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REV. 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. a Fast, Precision Comparator AD790

FEATURES

45 ns max Propagation Delay Single 5 V or Dual /H1155015 V Supply Operation CMOS or TTL Compatible Output 250 /H9262V max Input Offset Voltage 500 /H9262V max Input Hysteresis Voltage

15 V max Differential Input Voltage

Available in 8-Pin Plastic and Hermetic Cerdip Packages Available in Tape and Reel in Accordance with EIA-481A Standard

APPLICATIONS

Delta-Sigma Modulator A/Ds PRODUCT DESCRIPTION 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 in- put 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 tem- perature 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. PRODUCT HIGHLIGHTS 1. The AD790’s combination of speed, precision, versatility and low cost makes it suitable as a general purpose compara- tor 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 compara- tor in its speed range. 6. The AD790’s output swing is symmetric between V LOGIC and ground, thus providing a predictable output under a wide range of input and output conditions. CONNECTION DIAGRAMS 8-Pin Plastic Mini-DIP (N) and Cerdip (Q) Packages OUTPUT LATCH GROUND VLOGIC1 AD790 +VS +IN –IN –VS 8-Pin SOIC (R) Package LATCH GROUND VLOGIC +VS 4 5 8OUTPUT AD790 + – +IN –IN –VS Tel: 781/329-4700www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 2002

REV. D–2– AD790–SPECIFICATIONS DUAL SUPPLY AD790J/A AD790K/B AD790S Parameter Conditions Min Typ Max Min Typ Max Min Typ Max Unit RESPONSE CHARACTERISTIC 100 mV Step Propagation Delay, t PD 5 mV Overdrive 40 45 40 45 40 45 ns TMIN to TMAX 45/50 45/50 60 ns OUTPUT CHARACTERISTICS Output HIGH Voltage, V OH 1.6 mA Source 4.65 4.65 4.65 TMIN to TMAX 4.3/4.3 4.3 4.3 V Output LOW Voltage, V OL 1.6 mA Sink 0.35 0.35 0.35 V TMIN to TMAX 0.5/0.5 0.5 0.5 V INPUT CHARACTERISTICS TMIN to TMAX 1.5 0.5 1.5 mV Bias Current Either Input 2.5 5 1.8 3.5 2.5 5 µA TMIN to TMAX 6.5 4.5 7 µA TMIN to TMAX 0.3 0.2 0.4 µA Power Supply Rejection Ratio DC V S ±20% 80 90 88 100 80 90 dB TMIN to TMAX 76 88 85 93 76 85 dB Input Voltage Range Differential Voltage V S ≤± 15 V /H11550VS /H11550VS /H11550VS V Common Mode –V S +VS–2 V –V S +VS–2 V –V S +VS–2 V V Common Mode Rejection Ratio –10 V<V CM 80 95 88 105 80 95 dB <+10 V TMIN to TMAX 76 90 85 100 76 88 dB Input Impedance 20 /H2064822 0 /H2064822 0 /H206482M Ω/H20648pF LATCH CHARACTERISTICS Latch Hold Time, t H 25 35 25 35 25 35 ns Latch Setup Time, t S 51 0 51 0 51 0 n s LOW Input Level, V IL TMIN to TMAX 0.8 0.8 0.8 V HIGH Input Level, V IH TMIN to TMA X 1.6 1.6 1.6 V Latch Input Current 2.3 5 2.3 3.5 2.3 5 µA TMIN to TMAX 7 58 µA SUPPLY CHARACTERISTICS Diff Supply Voltage 3 VLOGIC = 5 V TMIN to TMAX 4.5 33 4.5 33 4.7 33 V Logic Supply T MIN to TMAX 4.0 7 4.0 7 4.2 7 V Quiescent Current +VS +VS = 15 V 8 10 8 10 8 10 mA –VS –VS = –15 V 4 5 4 5 4 5 mA VLOGIC VLOGIC = 5 V 2 3.3 2 3.3 2 3.3 mA Power Dissipation 242 242 242 mW TEMPERATURE RANGE Rated Performance T MIN to TMAX 0 to 70/–40 to +85 0 to 70/–40 to +85 –55 to +125 °C NOTES 1Defined as the average of the input voltages at the low to high and high to low transition points. Refer to Figure 6. 2Defined as half the magnitude between the input voltages at the low to high and high to low transition points. Refer to Figure 6. 3+VS must be no lower than (V LOGIC –0.5 V) in any supply operating conditions, except during power up. All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at final test. Specifications subject to change without notice. (Operation @ 25/H11543C and +VS = 15 V, –V S = –15 V, V LOGIC = 5 V unless otherwise noted.)

