New Industry Products

Automotive and Industrial Dual channel 4A, 42V, Synchronous Step-down Converter

January 14, 2019 by Scott McMahan

Analog Devices has introduced a dual channel 4A, 42V, synchronous step-down converter with 6.2µA quiescent current for automotive and industrial power supplies. The LT®8650S-1 features the second generation of the company's proprietary Silent Switcher® architecture, which results in ultralow EMI on any PCB.

Also, internal bypass capacitors reduce radiated EMI. The exclusive architecture comes with optional spread spectrum modulation, and according to the company, the design eliminates PCB layout sensitivity. Furthermore, the converter can generate 4A DC from each channel simultaneously and up to 6A on either channel individually.

The unique architecture enables the company's Ultralow Quiescent Current Burst Mode® Operation with 6.2µA Iq regulating, and12Vin to 5Vout1 and 3.3Vout2. In this mode, the output ripple is less than 10mVp-p. The converter offers an optional external Vc pin which results in fast transient response and allows current sharing with an extra 50µA Iq per channel.

The device design enables forced continuous mode operation, and the company says that this mode offers high efficiency at high frequency.

At 2A, it delivers 94.6% efficiency with 5Vout from 12Vin at 2MHz, and at 4A, it provides 93.3% efficiency with 5Vout from 12Vin at 2MHz. Analog Devices says it offers a fast minimum switch-on time of 40ns and allows a wide input voltage range of 3.0V to 42V.

Efficiency of Converter

The converter comes in a small 4mm × 6mm 32-Pin LQFN package and is adjustable and synchronizable from 300kHz to 3MHz. The CLKout pin enables synchronizing of two LT8650S-1 chips to produce a 4-phase, 16A supply.

The company says that the LT®8650S-1 is in production.

Converter Features 

  • Dual Channel 4A, 42V, Synchronous Step-Down
  • Silent Switcher 2 with 6.2µA Quiescent Current 5V/4A, 3.3V/4A 2MHz Step-Down Converter Efficiency
  • Silent Switcher®2 Architecture:
    • Ultralow EMI on Any PCB
    • Eliminates PCB Layout Sensitivity
    • Internal Bypass Capacitors Reduce Radiated EMI
  • Optional Spread Spectrum Modulation
  • 4A DC from Each Channel Simultaneously
  • Up to 6A on Either Channel
  • Ultralow Quiescent Current Burst Mode® Operation:
    • 6.2μA IQ Regulating 12VIN to 5Vout1 and 3.3Vout2
    • Output Ripple <10m VP-P
  • Optional External VC Pin:
  • Fast Transient Response and Current Sharing (Extra 50µA IQ/Channel)
  • Forced Continuous Mode
  • High Efficiency at High Frequency
  • 94.6% Efficiency at 2A, 5VOUT from 12VIN at 2MHz
  • 93.3% Efficiency at 4A, 5VOUT from 12VIN at 2MHz
  • Fast Minimum Switch-On Time: 40ns
  • Wide Input Voltage Range:
  • 3.0V to 42V n Adjustable and Synchronizable: 300kHz to 3MHz
  • Small 4mm × 6mm 32-Pin LQFN Package