INA330

• OPTIMIZED FOR PRECISION 10k THERMISTOR APPLICATIONS
  • LOW OFFSET OVER TEMPERATURE:
       0.009°C Temperature Error, –40°C to +85°C
  • EXCELLENT LONG-TERM STABILITY
  • VERY LOW 1/f NOISE: (0.01Hz to 10Hz)
       (Peak-to-Peak Equivalent to 0.0001°C)
• WIDE OUTPUT SWING: Within 10mV of Rails
• SUPPLY RANGE: Single +2.7V to +5.5V
• microPACKAGE: MSOP-10
• REQUIRES ONLY ONE PRECISION RESISTOR
• APPLICATIONS
  • THERMISTOR-BASED TEMPERATURE CONTROLLERS FOR OPTICAL NETWORKING
  • HIGH ACCURACY FOR TEC APPLICATIONS
  • LASER TEMPERATURE CONTROL

The INA330 is a precision amplifier designed for thermoelectric cooler (TEC) control in optical networking applications. It is optimized for use in 10k thermistor-based temperature controllers. The INA330 provides thermistor excitation and generates an output voltage proportional to the difference in resistances applied to the inputs. It uses only one precision resistor plus the thermistor, thus providing an alternative to the traditional bridge circuit. This new topology eliminates the need for two precision resistors while maintaining excellent accuracy for temperature control applications.

An excitation voltage is applied to the thermistor (R_THERM) and precision resistor (R_SET), creating currents I₁ and I₂. The current conveyor circuit produces an output current, I₀, equal to I₁ – I₂, which flows through the external gain-setting resistor. A buffered voltage output proportional to I₀ is also provided.

The INA330 offers excellent long-term stability, and very low 1/f noise throughout the life of the product. The low offset results in a 0.009°C temperature error from –40°C to +85°C. It comes in MSOP-10 packaging and operates with supply voltages from +2.7V to +5.5V. It is specified over the industrial temperature range, –40°C to +85°C, with operation from –40°C to +125°C.