AD790

a FEATURES 45 ns max Propagation Delay Single 5 V or Dual 15 V Supply Operation CMOS or TTL Compatible Output 250 V max Input Offset Voltage 500 V max Input Hysteresis Voltage 15 V max Differential Input Voltage Onboard Latch 60 mW Power Dissipation Available in 8-Pin Plastic and Hermetic Cerdip Packages Available in Tape and Reel in Accordance with EIA-481A Standard APPLICATIONS Zero-Crossing Detectors Overvoltage Detectors Pulse-Width Modulators Precision Rectifiers Discrete A/D Converters Delta-Sigma Modulator A/Ds +VS +IN –IN –VS Fast, Precision Comparator AD790 CONNECTION DIAGRAMS 8-Pin Plastic Mini-DIP (N) and Cerdip (Q) Packages 1 8 AD790 2 3 4 VLOGIC OUTPUT GROUND LATCH + – 7 6 5 8-Pin SOIC (R) Package 1 2 GROUND LATCH –VS –IN OUTPUT VLOGIC +VS +IN AD790 8 7 4 + 3 – 6 5 PRODUCT DESCRIPTION PRODUCT HIGHLIGHTS The AD790 is a fast (45 ns), precise voltage comparator, with a number of features that make it exceptionally versatile and easy to use. The AD790 may operate from either a single 5 V supply or a dual ± 15 V supply. In the single-supply mode, the AD790’s inputs may be referred to ground, a feature not found in other comparators. In the dual-supply mode it has the unique ability of handling a maximum differential voltage of 15 V across its input terminals, easing their interfacing to large amplitude and dynamic signals. This device is fabricated using Analog Devices’ Complementary Bipolar (CB) process—which gives the AD790’s combination of fast response time and outstanding input voltage resolution (1 mV max). To preserve its speed and accuracy, the AD790 incorporates a “low glitch” output stage that does not exhibit the large current spikes normally found in TTL or CMOS output stages. Its controlled switching reduces power supply disturbances that can feed back to the input and cause undesired oscillations. The AD790 also has a latching function which makes it suitable for applications requiring synchronous operation. The AD790 is available in five performance grades. The AD790J and the AD790K are rated over the commercial temperature range of 0°C to 70°C. The AD790A and AD790B are rated over the industrial temperature range of –40°C to +85°C. The AD790S is rated over the military temperature range of –55°C to +125°C. R EV. D Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. 1. The AD790’s combination of speed, precision, versatility and low cost makes it suitable as a general purpose comparator in analog signal processing and data acquisition systems. 2. Built-in hysteresis and a low-glitch output stage minimize the chance of unwanted oscillations, making the AD790 easier to use than standard open-loop comparators. 3. The hysteresis combined with a wide input voltage range enables the AD790 to respond to both slow, low level (e.g., 10 mV) signals and fast, large amplitude (e.g., 10 V) signals. 4. A wide variety of supply voltages is acceptable for operation of the AD790, ranging from single 5 V to dual +5 V/–12 V, ± 5 V, or +5 V/± 15 V supplies. 5. The AD790’s power dissipation is the lowest of any comparator in its speed range. 6. The AD790’s output swing is symmetric between VLOGIC and ground, thus providing a predictable output under a wide range of input and output conditions. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 2002 AD790–SPECIFICATIONS DUAL SUPPLY Parameter RESPONSE CHARACTERISTIC Propagation Delay, tPD OUTPUT CHARACTERISTICS Output HIGH Voltage, VOH (Operation @ 25 C and +VS = 15 V, –VS = –15 V, VLOGIC = 5 V unless otherwise noted.) Conditions 100 mV Step 5 mV Overdrive TMIN to TMAX 1.6 mA Source 6.4 mA Source TMIN to TMAX 1.6 mA Sink 6.4 mA Sink TMIN to TMAX Min AD790J/A Typ Max 40 45 45/50 Min AD790K/B Typ Max 40 45 45/50 AD790S Min Typ Max 40 45 60 Unit ns ns Output LOW Voltage, VOL 4.65 4.3 4.45 4.3/4.3 0.35 0.44 4.3 4.3 0.5 0.5/0.5 1.0 1.5 0.6 5 6.5 0.25 0.3 4.65 4.45 0.35 0.44 4.3 4.3 0.5 0.5 0.25 0.5 0.5 3.5 4.5 0.15 0.2 4.65 4.45 0.35 0.44 0.5 0.5 1.0 1.5 0.65 5 7 0.25 0.4 V V V V V mV mV mV µA µA µA µA dB dB INPUT CHARACTERISTICS Offset Voltage1 Hysteresis2 Bias Current Offset Current TMIN to TMAX Power Supply Rejection Ratio DC Input Voltage Range Differential Voltage Common Mode Common Mode Rejection Ratio VS ± 20% TMIN to TMAX VS ≤± 15 V –VS –10 V