Datasheet LTC2421, LTC2422 (Analog Devices) - 9

LTC2421/LTC2422
U U U PIN FUNCTIONS SCK (Pin 9):
Bidirectional Digital Clock Pin. In the Internal
FO (Pin 10):
Frequency Control Pin. Digital input that Serial Clock Operation mode, SCK is used as digital output controls the ADC’s notch frequencies and conversion for the internal serial interface clock during the data output time. When the FO pin is connected to VCC (FO = VCC), the period. In the External Serial Clock Operation mode, SCK converter uses its internal oscillator and the digital filter’s is used as digital input for the external serial interface. An first null is located at 50Hz. When the FO pin is connected internal pull-up current source is automatically activated to GND (FO = 0V), the converter uses its internal oscillator in Internal Serial Clock Operation mode. The Serial Clock and the digital filter’s first null is located at 60Hz. When FO mode is determined by the level applied to SCK at power is driven by an external clock signal with a frequency fEOSC, up and the falling edge of CS. the converter uses this signal as its clock and the digital filter first null is located at a frequency fEOSC/2560.
U U W FUNCTIONAL BLOCK DIAGRA
INTERNAL VCC OSCILLATOR GND AUTOCALIBRATION F AND CONTROL O (INT/EXT) VIN ∫ ∫ ∫ SDO SERIAL ∑ ADC SCK INTERFACE CS VREF DECIMATING FIR DAC 24212 FD
TEST CIRCUITS
VCC 3.4k SDO SDO 3.4k CLOAD = 20pF CLOAD = 20pF Hi-Z TO VOH Hi-Z TO VOL VOL TO VOH VOH TO VOL V V 24212 TC01 OH TO Hi-Z 24212 TC02 OL TO Hi-Z 24212f 9