AD780 Analog Devices, AD780 Datasheet
AD780
Available stocks
Related parts for AD780
AD780 Summary of contents
Page 1
... V output from a 5.0 V 10% input, providing a 20% boost to the dynamic range of an ADC over performance with existing 2.5 V references. The AD780 can be used to source or sink mA, and can be used in series or shunt mode, thus allowing positive or negative output voltages without external components. This makes it suitable for virtually any high performance reference application ...
Page 2
... AD780 T ABLE OF CONTENTS Specifications................................. .................................................... 3 Absolute Maximum Ratings............................................................ 4 Notes............................................................................................... 4 ESD Caution.................................................................................. 4 Th eory of Operation ........................................................................ 5 Applying the AD780......................................................................... 6 Noise Performance ....................................................................... 6 Noise Comparison........................................................................ 7 Temperature Performance........................................................... 7 Temperature Output Pin ............................................................. 7 Temperature Transducer Circuit ................................................ 8 R EVISION HISTORY 5/04—Data Sheet Chang ed from Rev Rev. E Updated Format.............................................................. Changes to Temperature Transducer Circuit section ...................8 Changes to Ordering Guide ...........................................................12 1/04— ...
Page 3
... AD780 Unit V V ppm/°C ppm/°C µV/V µV/V µV/mA µV/mA µV/mA µV/mA µV/mA µV/ µV p-p nV/√Hz ± ppm/1000 Hr ± mV/°C kΩ mA °C °C ...
Page 4
... Exposure to absolute maximum specifications for extended periods may affect device reliability. 2.5V/3.0V O/PSELECT (NC OR GND AD780 IN TEMP TOP VIEW OUT (Not to Scale) GND TRIM CONNECT Figure 2 ...
Page 5
... The PTAT voltage is also used to provide the user with a thermometer output voltage (at Pin 3) that increases at a rate of approximately 2 mV/°C. The AD780’s NC (Pin kΩ resistor to +V solely for production test purposes. Users who are currently V 6 OUT ...
Page 6
... Pin 8 is left unconnected or grounded. A bypass capacitor of 1 µF (+V to GND) should be used if the IN load capacitance in the application is expected to be greater than 1 nF. The AD780 in 2.5 V mode typically draws 700 µ This increases by ~2 µA ...
Page 7
... C1 TEMPERATURE OUTPUT PIN The AD780 provides a TEMP output (Pin 3) that varies linearly with temperature. This output can be used to monitor changes in system ambient temperature, and to initiate calibration of the system, if desired. The voltage V temperature coefficient is approximately 2 mV/°C. ...
Page 8
... The two major factors that affect this are the active circuit settling time and the time for the thermal gradients on the chip to stabilize. Typical settling performance is shown in Figure 15. The AD780 settles to within 0.1% of its final value within 10 µs. 10mV/°C AD820 2 ...
Page 9
... One of the many ADCs that the AD780 is suited for is the AD7884, a 16-bit, high speed sampling ADC (see Figure 21). This part previously needed a precision 5 V reference, resistor divider, and buffer amplifier to do this function ...
Page 10
... The AD780 is also ideal for use with higher resolution converters, such as the AD7710/AD7711/AD7712 (see Figure 22. While these parts are specified with a 2.5 V internal reference, the AD780 mode can be used to improve the absolute accuracy, temperature stability, and dynamic range shown in Figure 22 with the two optional noise reduction capacitors ...
Page 11
... PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN Figure 27. 8-Lead Plastic Dual-In-Line Package [PDIP] (N-8) Dimensions shown in inches and (millimeters) Rev Page 0.50 (0.0196) × 45° 0.25 (0.0099) 8° 0° 1.27 (0.0500) 0.40 (0.0157) 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) AD780 ...
Page 12
... AD780BRZ ±1.0 mV −40°C to +85°C AD780BR-REEL ±1.0 mV −40°C to +85°C AD780BR-REEL7 ±1.0 mV −40°C to +85°C 1 AD780BRZ ±1.0 mV −40°C to +85°C 1 AD780BRZ-REEL7 ±1.0 mV −40°C to +85°C AD780CR ±1.5 mV −40°C to +85°C AD780CR-REEL7 ±1.5 mV − ...