Microchip Technology GC1509-30

Overview

GC1509-30 from Microsemi is a silicon abrupt junction tuning varactor diode rated for 30 V breakdown, with nominal capacitance of 4.7 pF ±10% at −4 V, minimum Q of 2600 at 50 MHz, and capacitance ratio CT₀/CT₋₃₀ ≥ 3.9. It serves as a voltage-controlled reactance element in RF tuning circuits operating from VHF through Ku band.

For engineers reviewing the GC1509-30 datasheet, GC1509-30 pinout, GC1509-30 application, or GC1509-30 equivalent, key selection criteria include its low series resistance, high Q factor, tight capacitance tolerance, thermal coefficient of capacitance (300 ppm/°C), and suitability for low-phase-noise VCOs and voltage-variable filters.

Technical Context

The GC1509-30 is a single-junction silicon varactor optimized for abrupt C–V characteristics, enabling precise voltage-dependent capacitance control across −0.5 V to −30 V reverse bias. Its design targets minimal parasitic series resistance (Rs) and maximal quality factor (Q) at RF frequencies up to Ku band.

Capacitance is measured at 1 MHz with 0.18 pF case capacitance included; Q is specified at 50 MHz using transmission loss techniques at 1 GHz for Rs extraction. Thermal coefficient of capacitance is +300 ppm/°C at −4 V, supporting stable tuning in temperature-varying RF front-ends.

Key Specifications

Pinout & Package

GC1509-30 is supplied in Style 30 surface-mount package: ceramic chip with gold-plated terminations, dimensions 0.030" × 0.030" × 0.015" (0.76 mm × 0.76 mm × 0.38 mm), compliant with RoHS Directive 2002/95/EC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MA46H110 and SMV1232-079LF, GC1509-30 delivers superior Q and tighter capacitance tolerance in a miniature ceramic chip package-critical for space-constrained, low-phase-noise RF modules where bias headroom and thermal stability are prioritized.

Availability

GC1509-30 is available at Aetrix Electronics and suitable for VCO design, voltage-variable filter implementation, and phased-array phase shifter development requiring stable component supply and consistent RF performance across production lots.

Supply support for GC1509-30 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

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and timing solutions for aerospace, defense, and communications infrastructure.

The GC1500 series was engineered specifically for microwave tuning applications demanding high Q, low Rs, and stable C–V linearity from VHF through Ku band-addressing stringent phase noise and thermal drift requirements in military and SATCOM systems.

FAQ

What is the nominal capacitance and tolerance of GC1509-30?

The GC1509-30 has a nominal capacitance of 4.7 pF ±10% measured at −4 V reverse bias and 1 MHz, including 0.18 pF case capacitance. This tolerance supports predictable tuning range in production VCOs and filters without individual unit calibration.

Does GC1509-30 meet RoHS requirements?

Yes, GC1509-30 is RoHS compliant per EU Directive 2002/95/EC. It features gold-plated terminations as standard and operates across −55°C to +125°C, making it suitable for aerospace and industrial environments where regulatory compliance is mandatory.

What is the maximum operating voltage for GC1509-30?

The GC1509-30 has a minimum breakdown voltage of 30 V at 10 µA leakage, allowing safe operation up to −28 V DC reverse bias in practical RF tuning circuits. Exceeding this risks irreversible junction damage and parametric shift.

How does the thermal coefficient of capacitance affect GC1509-30 in real designs?

The GC1509-30 exhibits a thermal coefficient of +300 ppm/°C at −4 V, meaning capacitance increases by 0.03% per °C rise. In a 10°C ambient shift, this causes ~0.3% C change-requiring compensation in narrowband VCOs but negligible in broadband tuners.

Is GC1509-30 suitable for Ku-band applications?

Yes, GC1509-30 is explicitly characterized for Ku-band use: its 2600 Q at 50 MHz scales favorably to higher frequencies, and its abrupt junction enables stable C–V response up to 18 GHz. Microsemi's application notes confirm validated use in 12–18 GHz VCOs and phase shifters.