ADG465 Single Channel Protector in an SOT-23 Package and a MSOP Package
The ADG465 is a single channel protector that comes in SOT-23 and MSOP packages. The channel protector is in series with the signal path and protects sensitive components from voltage transience in the signal path whether or not the power supplies are present. Because the channel protection works regardless of the presence of the supplies, the channel protectors are ideal for use in applications where correct power sequencing cannot always be guaranteed to protect the analog inputs (for example, hot insertion rack systems).
A channel protector consists of an N channel, metal-oxide semiconductor field-effect transistor (MOSFET), a P channel MOSFET, and another N channel MOSFET connected in series. The channel protector behaves like a series resistor during normal operation, that is, (VSS + 1.5 V) < VIN < (VDD − 1.5 V). When the analog input of a channel exceeds the power supplies (including VDD and VSS = 0 V), one of the MOSFETs switches off, clamping the output to either VSS + 1.5 V or VDD − 1.5 V. Circuitry and signal source protection are provided in the event of an overvoltage or power loss. The channel protectors can withstand overvoltage inputs from −40 V to +40 V.
The ADG465 can operate from both bipolar and unipolar supplies. The channels are normally on when power is connected, and open circuit when power is disconnected. With power supplies of ±15 V, the on resistance of the ADG465 is 80 Ω typical, with a leakage current of ±1 nA maximum. When power is disconnected, the input leakage current is approximately ±0.005 μA typical. The ADG465 is available in a 6-lead SOT-23 package, and an 8-lead MSOP package.
- Fault Protection.
The ADG465 can withstand continuous voltage inputs from −40 V to +40 V. When a fault occurs due to the power supplies being turned off, or due to an overvoltage being applied to the ADG465, the output is clamped. When power is turned off, current is limited to the nanoampere level.
- Low Power Dissipation.
- Low RON 80 Ω typical.
- Trench Isolation Latch-Up Proof Construction.
A dielectric trench separates the P channel and the N channel MOSFETs thereby preventing latch up.
- ATE Equipment
- Sensitive measurement equipment
- Hot insertion rack systems
- ADC input channel protection
Features and Benefits
- Fault and overvoltage protection up to ±40 V
- Signal paths open circuit with power off
- Signal path resistance of RON with power on
- Supply maximum ratings (VDD to VSS): 44 V
- Low on resistance (RON): 80 Ω typical
- ±1 nA maximum path current leakage at 25°C
- Low power dissipation: 0.8 μW typical
- Latch-up proof construction