BZX585-B6V8 - 6.8V 300mW Zener Diode ±2% SOD-523 | Nexperia
MPN: BZX585-B6V8 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.26 | $0.26 |
| 10 | $0.21 | $2.10 |
| 100 | $0.16 | $16.00 |
| 500 | $0.12 | $60.00 |
| 1,000 | $0.09 | $90.00 |
| 3,000 | $0.07 | $210.00 |
BZX585-B6V8 Overview
A Zener diode is a specialized PN-junction diode engineered to operate in the reverse-breakdown (Zener) region, where the voltage across the device remains nearly constant over a wide range of reverse currents. This characteristic makes Zener diodes ideal as shunt voltage regulators, reference elements, and overvoltage protectors in analog and mixed-signal circuits. Within the broader semiconductor taxonomy, the BZX585-B6V8 sits at: Zener diode → voltage regulator diode → discrete semiconductor → diode → semiconductor device.
Key features of the BZX585-B6V8 include a maximum working voltage tolerance of ±2% (E24 normalized), a non-repetitive peak reverse power dissipation rating suitable for transient clamping, and a low-leakage planar construction that minimizes standby current in battery-powered designs. The device is supplied on 8 mm tape and reel for high-speed automated pick-and-place assembly.
The planar passivated die architecture yields stable Zener voltage across temperature and current, with a typical temperature coefficient consistent with the 5.6–6.8 V range where the Zener mechanism transitions from true Zener breakdown to avalanche multiplication. This range typically exhibits a near-zero temperature coefficient, making 6.8 V parts especially useful as low-drift references.
Typical applications include portable and wearable device voltage references, USB and HDMI port protection, ADC/DAC reference rails, microcontroller supervisor rails, RF transceiver local-oscillator supply filtering, and automotive infotainment analog signal conditioning. The 6.8 V nominal is also close to common logic-interface clamping levels for transient voltage suppressor (TVS) duty in conjunction with series resistors.
When designing with this part, observe the 300 mW total power dissipation limit and derate appropriately above 25 °C. A series resistor sized to limit Zener current to a few milliamps in regulation, plus a few milliamps of margin under worst-case input and load conditions, will keep the junction temperature within safe limits and ensure long-term stability.
This page consolidates distributor pricing, drop-in alternatives, and design notes not typically aggregated on a single manufacturer datasheet, with the goal of accelerating BOM validation and second-source selection for production designs.
Drop-in alternatives for BZX585-B6V8 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
BZX585-B6V8-QX
✅ Drop-In📋 Reference alternative (not in catalog)
BZX585-C6V8
✅ Drop-In📋 Reference alternative (not in catalog)
BZX585-B6V8,135
✅ Drop-In📋 Reference alternative (not in catalog)
BZX585-B6V8,115
✅ Drop-In📋 Reference alternative (not in catalog)
BZX585-B6V2-QX
✅ Drop-In📋 Reference alternative (not in catalog)
BZX585-B6V8 Maximum Ratings & Electrical Characteristics
| Zener Nominal Voltage (Vz) | 6.8 V |
| Zener Voltage Tolerance | ±2% (BZX585-B series) |
| Total Power Dissipation (Ptot) | 300 mW |
| Working Voltage Range (Nominal) | 2.4 V to 75 V (series) |
| Package | SOD-523 (ultra-small SMD) |
| Mounting Type | Surface Mount |
| Tolerance Series Available | ±2% (B), ±5% (C) |
| Number of Terminals | 2 |
| Diode Configuration | Single (voltage regulator) |
| RoHS Status | Compliant |
| Tape and Reel Packaging | 8 mm tape, 3000 pcs/reel (typical) |
| Marking Code | E2 |
| Automotive Qualified Variant | BZX585-B6V8-QX (AEC-Q101) |
BZX585-B6V8 Pin Configuration
| Pin 1 | Cathode (K) — Cathode terminal - marked with colored bar on SOD-523 top surface |
| Pin 2 | Anode (A) — Anode terminal - unmarked on SOD-523 top surface |
Typical Applications
BZX585-B6V8 is suitable for 6 applications: Portable Device Voltage Reference, USB / HDMI Port Voltage Clamp, ADC / DAC Reference Rail, Microcontroller Supervisor Rail, RF Transceiver Local Oscillator Filtering, Automotive Infotainment Analog Signal Conditioning.
Portable Device Voltage Reference
The BZX585-B6V8 provides a compact 6.8 V reference rail for battery-powered portable and wearable electronics, where its SOD-523 footprint (1.6 mm x 0.8 mm) and 300 mW rating fit easily alongside a microcontroller, BLE SoC, or sensor. Operating at 5 mA typical test current, the diode dissipates roughly 34 mW, leaving ample margin for transient clamping while preserving battery life. The ±2% tolerance supports ADC reference inputs on low-power analog front-ends, and the near-zero temperature coefficient at 6.8 V minimizes drift across the -20 °C to +60 °C portable operating range. Compared to a bandgap reference IC, the BZX585-B6V8 is lower cost and smaller but trades off initial accuracy and noise.
Recommended
USB / HDMI Port Voltage Clamp
The BZX585-B6V8 is well suited as a low-power clamping element on USB 2.0 and HDMI interface lines when paired with a series resistor. Its 6.8 V nominal Zener voltage sits just above the 5 V signal rail, providing secondary overvoltage protection against ESD-induced ringing or accidental short to a higher-voltage rail. The SOD-523 package allows placement directly at the connector body, minimizing parasitic inductance. For high-surge applications (>1 kV ESD), supplement with a dedicated TVS array such as the PESD5V0L4UG; the BZX585-B6V8 alone is not rated for repeated IEC 61000-4-2 strikes.
Recommended
ADC / DAC Reference Rail
The BZX585-B6V8 serves as a low-cost 6.8 V reference for low-resolution ADCs and DACs in industrial and consumer designs where a dedicated bandgap reference IC is over-specified. At the 6.8 V Zener knee, the temperature coefficient is near zero, giving stable readings across operating temperatures without the cost of a precision reference like the ADR01 or LM4040. The 300 mW rating supports continuous operation at 5-10 mA with adequate series-resistor headroom. Designers should bypass the Zener with a 100 nF ceramic capacitor to filter high-frequency noise that could otherwise couple into the converter's reference pin and degrade SNR.
Recommended
Microcontroller Supervisor Rail
The BZX585-B6V8 provides a stable 6.8 V rail for microcontroller supervisor circuits, voltage monitoring ICs, and reset generators in industrial control systems. When combined with a low-dropout regulator and a comparator-based reset supervisor, the Zener establishes a well-defined upper threshold for brown-out detection. The ±2% tolerance (±136 mV at 6.8 V) keeps the reset threshold consistent across production units, reducing field failures due to marginal voltage excursions. The automotive-grade BZX585-B6V8-QX is recommended for vehicle ECU designs where AEC-Q101 qualification is mandatory.
Recommended
RF Transceiver Local Oscillator Filtering
The BZX585-B6V8 functions as a clean supply-rail bypass element in RF transceiver designs, where its low-noise Zener characteristic and small SOD-523 package allow placement close to VCO/PLL supply pins. At 6.8 V, the breakdown mechanism is in the avalanche regime, exhibiting a flat noise spectrum suitable for low-phase-noise local oscillator circuits. Combined with ferrite beads and decoupling capacitors, it forms a compact Pi-filter network that suppresses broadband supply noise. Designers should verify that the diode's 5 mA operating current is compatible with the LDO's quiescent current budget, as the Zener continuously draws current even when the RF section is idle.
