Octal Channel Protectors ADG467 FEATURES FUNCTIONAL BLOCK DIAGRAM V V DD SS Fault and overvoltage protection up to 40 V Signal paths open circuit with power off V V D1 S1 Signal path resistance of R with power on ON 44 V supply maximum ratings V V D2 S2 Low on resistance: 62 typical V V 1 nA maximum path current leakage +25C D3 S3 Low R match (5 maximum) ON Low power dissipation 0.8 W typical V V D8 S8 V IN V Latch-up proof construction OUT ADG467 V V IN OUT APPLICATIONS ATE equipment Sensitive measurement equipment V V DD DD Hot insertion rack systems OUTPUT CLAMPED AT V 1.5V DD Figure 1. GENERAL DESCRIPTION The ADG467 is an octal channel protector. The channel connected and open circuit when power is disconnected. With protector is placed in series with the signal path. The channel power supplies of 15 V, the on resistance of the ADG467 is protector protects sensitive components from voltage transience 62 typical with a leakage current of 1 nA maximum. When in the signal path regardless if the power supplies are present or power is disconnected, the input leakage current is approx- imately 0.5 nA typical. not. For this reason, the channel protectors are ideal for use in applications where correct power sequencing cannot always be The ADG467 is available in an 18-lead SOIC package and a guaranteed (for example, hot insertion rack systems) to protect 20-lead SSOP package. analog inputs. This is described further, and some example PRODUCT HIGHLIGHTS circuits are given in the Applications Information section. 1. Fault Protection. Each channel protector has an independent operation and con- The ADG467 can withstand continuous voltage inputs sists of an N-channel MOSFET, a P-channel MOSFET, and an from 40 V to +40 V. When a fault occurs due to the N-channel MOSFET, connected in series. The channel protector power supplies being turned off or due to an overvoltage behaves just like a series resistor during normal operation, that being applied to the ADG467, the output is clamped. is, (VSS + 1.5 V) < VIN < (VDD 1.5 V). When a channels analog When power is turned off, current is limited to the input exceeds the power supplies (including VDD and VSS = 0 V), microampere level. one of the MOSFETs switches off, clamping the output to either 2. Low Power Dissipation. V + 1.5 V or V 1.5 V. Circuitry and signal source protec- SS DD 3. Low RON. 62 typical. tion is provided in the event of an overvoltage or power loss. 4. Trench Isolation Latch-Up Proof Construction. The channel protectors can withstand overvoltage inputs from A dielectric trench separates the p- and n-channel 40 V to +40 V. See the Circuit Information section. MOSFETs thereby preventing latch-up. The ADG467 can operate off both bipolar and unipolar supplies. The channels are normally on when power is Rev. B 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 08191-001ADG467 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................6 Applications....................................................................................... 1 Test Circuits........................................................................................8 Functional Block Diagram .............................................................. 1 Circuit Information...........................................................................9 General Description ......................................................................... 1 Overvoltage Protection.................................................................9 Product Highlights ........................................................................... 1 Trench Isolation.............................................................................. 11 Revision History ............................................................................... 2 Applications Information .............................................................. 12 Specifications..................................................................................... 3 Overvoltage and Power Supply Sequencing Protection........ 12 Dual Supply ................................................................................... 3 High Voltage Surge Suppression .............................................. 13 Absolute Maximum Ratings............................................................ 4 Outline Dimensions....................................................................... 14 ESD Caution.................................................................................. 4 Ordering Guide .......................................................................... 15 Pin Configuration and Function Descriptions............................. 5 REVISION HISTORY 2/11Rev. A to Rev. B Added Test Circuits Section and Figure 16 to Figure 20..............8 Updated Format..................................................................Universal Changes to Overvoltage Protection Section and Figure 23 .........9 Deleted ADG466 ................................................................Universal Changes to Figure 24...................................................................... 10 Changes to Features Section, General Description Section, Change to Figure 26 ....................................................................... 11 Figure 1, and Product Highlights Section ..................................... 1 Changes to Overvoltage and Power Supply Sequencing Changes to Power Requirements, V /V Parameter, Table 1... 3 Protection Section and Figure 27 ................................................. 12 DD SS Deleted 8-Lead DIP, SOIC, and SOIC Pin Configuration ........ 3 Changes to High Voltage Surge Suppression Section and Deleted Figure 12 Renumbered Sequentially .............................. 5 Figure 28 .......................................................................................... 13 Changes to Figure 4 to Figure 6...................................................... 6 Changes to Outline Dimensions .................................................. 14 Added Figure 7 Renumbered Sequentially .................................. 6 Changes to Ordering Guide .......................................................... 15 Changes to Figure 11 to Figure 15.................................................. 7 Rev. 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