LTZ1000ACH

Overview

The LTZ1000ACH is an ultra-precision temperature-controlled voltage reference housed in an 8-lead TO-5 metal can. It provides a nominal 7V output with a typical temperature drift of 0.05ppm/°C and noise of 1.2µVP-P (0.1Hz to 10Hz). The device features long-term stability of 2µV/√kHr and includes an integrated heater resistor, subsurface zener, and temperature sensing transistor. The LTZ1000A variant utilizes a proprietary die attach method yielding a thermal resistance of 400°C/W, significantly reducing insulation requirements compared to the standard LTZ1000.

Feature Summary

• Integrated heater resistor and temperature sensing transistor for active thermal stabilization
• Subsurface zener reference providing low noise and high long-term stability
• Proprietary die attach method on LTZ1000A variant for enhanced thermal isolation

Applications

• High-accuracy voltmeters
• Precision calibrators
• Standard cells
• Low noise RF oscillators

Procurement Notes

Verify that the specific part number matches the required thermal resistance specification. The LTZ1000ACH designation indicates the A-version with higher thermal resistance. Confirm package type is the 8-lead TO-5 metal can. Ensure external circuitry supports the necessary heater control and proper thermal layout management to achieve specified performance levels.

Selection Notes

Select the LTZ1000ACH over the standard LTZ1000 when reduced insulation complexity is required due to its higher thermal resistance. Consider the need for external amplifier circuitry and careful PCB layout to mitigate thermocouple effects. Evaluate if the extreme precision justifies the design complexity compared to simpler references like the LT1021 or LM399A.

Part Context

Manufactured by Analog Devices Inc. (formerly Linear Technology), this component belongs to the LTZ1000 family of ultra-stable references. It is designed for applications demanding superior performance compared to older devices like the LM199. The device requires external components to set operating currents and stabilize temperature, offering maximum flexibility for optimal stability and noise characteristics.

Replacement Considerations

LTZ1000CH

FAQ

What is the primary difference between the LTZ1000 and LTZ1000A?

The LTZ1000A uses a proprietary die attach method that provides significantly higher thermal resistance (400°C/W) compared to the LTZ1000 (80°C/W), which reduces the insulation requirements.

How does the LTZ1000ACH handle thermocouple effects?

To minimize thermocouple effects from Kovar leads, the device requires careful PCB layout where zener and transistor leads are kept at the same temperature using equal-sized traces to prevent voltage shifts.