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LM3477

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

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Product details

Vin (min) (V) 2.95 Vin (max) (V) 35 Vout (min) (V) 1.265 Vout (max) (V) 31 Iout (max) (A) 6 Iq (typ) (mA) 2 Switching frequency (min) (kHz) 500 Switching frequency (max) (kHz) 500 Features Enable Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog Control mode current mode Type Controller
Vin (min) (V) 2.95 Vin (max) (V) 35 Vout (min) (V) 1.265 Vout (max) (V) 31 Iout (max) (A) 6 Iq (typ) (mA) 2 Switching frequency (min) (kHz) 500 Switching frequency (max) (kHz) 500 Features Enable Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog Control mode current mode Type Controller
VSSOP (DGK) 8 14.7 mm² 3 x 4.9
  • 500kHz Switching Frequency
  • Adjustable Current Limit
  • 1.5% Reference
  • Thermal Shutdown
  • Frequency Compensation Optimized with a Single Capacitor and Resistor
  • Internal Softstart
  • Current Mode Operation
  • Undervoltage Lockout with Hysteresis
  • 8-lead (VSSOP-8) Package

All trademarks are the property of their respective owners.

  • 500kHz Switching Frequency
  • Adjustable Current Limit
  • 1.5% Reference
  • Thermal Shutdown
  • Frequency Compensation Optimized with a Single Capacitor and Resistor
  • Internal Softstart
  • Current Mode Operation
  • Undervoltage Lockout with Hysteresis
  • 8-lead (VSSOP-8) Package

All trademarks are the property of their respective owners.

The LM3477/A is a high-side N-channel MOSFET switching regulator controller. It can be used in topologies requiring a high side MOSFET such as buck, inverting (buck-boost) and zeta regulators. The LM3477/A's internal push pull driver allows compatibility with a wide range of MOSFETs. This, the wide input voltage range, use of discrete power components and adjustable current limit allows the LM3477/A to be optimized for a wide variety of applications.

The LM3477/A uses a high switching frequency of 500kHz to reduce the overall solution size. Current-mode control requires only a single resistor and capacitor for frequency compensation. The current mode architecture also yields superior line and load regulation and cycle-by-cycle current limiting. A 5µA shutdown state can be used for power savings and for power supply sequencing. Other features include internal soft-start and output over voltage protection. The internal soft-start reduces inrush current. Over voltage protection is a safety feature to ensure that the output voltage stays within regulation.

The LM3477A is similar to the LM3477. The primary difference between the two is the point at which the device transitions into hysteretic mode. The hysteretic threshold of the LM3477A is one-third of the LM3477.

The LM3477/A is a high-side N-channel MOSFET switching regulator controller. It can be used in topologies requiring a high side MOSFET such as buck, inverting (buck-boost) and zeta regulators. The LM3477/A's internal push pull driver allows compatibility with a wide range of MOSFETs. This, the wide input voltage range, use of discrete power components and adjustable current limit allows the LM3477/A to be optimized for a wide variety of applications.

The LM3477/A uses a high switching frequency of 500kHz to reduce the overall solution size. Current-mode control requires only a single resistor and capacitor for frequency compensation. The current mode architecture also yields superior line and load regulation and cycle-by-cycle current limiting. A 5µA shutdown state can be used for power savings and for power supply sequencing. Other features include internal soft-start and output over voltage protection. The internal soft-start reduces inrush current. Over voltage protection is a safety feature to ensure that the output voltage stays within regulation.

The LM3477A is similar to the LM3477. The primary difference between the two is the point at which the device transitions into hysteretic mode. The hysteretic threshold of the LM3477A is one-third of the LM3477.

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* Data sheet LM3477 High Efficiency High-Side N-Channel Controller for Switching Regulator datasheet (Rev. K) 21 Mar 2013
User guide LM3477 Buck Controller Evaluation Module User's Guide (Rev. F) PDF | HTML 01 Feb 2022
Selection guide Power Management Guide 2018 (Rev. R) 25 Jun 2018
Analog Design Journal Reduce buck-converter EMI and voltage stress by minimizing inductive parasitics 21 Jul 2016

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