LTC2400 UUWFU CTIO AL BLOCK DIAGRA INTERNAL VCC OSCILLATOR GND AUTOCALIBRATION F AND CONTROL O (INT/EXT) VIN ∫ ∫ ∫ SDO SERIAL ∑ ADC SCK INTERFACE CS VREF DECIMATING FIR DAC 2400 FD TEST CIRCUITS VCC SDO 3.4k 3.4k C SDO LOAD = 20pF CLOAD = 20pF HI-Z TO VOH VOL TO VOH V HI-Z TO V 2400 TA03 OH TO HI-Z OL VOH TO VOL V 2400 TA04 OL TO HI-Z UUWUAPPLICATIONS INFORMATIONConverter Operation Cycle CONVERT The LTC2400 is a low power, delta-sigma analog-to- digital converter with an easy to use 3-wire serial interface. SLEEP Its operation is simple and made up of three states. The converter operating cycle begins with the conversion, followed by a low power sleep state and concluded with 1 CS AND the data output (see Figure 1). The 3-wire interface con- SCK sists of serial data output (SDO), a serial clock (SCK) and 0 a chip select (CS). DATA OUTPUT Initially, the LTC2400 performs a conversion. Once the conversion is complete, the device enters the sleep state. 2400 F01 While in this sleep state, power consumption is reduced by Figure 1. LTC2400 State Transition Diagram 9