Download SERVICE MANUAL
Transcript
ABSOLUTE MAXIMUM RATINGS* PIN FUNCTION DESCRIPTION VDD to DGND ..............................................................................................................................-0.3V to + 7V Pin No. 1 2 3 4 Digital Input Voltage to DGND (CONVST, RD, CS) ...............................................................................................................-0.3V, VDD + 0.3V Digital Output Voltage to DGND (BUSY, DB0-DB7) .................................................................................................................-0.3V, VDD + 0.3V Mnemonic VREF VIN GND CONVST REFIN to AGND ......................................................................................................................-0.3V, VDD + 0.3V Analog Input ..........................................................................................................................-0.3V, VDD + 0.3V Storage Temperature Range.................................................................................................-65 to + 150°C Junction Temperature ........................................................................................................................... 150°C Plastic DIP Package, Power Dissipation .............................................................................................450mW JA Thermal Impedance...................................................................................................................105°C/W Lead Temperature, (Soldering 10 sec)................................................................................................260°C SOIC Package, Power Dissipation ......................................................................................................450mW JA Thermal Impedance .....................................................................................................................75°C/W Lead Temperature, Soldering Vapor Phase (60 sec) ....................................................................................................................215°C Infrared (15 sec)............................................................................................................................220°C SSOP Package, Power Dissipation.....................................................................................................450mW JA Thermal Impedance ...................................................................................................................115°C/W Lead Temperature, Soldering Vapor Phase (60 sec) ....................................................................................................................215°C Infrared (15 sec).............................................................................................................................220°C 5 6 CS RD 7 BUSY 8-15 16 DB0-DB7 VDD Description Reference Input, 1.2V to VDD. Analog Input, 0V to VREF. Analog and Digital Ground. Convert Start. A low-to-high transition on this pin initiates a 1.5 µs pulse on an internally generated CONVST signal. A high-to-low transition on this line initiates the conversion process if the internal CONVST signal is low. Depending on the signal on this pin at the end of a conversion, the AD7819 automatically powers down. Chip Select. This is a logic input. CS is used in conjunction with RD to enable outputs. Read Pin. This is a logic input. When CS is low and RD goes low, the DB7-DB0 leave their high impedance state and data is driven onto the data bus. ADC Busy Signal. This is a logic output. This signal goes logic high during the conversion process. Data Bit 0 to 7. These outputs are three-state TTL-compatible. Positive power supply voltage, 2.7V to 5.5V. PIN CONFIGURATION DIP/SOIC CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charge as high as 4000V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7819 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges, Therefore, proper ESD precaution are recommended to avoid performance degradation or loss of functionality. Figure 1. Load Circuit for Digital Output Timing Specifications ORDERING GUIDE Model AD7819YN AD7819YR AD7819YRU Linearity Error(LSB) ± 1 LSB ± 1 LSB ± 1 LSB Package Description Plastic DIP Small Outline IC Thin Shark Small Outline (TSSOP) Package Option N-16 R-16A RU-16 *Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 8 9