Datasheet AD7992 (Analog Devices) - 9

link to page 18 link to page 18 link to page 9 link to page 26 link to page 19 link to page 29
AD7992 PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS CONVST 1 10 SCL AGND 2 9 SDA VDD 3 AD7992 8 ALERT V 4 IN2/REFIN TOP VIEW 7 AGND V 5 (Not to Scale) 6 AS IN1
03263-0-002 Figure 3. AD7992 Pin Configuration
Table 5. Pin Function Descriptions Pin No. Mnemonic Function
2, 7 AGND Analog Ground. Ground reference point for all circuitry on the AD7992. All analog input signals should be referred to this GND voltage. 3 VDD Power Supply Input. The VDD range for the AD7992 is from 2.7 V to 5.5 V. 4 VIN2/REFIN Analog Input 2/Voltage Reference Input. In single-channel mode, this pin becomes the reference voltage input; an external reference should be applied at this pin. The external reference input range is 1.2 V to VDD. A 0.1 µF and 1µF capacitor should be tied between this pin and AGND. If Bit D6 is set to 1 in the configuration register, the AD7992 operates in single-channel mode. In dual-channel mode, D6 in the configuration register is 0; in this case, this pin provides the second analog input channel. The reference voltage for the AD7992 is taken from the power supply voltage in dual-channel mode. See the Configuration Register section and Table 10. 5 VIN1 Analog Input 1. Single-ended analog input channel. The input range is 0 V to REFIN. 6 AS Logic Input. Address select input that selects one of three I2C addresses for the AD7992, as shown in Table 6. 1 CONVST Logic Input Signal. Convert start signal. This is an edge-triggered logic input. The rising edge of this signal powers up the part. The power up time for the part is 1 µs. The falling edge of CONVST places the track-and- hold into hold mode and initiates a conversion. A power-up time of at least 1 µs must be allowed for the CONVST high pulse; otherwise, the conversion result is invalid (see the Modes of Operation section). 8 ALERT/BUSY Digital Output. Selectable as an ALERT or BUSY output function. When configured as an ALERT, this pin acts as an out-of-range indicator and, if enabled, becomes active when the conversion result violates the DATAHIGH or DATALOW register values. See the Limit Registers section. When configured as a BUSY output, this pin becomes active when a conversion is in progress. Open-drain output. An external pull-up resistor is required. 9 SDA Digital I/O. Serial bus bidirectional data. Open-drain output. An external pull-up resistor is required. 10 SCL Digital Input. Serial bus clock. Open-drain output. An external pull-up resistor is required.
Table 6. I2C Address Selection Part Number AS Pin I2C Address
AD7992-0 GND 010 0001 AD7992-0 VDD 010 0010 AD7992-1 GND 010 0011 AD7992-1 VDD 010 0100 AD7992-x1 Float 010 0000 1 If the AS pin is left floating on any of the AD7992 parts, the device address is 010 0000. This gives each AD7992 device three different address options. Rev. 0 | Page 8 of 28 Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS I2C TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS CIRCUIT INFORMATION CONVERTER OPERATION TYPICAL CONNECTION DIAGRAM ANALOG INPUT INTERNAL REGISTER STRUCTURE ADDRESS POINTER REGISTER CONFIGURATION REGISTER CONVERSION RESULT REGISTER LIMIT REGISTERS ALERT STATUS REGISTER CYCLE TIMER REGISTER SAMPLE DELAY AND BIT TRIAL DELAY SERIAL INTERFACE SERIAL BUS ADDRESS WRITING TO THE AD7992 WRITING TO THE ADDRESS POINTER REGISTER FOR A SUBSEQUENT REA WRITING A SINGLE BYTE OF DATA TO THE ALERT STATUS REGISTER, WRITING TWO BYTES OF DATA TO A LIMITREGISTER OR HYSTERESIS READING DATA FROM THE AD7992 ALERT/BUSY PIN SMBus ALERT PLACING THE AD7992-1 INTO HIGH SPEED MODE THE ADDRESS SELECT (AS) PIN MODES OF OPERATION MODE 1—USING THE /CONVST PIN MODE 2 – COMMAND MODE MODE 3—AUTOMATIC CYCLE MODE OUTLINE DIMENSIONS ORDERING GUIDE