Resistor-programmable logic-output temperature switches

The low-power devices' temperature-switch threshold can be programmed with a single external resistor, meaning designers can stock one device for measuring multiple temperature points by varying the external resistance value. With an operating voltage range of 2.7V to 5.5V and the ability to trigger for temperatures ranging from –40 to +125°C with high accuracy, the MCP9509/10 switches enable better, smaller and less expensive designs.

Many applications require monitoring multiple temperature points within the system. The MCP9509/10 switches monitor temperature based upon user-programmed resistance values. When the programmed temperature threshold is reached, the switches alert the system and the system can react accordingly.

User-programmable features, such as 2°C and 10°C (typical) switch hysteresis and output-structure configuration, mean the switches simplify designs and provide more flexibility to the designer.

The MCP9509 has a low static operating current of just 30 micro Amperes and provides an open-drain output; while the MCP9510 has a static operating current of only 50 micro Amperes and is offered in three different user-selectable output configurations — active-low push pull, active-high push pull, and active-low open-drain output with an internal 100 kilo Ohm pull-up resistor.

The MCP9509/10 switches are well-suited for battery-powered applications in the industrial (power supplies, wireless handsets and meters, multimeters); automotive (engine-temperature monitoring); medical (pharmaceutical storage-environment temperature control, refrigeration control); appliance (refrigerators and freezers), and consumer markets (PCs and peripherals).

Packaging, pricing, and availability
The MCP9509 temperature switches are available in a 5-pin SOT-23 package; the MCP9510 in a 6-pin SOT-23 package. Both devices are priced at $0.61 each, in 10,000-unit quantities. Samples can be ordered today at http://sample.microchip.com; volume-production quantities can be ordered today at www.microchipdirect.com.