Diodes AP74701Q Ideal Diode Controller Eliminates External TVS in Automotive RVP

Diodes’ AP74701Q Simplifies Automotive Reverse-Voltage Protection

Reverse-voltage events can cause serious damage to automotive electronics, particularly in systems connected directly to the vehicle battery. Engineers often counter this with ideal diode controllers and transient voltage suppression (TVS) diodes, but this approach adds cost, consumes space, and increases component count. Diodes Incorporated’s new AP74701Q takes a different path, integrating a VDS clamp that removes the need for an external TVS while still meeting ISO 7637 transient immunity requirements.

Built for Harsh Automotive Power Environments

Designed for both 12 V and 24 V battery systems, the AP74701Q operates across a 3.2 V to 65 V input range and withstands reverse voltages down to –33 V. This wide margin covers demanding conditions such as cold cranking, load dumps, and other transients common in automotive electrical systems.

The device actively drives an external N-channel MOSFET, maintaining a forward voltage drop of just 20 mV. This low drop minimises conduction losses and heat build-up, which can be critical in compact, thermally constrained automotive modules.

Fast Protection When It Counts

When reverse current is detected, the AP74701Q responds in under 0.75 µs, providing immediate isolation of downstream circuits. Its optimised regulation scheme ensures output voltage hold-up during transient events, helping to maintain stable operation for sensitive loads like infotainment units, advanced driver-assistance systems (ADAS), and LED lighting modules.

The part also draws just 1 µA in shutdown mode, which is beneficial in vehicles where every microamp of standby current matters for battery longevity.

Automotive-Grade Reliability

Qualified to AEC-Q100 Grade 1, the AP74701Q supports operation from –40 °C to +125 °C ambient, with a junction temperature rating up to 150 °C. It is produced in IATF 16949-certified facilities and is available in a compact SOT-28 package, making it suitable for high-volume automotive manufacturing and PPAP documentation requirements.

Where It Fits

The AP74701Q’s combination of high-speed protection, integrated VDS clamp, and low-loss operation makes it a strong fit for:

• Infotainment systems
• ADAS modules
• Exterior and interior lighting
• USB charging ports
• Active OR-ing in redundant supply architectures

By removing the need for an external TVS, the device not only simplifies reverse-voltage protection design but also reduces bill-of-materials costs and PCB space, an advantage in the increasingly dense electronics found in modern vehicles.

Learn more and read the original announcement here.