Analog Devices announces 42V, 15A Synchronous Step-Down regulator Silent Switcher 2

Analog Devices announced the release of a new synchronous step-down regulator, LT8648S, that features second generation Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at high switching frequencies. This includes the integration of input and boost capacitors to optimize all the fast current loops inside and make it easy to achieve advertised EMI performance by reducing layout sensitivity. This performance makes the LT8648S ideal for noise sensitive applications and environments.

Typical Application Schematic.

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 25 ns minimum on-time allows high step down ratios even at high switching frequencies. External compensation via the V_C pin allows for fast transient response at high switching frequencies. The V_C pin also enables current sharing and a CLKOUT pin enables synchronizing other regulators to the LT8648S.

Burst Mode operation enables low standby current consumption, forced continuous mode can control frequency harmonics across the entire output load range, or spread spectrum operation can further reduce EMI emissions. Soft-start and tracking functionality is accessed via the SS pin, and an accurate input voltage UVLO threshold can be set using the EN/UV pin.

2 VIN to 5 VOUT Efficiency vs. Load Current.

Features

• Silent Switcher 2 Architecture
• Ultralow EMI Emissions on Any PCB
• Eliminates PCB Layout Sensitivity
• Internal Bypass Capacitors Reduce Radiated EMI
• Optional Spread Spectrum Modulation
• High Efficiency at High Frequency
• Up to 95.5% Efficiency at 1 MHz, 12 V_IN to 5 V_OUT
• Up to 93% Efficiency at 2 MHz, 12 V_IN to 5 V_OUT
• Wide Input Voltage Range: 3 V to 42 V
• 15 A Output Current
• Low Quiescent Current Burst Mode® Operation
• 100 µA I_Q Regulating 12 V_IN to 5 V_OUT
• Output Ripple < 10 mV_P-P
• External Compensation: Fast Transient Response and Current Sharing
• Fast Minimum Switch On-Time: 25 ns
• Low Dropout Under All Conditions: 35 mV at 1 A
• Forced Continuous Mode
• Adjustable and Synchronizable: 200 kHz to 2.2 MHz
• Output Soft-Start and Power Good
• Safely Tolerates High Reverse Current
• Small 36-Lead 7 mm × 4 mm LQFN Package
• AEC-Q100 Qualification in Progress

Applications

• Automotive and Industrial Supplies
• General Purpose Step-Down