Signal Line Circuit Protector with Three Independent Protectors

Please check latest availability status for a specific part variant.


The MAX366 and MAX367 are multiple, two-terminal circuit protectors. Placed in series with signal lines, each two-terminal device guards sensitive circuit components against voltages near and beyond the normal supply voltages. These devices are used at interfaces where sensitive circuits are connected to the external world and could encounter damaging voltages (up to 35V beyond the supply rails) during power-up, power-down, or fault conditions.

The MAX366 contains three independent protectors and the MAX367 contains eight. They can protect analog signals using either unipolar (4.5V to 36V) or bipolar (±2.25V to ±18V) power supplies. Each protector is symmetrical. Input and output terminals may be freely interchanged.

These devices are voltage-sensitive MOSFET transistor arrays that are normally on when power is applied and normally open circuit when power is off. With ±10V supplies, on-resistance is 100Ω max and leakage is less than 1nA at +25°C.

When signal voltages exceed or are within approximately 1.5V of either power-supply voltage (including when power is off), the two-terminal resistance increases dramatically, limiting fault current as well as output voltage to sensitive circuits. The protected side of the switch maintains the correct polarity and clamps approximately 1.5V below the supply rail. There are no "glitches" or polarity reversals going into or coming out of a fault condition.
MAX366, MAX367: Typical Operating Circuit MAX366, MAX367: Typical Operating Circuit Enlarge+

Key Features

  • ±40V Overvoltage Protection
  • Open Signal Paths with Power Off
  • 100Ω Signal Paths with Power On
  • 1nA Max Path Leakage at +25°C
  • 44V Maximum Supply Voltage Rating
  • Automatic Protection; No Programming or Controls


  • Automated Test Equipment (ATE)
  • Data Acquisition
  • Hot-Insertion Boards/Systems
  • Process Control Systems
  • Redundant/Backup Systems
  • Sensitive Instruments

See parametric specs for Signal-Line Protectors (6)

Part NumberFunctionsSignal Path Leakage
ΔRONAnalog Signal Range
Fault Protect.
(max)(Dual)(max)(See Notes)
MAX366 3-Line17-12.5 to +13.54.5 to 36.02.25 to 18.010040
SOIC (N)/8
$2.11 @1k
MAX367 8-Line
SOIC (W)/18
$3.23 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Request Reliability Report for: MAX366 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources