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Manufacturer: ROHM

Part Number: RLZ-TE-11-5.6B

Specifications:

• Type: Zener Diode
• Zener Voltage (Vz): 5.6V
• Power Dissipation (Pd): 500mW
• Forward Voltage (Vf): 1.2V (typical)
• Reverse Leakage Current (Ir): 5μA (max at 1V)
• Operating Temperature Range: -55°C to +150°C
• Package: SOD-523 (Miniature Surface Mount)

Descriptions:

The RLZ-TE-11-5.6B is a surface-mount Zener diode from ROHM, designed for voltage regulation and protection in compact electronic circuits. It features a precise 5.6V breakdown voltage and low leakage current, making it suitable for applications requiring stable voltage references.

Features:

• High Reliability: Stable performance under varying conditions.
• Low Leakage Current: Ensures minimal power loss.
• Compact Package: SOD-523 (1.2mm x 0.8mm) for space-constrained designs.
• Wide Temperature Range: Operates effectively in harsh environments.

This diode is commonly used in voltage clamping, regulation, and ESD protection circuits in consumer electronics, automotive, and industrial applications.

# RLZ-TE-11-5.6B: Technical Analysis and Implementation Guide

## Practical Application Scenarios

The RLZ-TE-11-5.6B is a Zener diode from ROHM, designed for voltage regulation and transient suppression in low-power circuits. Its 5.6V breakdown voltage and compact SOD-323F package make it suitable for several key applications:

1. Voltage Regulation in Portable Electronics

The diode is commonly used to stabilize voltage rails in battery-powered devices, such as wearables and IoT sensors, where precise 5.6V references are required for analog or digital subsystems. Its low leakage current (<1µA) ensures minimal power drain.

2. ESD and Surge Protection

In communication interfaces (e.g., USB, UART), the RLZ-TE-11-5.6B clamps transient voltages, protecting downstream ICs from electrostatic discharge (ESD) and inductive load spikes. Its fast response time (<1ns) is critical for high-speed data lines.

3. Voltage Clamping in Automotive Systems

The component meets AEC-Q101 qualifications, making it viable for automotive applications like infotainment or CAN bus systems, where it safeguards 5V logic circuits from load-dump transients.

## Common Design-Phase Pitfalls and Avoidance Strategies

1. Thermal Runaway in High-Current Conditions

Pitfall: Exceeding the diode’s 200mW power dissipation limit can cause thermal runaway, leading to failure.

Solution: Calculate worst-case power dissipation (P = Vz × Iz) and derate values at elevated temperatures. Use a heatsink or select a higher-power variant if needed.

2. Inadequate Voltage Margin for Clamping

Pitfall: Designing with a 5.6V Zener for a 5V rail may result in insufficient headroom during tolerance stacking.

Solution: Verify the Zener’s tolerance (±5%) and ensure the clamped voltage (Vz + Zzt × Iz) remains below the target IC’s absolute maximum rating.

3. Poor PCB Layout Practices

Pitfall: Long trace lengths between the Zener and protected IC increase parasitic inductance, reducing clamping effectiveness.

Solution: Place the diode as close as possible to the protected node, using short, wide traces to minimize impedance.

## Key Technical Considerations for Implementation

1. Dynamic Impedance (Zzt)

The RLZ-TE-11-5.6B’s Zzt (~20Ω at 5mA) affects regulation accuracy. For precision applications, bias the diode near its test current (5mA) to minimize impedance variations.

2. Temperature Coefficient

The diode exhibits a nominal temperature coefficient of +2mV/°C. In wide-temperature environments (e.g., automotive), compensate for voltage drift using temperature-stable references.

3. Reverse Leakage Current

Below the breakdown voltage, leakage currents (<1µA) are negligible but must be accounted for in ultra-low-power designs to avoid unintended battery drain.

By addressing these factors, designers can leverage the RLZ-TE-11-5.6B effectively while mitigating risks in voltage-sensitive applications.