Datasheet AD8024 (Analog Devices) - 10

AD8024 Overload Recovery Disable Mode Operation
The most important overload conditions are: When the Disable pin is tied to DGND, all amplifiers are opera- tional, in the enabled state. Input Common-Mode Voltage Overdrive Output Voltage Overdrive When the voltage on the Disable pin is raised to 1.6 V or more Input Current Overdrive. above DGND, all amplifiers are in the disabled, powered-down state. In this condition, the DISABLE pin sources approximately When configured for a low closed-loop gain, the AD8024 0.1 µA, the total quiescent current is reduced to approximately recovers quickly from an input common-mode voltage over- 500 µA, all outputs are in a high impedance state, and there is a drive; typically in <25 ns. high level of isolation from inputs to outputs. When configured for a higher gain and overloaded at the output, The output impedance in the disabled mode is the equivalent of all recovery from an output voltage overdrive is also short; approxi- external resistors, seen from the output pin, in parallel with the mately 55 ns (see Figure 5). For higher overdrive, the response total disabled output impedance of the amplifier, typically 20 pF. is somewhat slower. For 100% overdrive, the recovery time is substantially longer. The input stages of the AD8024 include protection from large differential input voltages that may be present in the disabled When configured for a high noninverting gain, a high input over- mode. Internal clamps limit this voltage to 1.5 V. The high input- drive can result in a large current into the input stage. Although to-output isolation is maintained for voltages below this limit. this current is internally limited to approximately 30 mA, its effect on the total power dissipation may be significant. See also the warning under Maximum Power Dissipation.
1V 50ns VIN VOUT 5V
Figure 5. 15% Overload Recovery, Gain = +10 (RFB = 400 Ω, RL = 1 kΩ, VS = ±7.5 V) –10– REV. C