1 Features
• Functional Safety-Capable
– Documentation available to aid IEC 61508-2
system design
• Versatile synchronous buck converter family
– Wide input voltage range of 3.5V to 65V
– 4A, 6A, and 8A output current options
– Adjustable output voltage from 0.8V to 60V, or
fixed output options of 3.3V and 5V
– 150°C maximum junction temperature
– 36ns tON(min) for high step-down conversion
• ZEN 1 switcher technology
– Facilitates CISPR 11 or 32 Class B compliance
– Enhanced HotRod™ QFN (eQFN) package with
symmetrical pinout design and minimal LLOOP
– Spread Spectrum (DRSS) and switching slewrate
control reduce peak emissions
– Switching frequency from 300kHz to 2.2MHz
– AUTO, FPWM, or SYNC operation
• High efficiency across the full load current range
– 95% at 48VIN, 12VOUT, 8A, 400kHz
– Multiphase stackable for higher output current
– Dual-input VCC subregulator with BIAS option
– VIN sleep quiescent current as low as 1.8μA
• Improved reliability with optimized pinout design
and clearance for short-circuit-to-adjacent-pin test
– VIN to PGND pin clearance of 1.1mm
• Create a custom design using the LM65680/60/40
converter with WEBENCH® Power Designer

2 Applications
• Industrial automation, test and measurement
• Medical imaging systems, energy infrastructure
• Enterprise systems, wireless infrastructure

3 Description
The LM65680/60/40 is a synchronous buck DC/DC
converter offered from a family of devices with ZEN 1
technology designed for low EMI, high power density,
and excellent conversion efficiency. Integrated power
MOSFETs with low RDS(on) enable up to 8A of output
current across a wide input voltage range of 3.5V to
65V.
Phase stackable with synchronized interleaving,
the peak current-mode control architecture of the
LM65680/60/40 supports accurate current sharing
with paralleled phases for higher output currents.
AUTO mode enables frequency foldback during lightload
operation, giving high light-load efficiency and a
no-load input current as low as 2.2μA, which extends
operating run-time in battery-powered systems.
A high-side switch minimum on-time of 36ns facilitates
large step-down ratios, enabling the direct conversion
from 24V or 48V inputs to low-voltage rails for
reduced system cost and complexity. The package
has several NC pins between critical power pins,
which improve the Failure Modes and Effects Analysis
(FMEA) result.