Parameter Conditions Min Typ Max Min Typ Max Min Typ Max Unit RESPONSE CHARACTERISTIC 100 mV Step Propagation Delay, t PD 5 mV Overdrive 45 50 45 50 45 50 ns TMIN to TMAX 50/60 50/60 65 ns OUTPUT CHARACTERISTICS Output HIGH Voltage, V OH 1.6 mA Source 4.65 4.65 4.65 TMIN to TMAX 4.3 4.3 4.3 V Output LOW Voltage, V OL 1.6 mA Sink 0.35 0.35 0.35 V TMIN to TMAX 0.5 0.5 0.5 V INPUT CHARACTERISTICS TMIN to TMAX 2.0 0.85 2.0 mV Bias Current Either Input 2.7 5 2.0 3.5 2.7 5 µA TMIN to TMAX 7 58 µA TMIN to TMAX 0.3 0.2 0.4 µA Power Supply Rejection Ratio DC 4.5 V ≤VS≤5.5 V 80 90 86 100 80 90 dB TMIN to TMAX 76/76 88 82 93 76 85 dB Input Voltage Range Differential Voltage /H11550VS /H11550VS /H11550VS V Common Mode 0 +V S–2 V 0 +V S–2 V 0 +V S–2 V V Input Impedance 20 /H2064822 0 /H2064822 0 /H206482M Ω/H20648pF LATCH CHARACTERISTICS Latch Hold Time, t H 25 35 25 35 25 35 ns Latch Setup Time, t S 51 0 51 0 51 0 n s LOW Input Level, V IL TMIN to TMAX 0.8 0.8 0.8 V HIGH Input Level, V IH TMIN to TMAX 1.6 1.6 1.6 V Latch Input Current 2.3 5 2.3 3.5 2.3 5 µA TMIN to TMAX 7 58 µA SUPPLY CHARACTERISTICS Supply Voltage 4 TMIN to TMAX 4.5 7 4.5 7 4.7 7 V Quiescent Current 10 12 10 12 10 12 mA Power Dissipation 60 60 60 mW TEMPERATURE RANGE Rated Performance T MIN to TMAX 0 to 70/–40 to +85 0 to 70/–40 to +85 –55 to +125 °C NOTES 1Pin 1 tied to Pin 8, and Pin 4 tied to Pin 6. 2Defined as the average of the input voltages at the low to high and high to low transition points. Refer to Figure 6. 3Defined as half the magnitude between the input voltages at the low to high and high to low transition points. Refer to Figure 6. 4–VS must not be connected above ground. All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at final test. Specifications subject to change without notice. AD790 REV. D –3– (Operation @ 25/H11543C and +VS = VLOGIC = 5 V, –V S = 0 V unless otherwise noted.) 1

TPC 2. Propagation Delay vs. TPC 5. Propagation Delay vs. TPC 8. Total Supply Current vs. TPC 3. Propagation Delay vs. TPC 6. Output Low Voltage vs. Figure 4. Latch Timing TPC 1. Propagation Delay vs. TPC 4. Propagation Delay vs. TPC 7. Output High Voltage vs.

LOWER THE MAXIMUM USABLE CLOCK RATE. Figure 11. A Bipolar to CMOS TTL Line Receiver (N, Q ence voltage level about which the line receiver would switch. around this level and produces a CMOS/TTL compatible swing. The circuit will operate to switching frequencies of 20 MHz.

REV. D –9– OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 8-Pin Plastic Mini-DIP (N-8) Package 8-Pin Cerdip (Q-8) Package SOIC (R-8) Package 0.25 (0.0098) 0.19 (0.0075) 1.27 (0.0500) 0.41 (0.0160) 0.50 (0.0196) 0.25 (0.0099) /H11547 45/H11543 8/H11543 0/H11543 1.75 (0.0688) 1.35 (0.0532) SEATING PLANE 0.25 (0.0098) 0.10 (0.0040) 5.00 (0.1968) 4.80 (0.1890) PIN 1 0.1574 (4.00) 0.1497 (3.80) 1.27 (0.0500) BSC 6.20 (0.2440) 5.80 (0.2284) 0.51 (0.0201) 0.33 (0.0130) COPLANARITY CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MS-012 AA

REV. D–10–

Revision History

Data Sheet changed from REV. C to REV. D. 03/02— Data Sheet changed from REV. B to REV. C.

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C00844–0–5/02(D) PRINTED IN U.S.A. –12–