1 Features

• LM3478Q-Q1 is AEC-Q100 qualified and

manufactured on an automotive grade flow

• 8-lead VSSOP-8

• Internal push-pull driver with 1A peak current

capability

• Current limit and thermal shutdown

• Frequency compensation optimized with a

capacitor and a resistor

• Internal soft start

• Current mode operation

• Undervoltage lockout with hysteresis

• Key specifications:

– Wide supply voltage range of 2.97V to 40V

– 100kHz to 1MHz adjustable clock frequency

– ±2.5% (overtemperature) internal reference

– 10μA shutdown current (overtemperature)

• Create a custom design using the LM3478Q-Q1

with the WEBENCH Power Designer

2 Applications

• Isolated supply (flyback) in traction inverters and

On-board chargers

• ADAS - Driver monitoring

• Digital cockpit and head unit

3 Description

The LM3478Q-Q1 is a versatile Low-Side N-Channel

MOSFET controller for switching regulators. It is

suitable for use in topologies requiring a low side

MOSFET, such as boost, flyback, SEPIC, etc.

Moreover, the LM3478Q-Q1 can be operated at

extremely high switching frequency in order to reduce

the overall solution size. The switching frequency

of the LM3478Q-Q1 can be adjusted to any value

between 100kHz and 1MHz by using a single

external resistor. Current mode control provides

superior bandwidth and transient response, besides

cycle-by-cycle current limiting. Output current can be

programmed with a single external resistor.

The LM3478Q-Q1 has built in features such as

thermal shutdown, short-circuit protection, over

voltage protection, etc. Power saving shutdown mode

reduces the total supply current to 5μA and allows

power supply sequencing. Internal soft-start limits the

inrush current at start-up.