1 Features

• AEC-Q100 qualified for automotive applications

– Device temperature grade 1: –40°C to 125°C

ambient operating temperature range

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• Wide operating input voltage: 3V to 36V (42V

absolute maximum)

• Ultra-low quiescent current

– Shutdown current: 0.65μA

– No load standby current: 5μA

• Pin programmable output voltage options available

in fixed 3.3V/ADJ and 5V/ADJ

– Adjustable output voltage range from 1V to 20V

• Low minimum tON (30ns typical)

• Designed for low electromagnetic interference

(EMI) requirements:

– Facilitates CISPR 25 class 5 compliance

– Low inductance HotRod™ QFN package

– Spread spectrum options available

• Programmable switching frequency from

200kHz – 2.2MHz

• FPWM, PFM, or external frequency

synchronization available

• Designed for scalable power supplies

– Pin compatible with LMR60406-Q1,

LMR60410-Q1, LMR60430-Q1, and

LMR60440-Q1

• Power-Good output for power sequencing

2 Applications

• Automotive camera applications

• Automotive driver assistance systems

• Automotive body applications

3 Description

The LMR60420-Q1 is a 3V to 36V (42V transient), 2A,

synchronous buck converter designed for automotive

applications. The LMR60420-Q1 offers variants with

spread spectrum in an ultra-compact, 2.5mm ×

2mm, HotRod QFN-9 package with wettable flanks

available, which reduces inductance and achieves

low (EMI) performance to facilitate qualification of

automotive and other noise-sensitive designs. All

device variants are capable of output voltages ranging

from 1V to 20V by including a resistor divider

between the output voltage node, feedback, and

ground. Each variant of the device is also capable

of delivering a fixed output voltage by connecting

the output voltage node directly to the feedback pin.

The Device Comparison Table provides details on

the fixed output voltage options. The current-mode

control architecture with 30ns minimum on-time allows

high conversion ratios at high frequencies, easy loop

compensation, fast transient response, and excellent

load and line regulation. An open drain power-good

output facilitates power sequencing requirements.

The MODE/SYNC pin of the LMR60420-Q1 allows

the user to select between modes of operation.

Forced pulse width modulation (FPWM) mode results

in constant switching frequency across load while

auto mode allows for seamless transitions between

pulse width modulation (PWM) and pulse frequency

modulation (PFM) switching. In auto mode, the

LMR60420-Q1 consumes only 5μA of quiescent

current, which makes sure of high efficiency at all

loads. Few external components are needed allowing

for compact PCB layout. The LMR60420-Q1 is a

part of a family of pin compatible devices ranging in

current levels from 0.6A to 6A.