE NOTE
T1 AAF individual test 1111 0000 ADC clock Deactivates the input and output op amps
AAF input connected to CH1FB terminal
AAF output connected to OUT terminal
T2 In-line test to AAF output 1111 0000 None Deactivates the output op amp
AAF output connected to OUT terminal
T3 Output buffer individual test 1111 0010 None Opens the feedback loop of the output buffer and
deactivates the input op amp and AAF
CH1FB connected to positive input terminal of op amp
CH2FB connected to negative input terminal of op amp
T4 ADC/DAC individual test
(with the output buffer)
1111 0011 ADC data Deactivates the input op amps and AAF
INT/HOLD = ADC_Sync
OSC
IN
= ADC_SCLK
DAC shifted in from SDI terminal
T5 ADC/DAC individual test
(without the output buffer)
1111 0100 ADC data Deactivates the input op amps, AAF, and output buffer
INT/HOLD = ADC_Sync
OSC
IN
= ADC_SCLK
DAC is shifted in from SDI terminal
T6 In-line test to ADC output 1111 0011 ADC data INT/HOLD = ADC_Sync
OSC
IN
= ADC_SCLK
DAC shifted in from SDI terminal
T7 Reading of digital clamp flag 1111 1000 Clamp flag D[2:0] Implies command 6 (advanced SPI mode)
D[0]: Gain stage clamp status
D[1]: BPF stage clamp status
D[2]: INT stage clamp status
D=0 => No clamp activated
D=1 => Clamp activated