Microchip Technology GC1311-154-4

Overview

GC1311-154-4 from Microsemi is a surface-mount hyperabrupt varactor diode optimized for voltage-controlled oscillators (VCOs) in microwave applications up to 6 GHz, featuring 6.8 pF capacitance at 4 V, 30 V reverse breakdown voltage, and Q ≥ 2300 at 4 V / 50 MHz. It operates from –55°C to +125°C and is RoHS-compliant with gold-finish ceramic/epoxy EPSM packaging.

For engineers reviewing the GC1311-154-4 datasheet, GC1311-154-4 pinout, GC1311-154-4 application, or GC1311-154-4 equivalent, key selection criteria include its C/V slope consistency across 0–30 V tuning range, low leakage (<50 nA at 80% VB), high Q factor for phase noise reduction, and compatibility with automated SMT assembly via 154-style footprint.

Technical Context

This device belongs to the GC1300 series of abrupt-junction varactors engineered for moderate-bandwidth, low-noise VCOs requiring stable capacitance ratio CT(0V)/CT(4V) ≥ 2.2 and CT(4V)/CT(30V) ≥ 2.05. Its hyperabrupt doping profile delivers predictable, monotonic C/V response ideal for linear frequency tuning.

Designed for zero-bias to 30 V operation, GC1311-154-4 exhibits minimal parasitic inductance and capacitance due to its EPSM 154 ceramic package - a flat-top, castellated surface-mount outline enabling reliable reflow soldering and RF performance up to 6 GHz without bond-wire inductance penalties.

Key Specifications

Pinout & Package

GC1311-154-4 uses the EPSM 154 surface-mount ceramic package: a two-terminal, flat-top, castellated outline with wrap-around metallization for robust solder joint reliability and low RF parasitics. Dimensions are 20±3 mils (W) × 120±5 mils (X) × 60±3 mils (Y) × 50 mils (Z) - equivalent to 0.508±0.076 mm × 3.048±0.127 mm × 1.524±0.076 mm × 1.270 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GC1310-154-4 and GC1312-154-4, GC1311-154-4 offers balanced capacitance and tuning ratio - optimizing trade-offs between VCO gain linearity, phase noise, and layout area in 1–3 GHz wireless transceivers.

Availability

GC1311-154-4 is available at Aetrix Electronics and suitable for GSM/PCS transceiver VCOs, wideband test equipment oscillators, voltage-tuned filters, and VCXO reference designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for GC1311-154-4 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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and timing solutions for aerospace, defense, communications, and industrial markets.

The GC1300 series - including GC1311-154-4 - was developed to replace legacy plastic-packaged varactors in microwave VCOs demanding low phase noise, high temperature stability, and consistent C/V repeatability across military and commercial production lots.

FAQ

What is the rated reverse breakdown voltage for GC1311-154-4?

The GC1311-154-4 has a minimum reverse breakdown voltage (VB) of 30 V at IR = 10 μA, verified per Microsemi's GC1300 series specification table. This rating allows safe operation across the full 0–30 V tuning range without risk of avalanche conduction, making GC1311-154-4 suitable for high-gain VCO designs requiring wide frequency coverage.

Does GC1311-154-4 require special PCB layout considerations for RF performance?

Yes - GC1311-154-4 benefits from symmetric, low-inductance pad design matching the 154 package's castellated terminals. Keep trace lengths to adjacent tank components under 1 mm, use solid ground plane beneath the device, and avoid vias near anode/cathode pads to preserve Q ≥ 2300 at 4 V / 50 MHz. The GC1311-154-4 datasheet specifies these guidelines for optimal VCO phase noise.

Is GC1311-154-4 compatible with lead-free reflow soldering profiles?

Yes - GC1311-154-4 features a RoHS-compliant gold finish on its EPSM 154 ceramic package and is qualified for JEDEC J-STD-020D-compliant lead-free reflow, including peak temperatures up to 260°C for 30 seconds. The GC1311-154-4 construction eliminates organic mold compounds that degrade under thermal stress, ensuring solder joint integrity in high-volume manufacturing.

How does the capacitance ratio CT(0V)/CT(4V) = ≥2.2 impact VCO design using GC1311-154-4?

A CT(0V)/CT(4V) ratio ≥2.2 means GC1311-154-4 delivers at least 100% relative capacitance change over the first 4 V of tuning voltage - enabling broader absolute frequency deviation in LC-tank VCOs without increasing inductor size. This ratio directly determines achievable K_VCO (MHz/V) in GC1311-154-4-based designs while maintaining monotonic tuning behavior.

Can GC1311-154-4 be used in common-cathode dual-varactor configurations?

No - GC1311-154-4 is a single two-terminal varactor in the 154 package. For common-cathode dual configurations, Microsemi specifies the 454-series packages (e.g., GC1303-454-4). The GC1311-154-4 pinout and mechanical outline do not support three-terminal operation; attempting such use would violate its specified terminal roles and degrade C/V repeatability.