Diodes Incorporated ZABG4002JA16TC

Overview

ZABG4002JA16TC from Diodes Incorporated is a four-stage depletion-mode GaAs FET bias controller for satellite LNBs and microwave LNAs, delivering independent -2.5V gate bias and 2.0V regulated drain voltage per stage, with user-programmable drain current (0–15 mA per pair), 1.2 mA typical quiescent supply current, and operation from 3.0V to 8.0V supply - deployed in twin/quad LNB systems requiring stable low-noise front-end biasing.

For engineers reviewing the ZABG4002JA16TC datasheet, ZABG4002JA16TC pinout, ZABG4002JA16TC application, or ZABG4002JA16TC equivalent, this device supports dual-pair programmable current biasing, integrated -2.5V negative supply generation, temperature-stable V_D and I_D, power-up/down FET protection, and QFN1633 footprint optimization for space-constrained RF modules.

Technical Context

The ZABG4002 implements two independent RCAL-controlled current regulation loops: RCAL1 sets I_D for stages 1 & 3 (e.g., low-noise input FETs), RCAL2 sets I_D for stages 2 & 4 (e.g., gain-optimized amplifier FETs), each with ±0.05%/°C I_D drift and ±50 ppm/°C V_D drift. All drain outputs are regulated at 2.0V ±0.2V with built-in current limiting (~5% above setpoint).

Its on-chip switched-capacitor DC-DC converter generates a stable -2.5V substrate voltage (V_CSUB) from a single positive supply, enabling grounded-source depletion-mode FET biasing without external negative rails; RCAL pins double as logic-disable inputs (>3.0V disables associated pair, forcing gate to -2.5V and drain open-circuit).

Key Specifications

Pinout & Package

Package: 16-pin QFN1633 (3 mm × 3 mm, 0.5 mm pitch), exposed thermal pad (to be left floating or connected to CSUB).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZABG4003JA16TC, this part offers identical functional capability but lower ESD robustness and looser V_D tolerance; versus MAX2641, it provides true four-stage programmable biasing and external -2.5 V availability - making it uniquely suited for multi-output satellite LNBs requiring independent noise/gain optimization.

Availability

ZABG4002JA16TC is available at Aetrix Electronics and suitable for twin LNBs, quad LNBs, and microwave point-to-point links requiring stable component supply, long-term obsolescence management, and RoHS-compliant QFN packaging.

Supply support for ZABG4002JA16TC 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and precision analog solutions for industrial, communications, and consumer markets.

The ZABG series targets satellite LNB and microwave LNA biasing, designed to replace discrete resistor-diode-zener networks with integrated, thermally stable, low-noise current regulation and on-chip negative voltage generation.

FAQ

What external components are mandatory for ZABG4002JA16TC operation?

Four external components are required: two 47 nF capacitors (CNB and CSUB) for the internal -2.5 V charge pump, and two RCAL resistors (e.g., 39 kΩ for 10 mA) to set drain currents for FET pairs 1&3 and 2&4. Gate and drain bypass capacitors (10 nF each per stage) are recommended for RF stability and noise suppression.

Can unused bias stages be left unconnected?

Yes. Unused Gx and Dx pins may be left open-circuit without affecting operation of remaining stages. If an entire RCAL-controlled pair is unused (e.g., stages 2&4), the corresponding RCAL resistor may be omitted. The exposed QFN pad must remain floating or connect to CSUB - never to GND or VCC.

How does the ZABG4002 handle power-up sequencing with external FETs?

The device incorporates intrinsic power-up protection: gate drivers are slew-rate limited and clamped to -3.0 V maximum, while drain supplies ramp under current limit. No external sequencing circuitry is needed - FETs receive controlled bias before full VCC stabilization, preventing gate oxide stress or thermal runaway.

Is the -2.5 V output at CSUB rated for external load current?

Yes. The CSUB pin delivers the regulated -2.5 V output from the internal charge pump and can source up to 200 µA (per datasheet V_CSUB(L) test condition). It is commonly used to bias external mixers, local oscillators, or additional discrete FET stages - provided total load stays within specified current limits.