1 Features
• Functional Safety-Capable
– Documentation available to aid functional safety
system design
• Configured for rugged industrial applications
– Input voltage range: 3.8 V to 36 V
– Output voltage range: 1 V to 24 V
– Peak-current mode control
– Junction temperature range: –40°C to +125°C
– Ease-of-use SOIC package
• Well-suited for scalable industrial power supplies
– Pin compatible with:
• LMR33610, LMR33620, and LMR33630 (36
V, 1 A, 2 A, or 3 A)
• LMR36510 and LMR36520
(65 V, 1 A, or 2 A)
– 400-kHz and 1-MHz frequency
– Integrated compensation helps reduce solution
size, cost, and design complexity
• High-efficiency solution
– Peak efficiency > 95%
– Low shutdown quiescent current of 5 μA
– Low operating quiescent current of 24 μA
• Flexible system interface
– Power-good flag and precision enable
• Create a custom design using the LMR33640 with
the WEBENCH® Power Designer
• Use TPSM53604 module for faster time to market

2 Applications
• Motor drive systems: drones, AC inverters,
VF drives, servos
• Factory and building automation systems:
PLC, HMI, HVAC systems, elevator main control
panel
• Wide VIN DC/DC power supply

3 Description
The LMR33640 SIMPLE SWITCHER® regulator is
an easy-to-use, synchronous, step-down DC/DC
converter that delivers best-in-class efficiency for
rugged industrial applications. The LMR33640 drives
up to 4 A of load current from an input of up
to 36 V. The LMR33640 provides high light-load
efficiency and output accuracy. Features such as a
power-good flag and precision enable provide both
flexible and easy-to-use solutions for a wide range
of applications. The LMR33640 automatically folds
back frequency at light load to improve efficiency.
Protection features include thermal shutdown, input
undervoltage lockout, cycle-by-cycle current limit, and
hiccup short-circuit protection. Integration and internal
compensation eliminates many external components
and provides a pinout designed for a simple PCB
layout. The feature set of the device is designed
to simplify implementation for a wide range of end
equipment. The LMR33640 is pin-to-pin compatible
with the LMR33610, LMR33620, LMR33630 (36 V, 1
A/2, A/3 A), LMR36510 (65 V, 1 A), and LMR36520
(65 V, 2 A), completing the family of scalable SIMPLE
SWITCHER power supplies. This minimizes the cost
and effort associated with board layout modifications.
The LMR33640 is available in an 8-pin HSOIC
package.