1 Features

• AEC-Q100 qualified for automotive applications

– Temperature grade 1: –40°C to +125°C, TA

• Functional Safety-Compliant

– Developed for functional safety applications

– Documentation to aid ISO26262 system design

up to ASIL C

• Highly integrated squib driver solution targeted at

automotive EV pyro-fuse application

– Integration of power supplies, current

regulation, diagnostics, and safety functions

– SPI or HW pin-based triggering for flexible

interface options and rapid firing reaction

– Diagnostic functions for system energy

reservoir capacitor and squib health monitoring

– Built-in-self-test and diagnostic functions for

power supplies, interfaces, drivers, and

monitors

– Architecture for reliable operation with

redundant power supplies, low-side and highdriver

drivers, and secondary monitoring logic

• Up to 28-V (40-V abs. max) operating voltage

• Compact HVSSOP-28 (DGQ) leaded package

• Two-wire load interface with protected, current

controlled high-side and protected secondary lowside

switches

• Integrated charge pump for minimal MOSFET drop

out voltage

• 4-wire, addressable, 24-bit SPI with CRC

protection

– Allows multiple device to operate on the same

SPI

– Allows for broadcast commands to multiple

devices.

• Configurable deployment currents (1.2 A / 2 ms,

1.75 A / 0.5 ms, up to 3.4 A / 0.5 ms)

• Configurable deployment interface options

– 2-pin HW trigger with PWM or level signaling

– Protected SPI command with CRC

• Comprehensive off-state diagnostics

– Device built-in-self-test

– Driver output and switch test

– Interface test

– Energy reservoir capacitor test

– Squib resistance test

• Configurable fault indicator (nFAULT)

2 Applications

• Squib driver

• Automotive EV pyro-fuse

• Battery disconnect unit

• Battery junction box

3 Description

The DRV3901-Q1 is a highly integrated squib driver intended for automotive EV pyro-fuse applications. It

includes the power supplies, current sensing and regulation, and diagnostics and protection functions needed to

drive a squib load. It incorporates several key functions unique to the device that are different from traditional

squib drivers. These functions include a hardware pin trigger interface, an energy reservoir capacitor diagnostic,

an addressable SPI, and optimized driver stage with integrated charge pump and additional deployment current

options.

The hardware pin trigger (TRGx) interface allows for a deployment command to be issued directly in hardware to

the DRV3901-Q1. This allows the flexiblity to either trigger the deployment with MCU hardware pins, directly with

an overcurrent sensor, or through other external hardware circuit monitors. The hardware trigger pins support

a 2-pin interface with both threshold or PWM based options to ensure robustness against miss deployment

while still providing flexiblity to support a variety of interface options. Additionally, CRC protected deployment

commands can be sent through the SPI bus as a secondary method.

To support a diagnostic for the system energy reservoir capacitor, the DRV3901-Q1 integrates a switch and

monitor circuit to be able to bias and monitor the discharge voltage of the reservoir capacitor. This enables the

device and the external MCU to detect a loss/failure of the reservoir capacitor or its approximate value in normal

operation.

An addressable SPI, allow multiple devices to be controlled on a shared SPI bus. In addition to reducing required

MCU resources, the addressable SPI incorporates a broadcast command structure that allows multiple drivers

to be coordinated to trigger simultaneously or with staggered delays. The SPI incorporate multiple robustness

functions including a CRC, address readback capability, and various bus fault detection mechanisms.

The power stage utilizes a protected high-side and low-side switch to ensure robustness against unintended

driving due to a variety of fault conditions. An integrated charge pump ensures minimal drop out voltage across

the switches during deployment to enable operation down to low supply voltages. A wide variety of deployment

options are available to optimize for different types of squib loads or for specific application requirements.