An ideal diode = NMOS + dedicated controller

一．Advantages：

1. Extremely low power consumption：The conduction voltage drop is only 10-20 mV, and the power consumption drops to 0.4W at a current of 20A (97% lower than that of Schottky diodes), without the need for an additional heat sink.；

2. Instantaneous Response: The reverse current detection response time is less than 1 μs, completely eliminating reverse recovery surges and avoiding impact on the downstream chips; 

3. Wide-range compatibility: Some models can withstand reverse voltages up to -65V, covering extreme scenarios such as reverse connection of 12V automotive batteries (-12V) and fluctuations of 24V industrial power supplies.

二．The mainstream dedicated controller models and suitable scenarios for current ideal diodes: 

TI LM74700: With a 65V withstand voltage and integrated over-temperature protection, it is suitable for redundant design of automotive electronic power supplies. 

LM5050-1: With a 75V withstand voltage and low static current (7μA), it is suitable for portable devices powered by batteries. 

2. Rongpai Pai8150x/Pai8151x Series: Supports back-to-back FET architecture, battery reverse protection, and power path redundancy, suitable for the low-voltage system of new energy vehicles. 

3. Meixin MX16171: With a wide input voltage range of 1-50V, it supports parallel current expansion and is the preferred choice for industrial control redundant power supplies. 

Xinzhou Technology SCT53600Q: With ±65V withstand voltage, AEC-Q101 certification, it is a core protection component for vehicle ECU and BMS systems.

三、Traditional diode PK Ideal diode, as shown in the table below:

四．Leiditech TVS + Ideal Diodes, 12V/24V DC Power Surge Protection Solution：

"Double Barrier" Protection Logic: The synergy between the ideal diode and TVS must satisfy the "time + energy" two-dimensional coordination: 

Ideal Diode: Responsible for reverse current blocking (for example, the Pai8151 series from Rongpai can be turned off within 0.75 μS) and continuous overcurrent protection (such as the SCT53600Q from Xingzhou supports a 50A overload for 10ms); 

Lei Ma TVS: It is capable of dissipating positive surge energy (response time < 1ns) and voltage clamping (the Lei Ma TVS diode limits the transient voltage within the ideal diode's withstand voltage range).

1. 12V automotive electronic solution (meeting ISO 7637-2 test requirements)

· Core components: 

Ideal diode-specific controller: Rongpai Pai8150C (-55V to 80V voltage rating, AEC-Q100 certified); 

o TVS: Lebao SM8S24CA (24V VRWM, 38.9V VC, 6600W peak power, AEC-Q101 certification).

· Parameter matching logic：

o VRWM = 24V (1.2 × 12V system voltage), ensuring that the TVS has no leakage current during normal operation; 

o VC = 38.9V (< 80V withstand voltage of Pai8150C), preventing surge-induced breakdown of the MOSFET; 

The peak current IPP is 170A (greater than the 100A requirement specified in ISO 7637-2 for a 5A pulse). 

· Actual performance: The EMC team conducted verification in the Lebao laboratory environment: 

Pulse 5A test (100V input, 1Ω source impedance, 300ms): The clamp voltage remained stable at 38.5V; 

Reverse connection test (-12V for 1 minute): The Pai8150C quickly shuts off, and the back-end circuit is undamaged. 

2. 24V Industrial Control Surge Protection Solution (meets IEC 61000-4-5 Class 3 standard)

· Core component：

oIdeal Diode: Rongpai Pai8150C (-55V to 80V Voltage Rating) 

o TVS: Lebao SMDJ26CA (26V VRWM, 42V VC, 3000W peak power).

· Parameter matching logic：

o VRWM = 26V (1.08 times the 24V system voltage), suitable for industrial power supply fluctuations; 

O VC = 42V (< 80V withstand voltage of Pai8150C), for protecting the driving circuit; 

The redundant design can be combined with the Lebao GDT (2R090-5S) to form a two-level protection system. The GDT can handle 80% of the surge current (greater than 2kA). 

· Actual performance: 2kV surge test (8/20μs waveform): System voltage drop ≤ 5V, no reset of the rear-end PLC;

3.Charging Control and Surge Protection Scheme for 12V Auxiliary Battery of Electric Vehicles：

The 12V auxiliary battery for electric vehicles needs to address 3 issues: 

During charging, it can be controlled to switch on and off (the charging will automatically stop when fully charged to avoid reverse discharge); 

Two-way power supply during startup (12V battery charges the capacitor on the high-voltage side beforehand); 

Protect against two types of surges:

ü Voltage surges (such as lightning strikes, power spikes, which can damage circuits)；

Shanghai Lebao Scheme Architecture：

Pre-stage TVS: Clamping transient overvoltage. The lightning arrester uses SM8S24CA and meets the ISO 7637-2 test requirements. 

Back-to-back MOSFETs (Q1 + Q2): Work in conjunction with the controller to achieve charging path switching + bidirectional conduction;

ü Charging path enabled: EN signal low → Q1 and Q2 conduct → DC/DC charges the battery；

ü Charging path failure: Battery fully charged → EN signal high → Q1 and Q2 turn off → Cut off circuit to prevent reverse discharge。

ü When the controller cathode (CATHODE) pin is left floating → it allows the energy to flow in the reverse direction (for example, a 12V battery charges the capacitor on the high-voltage side beforehand)。

Ideal Diode Controller: Drives MOSFETs, with built-in soft-start logic (using an external RC network to delay the start-up).

Lei Mou has achieved this by scientifically combining TVS and ideal diodes. Not only does this solve the power consumption and reliability issues of traditional diodes, but it also enables the establishment of a surge protection system that complies with international standards.。

Leiditech Electronics is committed to becoming a leading brand in electromagnetic compatibility solutions and component supply, offering products such as ESD, TVS, TSS, GDT, MOV, MOSFET, Zener, inductors, etc. Leiditech has its own free laboratory and has an experienced R&D team, which can provide personalized customization services according to customer needs and offer the best solutions for customers.