Diodes Incorporated ZNBG4001Q16

Overview

ZNBG4001Q16 from Zetex plc is a quad-channel GaAs/HEMT FET bias controller in QSOP16 package, generating regulated -3 V negative rail and 2.0 V drain voltage per channel from a single 5–12 V supply. It provides individual drain current control (0–15 mA per FET) via two external resistors (RCAL1/RCAL2), supports grounded-source FETs in satellite LNBs, and features dynamic gate voltage limiting (-3.5 V to 0.7 V) and fault-induced drain shutdown.

For engineers reviewing the ZNBG4001Q16 datasheet, ZNBG4001Q16 pinout, ZNBG4001Q16 application in LNB biasing, or ZNBG4001Q16 equivalent for GaAs FET bias control, this page delivers verified functional specifications, validated pin functions, real-world RF-stable implementation details, and confirmed alternatives with documented electrical and application-level differences.

Technical Context

The ZNBG4001Q16 integrates four independent bias stages sharing a common on-chip oscillator-based negative rail generator (−3 V, ±0.5 V), each with dedicated drain voltage regulation (2.0 V ±0.2 V) and gate drive circuitry. Drain current is set per pair via RCAL1 (FETs 1&2) and RCAL2 (FETs 3&4), with internal current-sense amplifiers maintaining stability across −40°C to +70°C.

It employs external 47 nF capacitors (CNB/CSUB) for negative rail generation and requires 4.7 nF (gate) and 10 nF (drain) RF decoupling per stage to ensure unconditional stability and sub-20 mV_pk-pk noise injection. Gate output compliance is hard-clamped between −3.5 V and +0.7 V under all transients, including power-up/down.

Key Specifications

Pinout & Package

Package: QSOP16 (4.85 mm × 3.90 mm × 1.40 mm body, 0.635 mm pitch), lead-free compatible, surface-mount.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FET bias control applications.

Compared with ZNBG4000Q16, the ZNBG4001Q16's lower 2.0 V drain voltage better suits ultra-low-noise GaAs FETs in LNB front-ends, while MAX2640 offers integration at the cost of flexibility and multi-stage bias control - making ZNBG4001Q16 optimal for RF designers needing precise, scalable, and fault-protected biasing.

Availability

ZNBG4001Q16 is available at Aetrix Electronics and suitable for satellite LNB manufacturing, PMR radio production, and cellular base station receiver assembly requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ZNBG4001Q16 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

Zetex plc (now part of Diodes Incorporated) is a UK-based analog semiconductor specialist focused on high-performance discrete and analog ICs for RF, power management, and precision signal conditioning.

The ZNBG series was designed specifically for GaAs/HEMT FET biasing in satellite and wireless infrastructure, emphasizing RF stability, thermal robustness, and minimal external component count in harsh environmental deployments.

FAQ

What external components are mandatory for ZNBG4001Q16 operation?

The ZNBG4001Q16 requires four mandatory external components: two 47 nF capacitors (CNB and CSUB) for internal negative rail generation, plus two gate-decoupling capacitors (4.7 nF each) and two drain-decoupling capacitors (10 nF each) - one set per active channel. RCAL1 and RCAL2 resistors are required only if drain current control is needed.

Can unused channels be left unconnected without affecting others?

Yes. Unused drain (Dx) and gate (Gx) pins may be left open-circuit with no impact on remaining active channels. The internal bias circuitry for disconnected channels is automatically disabled. However, RCAL1 and RCAL2 must remain connected to ground (via resistors or short) even if only one pair is used - floating RCAL inputs cause undefined current regulation.

How does the ZNBG4001Q16 protect external FETs during power-up?

During power-up, the ZNBG4001Q16 ensures gate outputs never exceed −3.5 V to +0.7 V by actively clamping with internal circuitry - preventing gate oxide stress. Simultaneously, the drain outputs (D1–D4) remain at 0 V until the internal oscillator stabilizes and the negative rail reaches −2.5 V, delaying FET conduction until full regulation is achieved.

Is the −3 V CSUB rail capable of powering external circuitry?

Yes - the CSUB pin delivers up to 200 µA of regulated −3 V current and can power auxiliary circuits such as mixer bias networks or IF amplifier references. However, loading beyond 200 µA risks destabilizing the internal oscillator and degrading gate drive accuracy; for higher loads, an external charge-pump regulator should be used.