1. General Information

️· Manufacturer: Microsemi (now Microchip)
️· Series: Silicon Zener Diodes (500mW)
️· Part Number Range: 1N4370 - 1N759, including variants with the '-1' suffix.
️· Package Type: DO-35
️· Revision: 10-31-2003 REV B

2. Electrical Characteristics (Key Data)

The table lists electrical characteristics for various zener diodes within the range. Here's a summary of the columns and example data. Note that values change depending on the part number.

️· JEDEC Type No.: Identifies the diode (e.g., 1N4370, 1N746).
️· Nominal Zener Voltage (Vz @ Izt): The target zener voltage at a specified test current (IzT).
️· Zener Test Current (IzT): Current at which the zener voltage is measured. Usually 20mA for these parts.
️· Maximum Zener Impedance (Zzt @ Izt): The zener diode's impedance at the test current.
️· Maximum Reverse Current (Ir) @ Vr = 1V: The maximum reverse current at a low reverse voltage. Values provided at both 25°C and +150°C.
️· Maximum Zener Current (I zm): Maximum allowable zener current.
️· Typical Temp. Coefficient of Zener Voltage (α Vz): How much the zener voltage changes with temperature (% / °C).

Here's a simplified example of some of the data:

Part Number	Nominal Vz (Volts)	Temp. Coefficient (%) / °C
1N4370	2.4	-0.085
1N746	3.3	-0.066
1N749	4.3	-0.033
1N753	6.2	+0.049
1N757	9.1	+0.061

3. Notes & Considerations

️· Standard Tolerance: JEDEC standard tolerance is +/- 10%. Suffix 'A' indicates +/- 5%, 'C' indicates +/- 2%, and 'D' indicates +/- 1%.
️· Temperature Effects: The temperature coefficient (α Vz) is crucial. It indicates how much the zener voltage will change with temperature fluctuations. A negative coefficient means the voltage decreases as temperature increases.
️· Zener Impedance: Important for circuit design where the diode's impedance needs to be considered.
️· Power Dissipation: The datasheet mentions 500mW, implying a maximum power dissipation limit. This would need to be adhered to prevent damage.

4. Diagrams/Figures

️· Figure 1 & 2: Power Derating Curve and Zener Voltage Temperature Coefficient graph.
️· Figure 3: Package dimensions.