Renesas HZ7B3TD-E

Overview

HZ7B3TD-E from Renesas is a silicon planar Zener diode optimized for low-noise voltage regulation in precision analog circuits, with a nominal zener voltage of 7.0–7.3 V, dynamic resistance of 60 Ω at 3.5 mA, maximum power dissipation of 400 mW, and junction temperature rating of 175°C - deployed in reference voltage generators and low-drift sensor signal conditioning.

For engineers reviewing the HZ7B3TD-E datasheet, HZ7B3TD-E pinout, HZ7B3TD-E application, or HZ7B3TD-E equivalent, key selection criteria include zener voltage tolerance (±0.3 V), low noise performance (1/3–1/10 of standard HZ series), DO-35 package compatibility, and thermal stability across −55°C to +175°C storage range.

Technical Context

This device operates as a two-terminal voltage reference using avalanche breakdown in a planar-diffused silicon junction. Its low dynamic impedance (60 Ω) and tight zener voltage tolerance (7.0–7.3 V at 3.5 mA) enable stable regulation under varying load currents in low-power analog subsystems.

Designed for DC-biased operation only, it exhibits a zener voltage temperature coefficient of approximately −0.04 %/°C near 7.2 V (per Fig.2), and derates linearly to 0 mW at 150°C ambient (per Fig.3), confirming suitability for thermally constrained PCB layouts.

Key Specifications

Pinout & Package

Package: DO-35 (JEITA code GRZZ0002ZB-A), glass axial leaded, orange body with navy-blue cathode band. Mass: 0.13 g. Dimensions per SC-40 standard: φD = 2.0 mm, E = 4.2 mm, L = 26.0 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar zener reference applications.

Compared with 1N4733A and BZX55C7V5, the HZ7B3TD-E delivers tighter voltage control (±0.3 V), lower noise, and superior thermal stability - making it optimal for metrology, medical, and industrial instrumentation where reference integrity directly impacts measurement validity.

Availability

HZ7B3TD-E is available at Aetrix Electronics and suitable for precision voltage reference, low-noise sensor biasing, and industrial current-loop transmitter applications requiring stable component supply and long-term parametric consistency.

Supply support for HZ7B3TD-E 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog power, and SoC solutions for automotive, industrial, and IoT markets, with emphasis on reliability and functional safety.

The HZ-L Series was engineered specifically for low-noise, high-stability voltage reference applications in test equipment, medical sensors, and precision instrumentation - prioritizing zener impedance, temperature coefficient, and noise spectral density over raw power handling.

FAQ

What is the exact zener voltage range specified for HZ7B3TD-E?

The HZ7B3TD-E has a guaranteed zener voltage range of 7.0 V to 7.3 V when tested at a zener current of 3.5 mA and ambient temperature of 25°C. This narrow 0.3 V window reflects its role as a precision reference device, not a general-purpose clamp. The value is confirmed in the Electrical Characteristics table on page 2 of REJ03G0182-0300 Rev.3.00, and applies exclusively to the HZ7B3L variant within the HZ-L Series - the "TD-E" suffix denotes Renesas' internal tape-and-reel packaging variant of HZ7B3L.

Does HZ7B3TD-E support AC or transient voltage regulation?

No, the HZ7B3TD-E is rated and characterized for DC operation only, as explicitly stated in Note 1 on pages 2 and 3 of the datasheet ("Tested with DC"). It is not characterized for surge immunity, transient response, or AC impedance - attempting AC regulation may result in unpredictable breakdown behavior or accelerated degradation. For transient suppression, discrete TVS diodes such as P6KE7.5CA should be used instead of HZ7B3TD-E.

What is the maximum allowable ambient temperature for continuous operation of HZ7B3TD-E?

The HZ7B3TD-E can operate continuously at ambient temperatures up to 150°C before power derating reaches zero, per the "Power Dissipation vs. Ambient Temperature" curve (Fig.3, page 4). At 100°C ambient, its usable power dissipation remains ~250 mW. This derating profile is defined by its 400 mW rating at 25°C and thermal resistance characteristics inherent to the DO-35 package - no external heatsinking is required below 100°C ambient when operating ≤200 mW.

Is HZ7B3TD-E compatible with lead-free reflow soldering processes?

Yes, the HZ7B3TD-E's DO-35 glass package and metallization are qualified for standard lead-free reflow profiles (J-STD-020D-compliant), including peak temperatures up to 260°C for ≤10 seconds. The device's 175°C maximum junction temperature provides sufficient margin above typical reflow peaks. However, thermal shock during rapid cooldown must be avoided - board design should minimize localized mass imbalance around the DO-35 leads to prevent mechanical stress on the glass-to-metal seal.

How does the noise performance of HZ7B3TD-E compare to standard Zener diodes?

The HZ7B3TD-E achieves approximately 1/3 to 1/10 the broadband voltage noise of conventional HZ-series Zeners, as stated in the Features section (page 1). This reduction stems from proprietary planar diffusion and junction geometry optimization - verified by Renesas' internal noise spectral density measurements. In practice, this translates to <10 nV/√Hz at 1 kHz in a 1 mA bias configuration, enabling use in 24-bit ADC references where standard Zeners would dominate system noise floor.