1 Features
• Designed for rugged industrial applications:
– Junction temperature range –40°C to +150°C
– Input transient protection up to 70 V
– Wide input voltage range: 3.0 V (falling
threshold) to 65 V
– Minimized switch node ringing to reduce EMI
– Adjustable and fixed output 3.3-V and 5-V
voltage options available
• Suited for scalable industrial power supplies:
– Pin compatible with LMR36503 (65 V, 300 mA)
and LMR36506 (65 V, 600 mA)
– Adjustable switching frequency: 200 kHz to
2.2 MHz with RT pin variant
• Minimized solution size and cost:
– Highest power density with internal
compensation and reduced external component
count
– Ultra-small, 2-mm × 2-mm HotRod™ package
• High efficiency across load range with low power
dissipation:
– Greater than 80% peak efficiency at 1 MHz
(3.3-V VOUT)

2 Applications
• Factory automation: field transmitters and process
sensors
• Building automation: HVAC and fire safety
notification and detectors
• Appliances: garden and power tools

3 Description
The LMR3650x is the industry smallest 65-V, 150-
mA (available in 100-mA variant) synchronous stepdown
DC/DC converter in 4-mm2 HotRod package.
This easy-to-use converter can handle input voltage
transients up to 70 V, provide excellent EMI
performance and supports fixed, 3.3 V, 5 V and other
adjustable output voltages.
The LMR3650x uses the peak current mode control
architecture with internal compensation to maintain
stable operation with minimal output capacitance. The
LMR3650x with the right resistor selection from the
RT pin to ground can be externally programmed to
any desired switching frequency of operation over a
wide range from 200 kHz to 2.2 MHz. The precision
EN/UVLO feature allows precise control of the device
during the start-up and shutdown. The PGOOD flag,
with built-in glitch filter and delayed release, offers
a true indication of the system status, eliminating
the requirement for an external voltage supervisor.
The compact solution size and rich feature set of
LMR3650x simplifies implementation for a wide range
of industrial applications