ADG467BRZ

The ADG467 is an 8-channel protector. The channel protector is placed in series in the signal path. Regardless of whether power is present, the channel protector protects sensitive components in the signal path from voltage transients. Therefore, these channel protectors are well suited for applications where correct power sequencing cannot always be guaranteed (e.g., hot-swappable rack systems) to protect analog inputs. This is described further below, and example circuits are provided in the Application Information section. Each channel protector operates independently and consists of an N-channel MOSFET, a P-channel MOSFET, and another N-channel MOSFET connected in series. During normal operation, the channel protector behaves like a series resistance, i.e., (VSS + 1.5 V < VIN < VDD - 1.5 V). When the analog input on a channel exceeds the supply (including VDD and VSS = 0 V), one of the MOSFETs turns off, clamping the output to VSS + 1.5 V or VDD - 1.5 V. Circuit and signal source protection is provided under overvoltage or power loss conditions. The channel protector can withstand overvoltage inputs from -40 V to +40 V. See the Circuit Information section. The ADG467 can operate from both bipolar and unipolar supplies. When power is connected, the channel is normally on; when power is disconnected, the channel is open. At ±15 V supplies, the ADG467 has a typical on-resistance of 62 Ω and a maximum leakage current of ±1 nA. When power is disconnected, the input leakage current is approximately ±0.5 nA (typical). The ADG467 is available in an 18-pin SOIC package and a 20-pin SSOP package.

Applications

• Automatic Test Equipment (ATE)
• Sensitive measurement equipment
• Hot-swap rack systems

Key features

• Fault and overvoltage protection up to ±40 V
• Signal path open when power is off
• Signal path resistance Ron when powered on
• Maximum supply voltage 44 V
• Low on-resistance: typical 62 Ω
• Maximum path current leakage ±η nA
• Low Ron matching at 25°C (5 Ω max)
• Low power consumption: typical 0.8 μW
• Latch-up proof construction
• Supports continuous voltage input from -40 V to +40 V
• Current limited to microampere level when power is off
• Trench isolation latch-up proof construction