MMBV2108LT1

Overview

The MMBV2108LT1 is a silicon tuning diode from the MMBV2101LT1 series, designed for FM radio and TV tuning applications. It operates in an SOT-23 package with a maximum reverse voltage of 30 Vdc and forward current of 200 mAdc. The device provides a typical diode capacitance of 27 pF at 4.0 Vdc (range: 24.3–29.7 pF) and a minimum figure of merit of 300 at 50 MHz. Its tuning ratio ranges from 2.5 to 3.2, measured between 2.0 Vdc and 30 Vdc. The component supports junction temperatures up to +150°C and storage temperatures from -55°C to +150°C.

Feature Summary

• High Q factor for improved circuit performance
• Controlled and uniform tuning ratio
• Standard capacitance tolerance of 10%
• Solid-state reliability replacing mechanical tuning methods

Applications

• FM Radio tuning
• TV tuning
• Automatic Frequency Control (AFC)
• General frequency control and tuning

Procurement Notes

Verify the specific ordering suffix when purchasing. The 'T1' suffix indicates tape and reel packaging, while dropping it denotes bulk availability. Confirm Pb-free status by checking for the 'G' suffix or microdot marking on the component body. Ensure the requested part matches the exact series designation to guarantee correct electrical characteristics.

Selection Notes

Select this component based on required capacitance values and operating frequencies. Verify that the 30 Vdc reverse voltage rating meets the circuit's peak reverse bias requirements. Consider the thermal derating specifications if the ambient temperature exceeds 25°C. Compare the figure of merit against other series members to ensure adequate quality factor for the intended application.

Part Context

This device belongs to the MMBV2101LT1 series, which includes variants like MMBV2101LT1, MMBV2105LT1, and MMBV2109LT1. These parts share similar structural designs but differ in nominal capacitance values ranging from approximately 6.8 pF to 36.3 pF. The series is engineered for high-volume manufacturing and offers plastic package options suitable for surface mount and through-hole technologies.

Replacement Considerations

MMBV2109LT1

FAQ

How is the tuning ratio defined for this device?

The tuning ratio is defined as the ratio of diode capacitance measured at 2.0 Vdc divided by the capacitance measured at 30 Vdc.

What is the pin configuration for the SOT-23 package?

Pin 1 is the Anode, Pin 2 is No Connection, and Pin 3 is the Cathode.

How is the Figure of Merit (Q) calculated?

Q is calculated using G and C readings from an admittance bridge at the specified frequency, substituting them into the equation Q = ωC/G.