Recommended
Automotive Infotainment Analog Signal Conditioning
The BZX585-B6V8-QX (AEC-Q101 automotive grade) provides a 6.8 V reference rail for analog signal conditioning in automotive infotainment head units, instrument clusters, and telematic modules. The automotive-qualified die ensures operation across the -40 °C to +150 °C automotive temperature range with proven reliability under thermal cycling and vibration. The SOD-523 footprint supports dense PCB layouts typical of modern head-unit designs, and the ±2% tolerance is adequate for audio crossover networks and sensor-signal scaling where reference accuracy is not the dominant error source. For safety-critical ADAS applications, use a dedicated ASIL-rated reference rather than a Zener.
Recommended
Recommended Products Summary
Engineering reference data for BZX585-B6V8 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BZX585-B6V8-QX | BZX585-C6V8 | BZX585-B6V8,135 | BZX585-B6V8,115 | BZX585-B6V2-QX |
|---|---|---|---|---|---|---|
| Brand | Nexperia | Nexperia | Nexperia | Nexperia | Nexperia | Nexperia |
| Package | SOD-523 | SOD-523 - same | SOD-523 - same | SOD-523 - same | SOD-523 - same | SOD-523 - same |
| Zener Nominal Voltage | 6.8 V | 6.8 V | 6.8 V | 6.8 V | 6.8 V | 6.2 V |
| Tolerance | ±2% (B) | ±2% (B) | ±5% (C) | ±2% (B) | ±2% (B) | ±2% (B) |
| Power Dissipation | 300 mW | 300 mW | 300 mW | 300 mW | 300 mW | 300 mW |
| AEC-Q101 Automotive Grade | No (standard) | Yes | No | No | No | Yes |
| Reel Code | Standard (115/135 variants) | QX suffix | 115/135 standard | 135 | 115 | QX suffix |
Key Differentiators
- Tightest tolerance in BZX585 6.8V family (vs BZX585-C6V8)
- Automotive-qualified variant available in same footprint (vs BZX585-B6V8 standard)
- Single-junction ultra-small SOD-523 footprint (vs BZX84C6V8 (SOT-23))
Design Notes
Estimated: at 5 mA nominal Zener current and 6.8 V nominal voltage, the BZX585-B6V8 dissipates approximately 34 mW steady-state. The SOD-523 thermal resistance is in the 300-450 C/W range per typical Nexperia packaging data, yielding a junction temperature rise of 10-15 °C above ambient - well within the 300 mW rating. Designers planning for continuous maximum-current operation (20-30 mA) should derate power linearly above 25 °C and verify theta_JA on the actual PCB layout; an insufficient copper pour can push the junction well past 150 °C under fault conditions.
SOD-523 land pads must be 0.6 mm x 0.5 mm minimum with 1.4 mm pitch; do not use the SOT-23 land pattern by mistake (1.9 mm x 1.3 mm pads, 2.9 mm pitch). Place the diode close to the protected node (connector, reference pin) to minimize parasitic inductance. For series-resistor/Zener clamp networks, the series resistor should be sized for the maximum expected fault current; a typical value is 10-100 Ω for low-current signal lines, and the Zener must be within 5 mm of the protected pin to remain effective against fast ESD transients.
Do not assume BZX585-B6V8 is a TVS - it is a continuous-duty voltage regulator diode and will fail if subjected to repeated high-energy transients. Do not operate it near its absolute maximum current for prolonged periods - the 300 mW power rating assumes 25 °C and derates above. Verify the cathode orientation against the datasheet marking diagram; reversed bias in normal forward conduction is allowed but defeats the regulator function. Finally, the BZX585-B6V8-Zener knee voltage has a positive temperature coefficient above ~5.6 V, so the rail will shift a few mV per °C - acceptable for clamping but inadequate for precision reference applications.
Compliance Information
RoHS and REACH compliant per Nexperia product page. AEC-Q101 qualified variant available as BZX585-B6V8-QX (note: AEC-Q100 query maps to AEC-Q101 for discrete diodes). Halogen-free status not explicitly stated in verified web data.
