2.97~40V Wide Input Range Boost/SEPIC/Flyback DC-DC Controller


Product details


Vin (Min) (V) 2.97 Vin (Max) (V) 40 Vout (Min) (V) 1.26 Vout (Max) (V) 500 Regulated outputs (#) 1 Switching frequency (Min) (kHz) 100 Switching frequency (Max) (kHz) 1000 Iq (Typ) (mA) 2.7 Features Adjustable Current Limit, Enable, Frequency Synchronization, Light Load Efficiency, Pre-Bias Start-Up Duty cycle (Max) (%) 100 Rating Catalog Operating temperature range (C) -40 to 125 open-in-new Find other Boost controllers (external switch)

Package | Pins | Size

SOIC (D) 8 19 mm² 4.9 x 3.9 VSSOP (DGK) 8 15 mm² 3 x 4.9 open-in-new Find other Boost controllers (external switch)


  • 8-lead VSSOP-8 and SOIC-8 packages
  • Internal Push-Pull Driver With 1-A 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
  • Create a Custom Design Using the LM3478 with the WEBENCH Power Designer
open-in-new Find other Boost controllers (external switch)


The LM3478 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 LM3478 can be operated at extremely high switching frequency in order to reduce the overall solution size. The switching frequency of the LM3478 can be adjusted to any value between 100 kHz and 1 MHz 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 LM3478 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 5 µA and allows power supply sequencing. Internal soft-start limits the inrush current at start-up.

open-in-new Find other Boost controllers (external switch)
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Technical documentation

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide

High Efficiency Low-Side N-Channel Controller for Switching Regulator

  • 8-lead Mini-SO8 (MSOP-8) package
  • Internal push-pull driver with 1A peak current capability
  • Curent limit and thermal shutdown
  • Frequency compensation optimized with a capacitor and a resistor
  • Internal soft start
  • Current mode operation
  • Undervoltage lockout with hysteresis


Design tools & simulation

SNVMAW8C.ZIP (124 KB) - PSpice Model
SNVMAW9B.ZIP (5 KB) - PSpice Model
SNVMB83A.TSC (98 KB) - TINA-TI Reference Design
SNVMB84A.ZIP (9 KB) - TINA-TI Spice Model
SNVMBH8.ZIP (170 KB) - PSpice Model
SNVMBL8.ZIP (2 KB) - PSpice Model
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
Fly-Buck and Flyback Topology Selector
FLYBUCK-FLYBACK-DESIGN-CALC This tool helps a power supply engineer to select the right isolated DC-DC topology based on the specifications. Depending on the topology chosen, the calculator also recommends the right IC for the design.
  • Features isolated topologies like Fly-Buck™, Fly-Buck-Boost, DCM and CCM Flyback
  • Capability to design up to 6 isolated outputs
  • Recommends ICs for desired application design
  • Incorporates loop compensation in designs
  • Compares efficiency, external component count and transformer currents for every topology (...)

Reference designs

参考设计 Download
EMC-compliant 10/100-Mbps Ethernet PHY reference design with IEEE802.3at Type-1 (≤ 12.95 W) PoE-PD
TIDA-010046 — This reference design provides a cost-optimized solution for 10 to 100 Mbps using the low-power Ethernet physical layer (PHY) DP83825 supporting 150-m reach over CAT5e cable which is beyond the standard Ethernet distance limitation of 100 m (328 feet). This design also demonstrates power (...)
document-generic Schematic
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EEPROM Programming Tool Reference Design
TIDA-01373 — The TIDA-01373 is a reference hardware and software example of a scalable programming tool for the DRV10983, DRV10975, DRV10983-Q1, and DRV10987 integrated BLDC motor drivers. These devices feature configurable EEPROM registers that need to be set to motor-specific parameters. This reference design (...)
document-generic Schematic document-generic User guide
参考设计 Download
High Voltage Ratio Vout/Vin, 2W Boost Converter Reference Design
PMP10077 When high voltage ratio between output and input is required, it's always difficult to choose the right topology. In this case, the most-simple Boost has been selected due to cost reasons. The converter runs in DCM mode therefore avoiding the Trr of the diode and shows good efficiency.
document-generic Schematic
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3 LED Driver
PMP7866 — This is an LED driver/converter that can power up to three high output LEDs. It has an input voltage range of 9V-to-16Vin and an output of 10.5Vout @ 1A.

CAD/CAE symbols

Package Pins Download
SOIC (D) 8 View options
VSSOP (DGK) 8 View options

Ordering & quality

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  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
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  • Qualification summary
  • Ongoing reliability monitoring

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Support & training

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