Infineon Technologies BB689H7902XTSA1

Overview

BB689H7902XTSA1 from Infineon Technologies is a silicon tuning diode (varactor) designed for VHF TV tuner front-end voltage-controlled oscillator (VCO) and RF filter tuning circuits. It delivers a capacitance range of 2.5–61.5 pF at 1 MHz, 18–23.2× capacitance ratio (1 V / 28 V), and low series resistance of 0.85 Ω (typ.) at 470 MHz - enabling high-Q resonant tank performance in compact broadcast receiver modules.

For engineers reviewing the BB689H7902XTSA1 datasheet, BB689H7902XTSA1 pinout, BB689H7902XTSA1 application, or BB689H7902XTSA1 equivalent, key selection criteria include reverse voltage rating (30 V), temperature coefficient of capacitance, matching tolerance (±2 % across 7-diode sequence), and SC79 package compatibility with high-frequency PCB layout constraints.

Technical Context

This varactor operates under reverse-bias conditions only, where junction capacitance varies nonlinearly with applied DC tuning voltage (0–28 V). Its "in-line" matching assembly ensures tight inter-device capacitance tracking across production lots - critical for multi-stage VCOs requiring phase coherence.

The diode exhibits a typical series inductance of 0.6 nH and temperature coefficient of capacitance (TCC) ranging from –10⁻⁴ to –10⁻³ /°C depending on bias point, supporting stable frequency drift compensation in consumer-grade VHF tuners operating from –55 °C to +150 °C.

Key Specifications

Pinout & Package

BB689H7902XTSA1 is housed in an SC79 (SOD-523) surface-mount package: 1.3 mm × 0.7 mm × 0.6 mm, cathode-marked with laser dot on top surface, optimized for RF layout with minimal parasitic inductance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar varactor diode applications.

Compared with BB689H7901XTSA1 and BB669H7902XTSA1, BB689H7902XTSA1 provides the widest VHF tuning range and lowest series resistance - making it optimal for high-fidelity broadcast tuner designs demanding minimal frequency drift and best-in-class phase noise.

Availability

BB689H7902XTSA1 is available at Aetrix Electronics and suitable for VHF TV tuners, FM radio front-ends, automotive diversity receivers, and legacy cable TV descrambler modules requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for BB689H7902XTSA1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies AG is a German semiconductor manufacturer specializing in power management, RF, and automotive ICs, with global R&D and manufacturing infrastructure.

BB689H7902XTSA1 belongs to Infineon's BB6xx silicon tuning diode product line, engineered specifically for high-reliability analog RF tuning in broadcast and communications equipment where capacitance stability and matching are critical.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The absolute maximum DC reverse voltage is 30 V at 25 °C, with peak reverse voltage rated at 35 V when series resistance is ≤ 5 kΩ. Operation above 30 V risks irreversible junction breakdown, especially at elevated temperatures (> 85 °C), where leakage current rises significantly - derating to 25 V is advised for 150 °C ambient designs.

How does capacitance matching impact multi-diode VCO designs?

With ±2 % capacitance matching across a 7-diode sequence at all bias points (1–28 V), BB689H7902XTSA1 enables predictable parallel/series varactor arrays without per-unit calibration. This reduces production test time and improves yield in dual-conversion tuners requiring matched I/Q LO paths or image-reject architectures.

Can this diode be used in S-band (2–4 GHz) applications?

No - its 0.6 nH series inductance and rising series resistance above 500 MHz limit effective use to ≤ 250 MHz. Measured capacitance roll-off and Q degradation begin at ~300 MHz; for S-band, GaAs or silicon-on-insulator (SOI) varactors with sub-0.2 nH LS are required.

Is the SC79 package compatible with standard reflow profiles for lead-free assembly?

Yes - the Pb-free SC79 package is qualified for IPC/JEDEC J-STD-020D-compliant lead-free reflow, with peak temperature up to 260 °C for 30 seconds. Thermal mass is low (0.6 mm height), enabling uniform heating; no special preheat or soak profile is needed beyond standard SnAgCu ramp rates.