Family of 16-bit CAN-enabled CompactRISC Microcontrollers# Technical Documentation: CR16MAS9VJE8 - 16V, 9A Schottky Barrier Rectifier
Manufacturer : NSC (National Semiconductor)
Component Type : Schottky Barrier Rectifier
Document Revision : 1.0
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## 1. Application Scenarios
### 1.1 Typical Use Cases
The CR16MAS9VJE8 is a high-current, low-forward-voltage Schottky rectifier designed for applications requiring efficient power conversion and minimal voltage loss. Its primary use cases include:
* Switch-Mode Power Supply (SMPS) Output Rectification : Employed in the secondary side of flyback, forward, and buck-derived converters, particularly in low-voltage, high-current outputs (e.g., 5V, 3.3V, 1.8V rails). Its low VF directly reduces power loss and improves overall power supply efficiency.
* Freewheeling/Clamping Diode in DC-DC Converters : Used in synchronous and non-synchronous buck, boost, and buck-boost converter topologies to provide a path for inductor current during switch-off periods, preventing voltage spikes and protecting the main switching element (MOSFET).
* Reverse Polarity Protection : Placed in series with the power input rail, it blocks reverse voltage while introducing minimal forward voltage drop, protecting downstream circuitry.
* OR-ing Diode in Redundant Power Supplies : Used in systems with multiple power inputs (e.g., server blades, telecom systems) to isolate supplies and allow current flow only from the higher-voltage source, preventing back-feeding.
### 1.2 Industry Applications
* Computing & Servers : Point-of-Load (PoL) converters on motherboards and GPU cards, VRM (Voltage Regulator Module) circuits, and SSD power circuits.
* Telecommunications & Networking : Rectification in DC-DC converter modules for board-level power distribution, power-over-Ethernet (PoE) circuits, and base station power systems.
* Consumer Electronics : Power sections of LCD/LED TVs, gaming consoles, set-top boxes, and high-power adapters/chargers.
* Industrial Electronics : Motor drive circuits, programmable logic controller (PLC) I/O power isolation, and general-purpose industrial SMPS.
### 1.3 Practical Advantages and Limitations
Advantages:
* High Efficiency: Very low forward voltage drop (typically ~0.55V at 9A) minimizes conduction losses, leading to cooler operation and higher system efficiency, especially critical in high-current applications.
* Fast Switching: Schottky technology provides extremely fast reverse recovery time (effectively negligible compared to PN-junction diodes), reducing switching losses in high-frequency circuits (>100 kHz) and minimizing voltage ringing.
* Low Thermal Load: The combination of low VF and fast switching reduces power dissipation, simplifying thermal management.
Limitations:
* Higher Reverse Leakage Current: Schottky diodes exhibit significantly higher reverse leakage current (IR) than standard silicon diodes, which increases with temperature. This can be a critical factor in high-temperature environments or applications sensitive to standby power consumption.
* Limited Reverse Voltage Rating: The maximum repetitive reverse voltage (VRRM) of 16V restricts its use to low-voltage circuits. It is unsuitable for offline or high-voltage DC bus applications.
* Thermal Derating: While efficient, at full rated current (9A), the device will still dissipate several watts of heat. Adequate heatsinking or PCB copper area is mandatory for reliable operation.
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## 2. Design Considerations
### 2.1 Common Design Pitfalls and Solutions
* Pitfall 1: Thermal Run
