Analog Devices Inc. LT8650S Synchronous Step-Down Silent Switcher® 2

Analog Devices Inc. LT8650S Synchronous Step-Down Silent Switcher® 2 is a dual step-down regulator with a wide input voltage range of 3V to 42V, ideal for automotive, industrial, and other step-down applications. The LT8650S features a low 6.2µA quiescent current with the outputs in regulation, a critical feature in automotive environments where always-on systems can drain the battery even when the car is not running. The Silent Switcher^®2 architecture of the LT8650S minimizes EMI emissions while delivering high efficiency at high switching frequencies. This includes integration of bypass capacitors to optimize high frequency current loops and make it easy to achieve advertised EMI performance by eliminating layout sensitivity.

The LT8650S delivers up to 4A of continuous current from both channels and supports loads up to 6A from each channel. The fast, clean, low-overshoot switching edges enable high efficiency operation even at high switching frequencies, leading to a small overall solution size. Peak current mode control with a 40ns minimum on-time allows high step down ratios at high switching frequencies.

Burst Mode operation results in high efficiency at low output currents, forced continuous mode allows fixed switching frequency operation over the entire output load range, and spread spectrum operation can further reduce EMI emissions. External VC pins allow optimal loop compensation for fast transient response. The VC pins can also be used for current sharing and the CLKOUT pin enables synchronizing two LT8650S chips to generate a 4-phase, 16A supply.

Features

Silent Switcher 2 Architecture
- Ultralow EMI on Any PCB n 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 BurstMode^® Operation
- 6.2μA IQ Regulating 12VIN to 5VOUT1 and 3.3VOUT2
- Output Ripple <10mVP-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
Adjustable and Synchronizable: 300kHz to 3MHz
Package Type: LQFN-32
Package Dimensions: 4mm × 6mm
RoHS and WEEE Compliant

Applications

General Purpose Step-Down

Automotive and Industrial Supplies

Videos

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