Features and Benefits
- Silent Switcher®2 Architecture:
- Ultralow EMI on Any PCB
- Eliminates PCB Layout Sensitivity
- Internal Bypass Capacitors Reduce Radiated EMI
- Spread Spectrum Frequency Modulation
- 8.5A DC from Each Channel Simultaneously
- Up to 12A on Either Channel
- Ultralow Quiescent Current Burst Mode® Operation:
- 16µA IQ Regulating 12VIN to 3.3VOUT (Both Channels)
- Output Ripple <10mVP-P
- ±1.2% 600mV Feedback Voltage with Remote Sense
- Output Current Monitor Pins with Current Limiting
- Forced Continuous Mode
- CLKOUT for Up to 4-Phase Operation
- 93.6% Efficiency at 6A, 3.3VOUT from 12VIN at 1MHz
- 85.6% Efficiency at 6A, 1.0VOUT from 12VIN at 1MHz
- Fast Minimum Switch-On Time: 20ns
- Adjustable and Synchronizable: 300kHz to 3MHz
- Small 4mm × 7mm 36-Pin LQFN Package
- AEC-Q100 Qualification for Automotive Applications in Progress
The LT8652S is a dual step-down regulator that delivers up to 8.5A of continuous current from both channels and supports loads up to 12A from each channel. The LT8652S uses second generation Silent Switcher technology including integrated bypass capacitors to deliver a high frequency, high efficiency, small solution with excellent EMI performance. The LT8652S is ideal for noise sensitive applications such as PLLs and high bandwidth data and communications systems.
The fast, clean, low overshoot switching edges enable high efficiency operation even at high switching frequencies, enabling a wide control loop bandwidth for fast transient response. Output current monitoring and limiting allows inductors to be selected for the maximum output current in a given application. Differential output voltage sensing provides accurate voltage regulation at the point of load for high current applications. The two channels can be combined to deliver 17A, and two LT8652S ICs can be combined for a 4-phase, 34A supply.
- Server Power Applications
- General Purpose Step-Down
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2523A is an 18V, 8.5A (continuous)/12A (peak) synchronous step-down Silent Switcher® with 16µA quiescent current featuring the LT8652S. The LT8652S is a compact, high efficiency, high speed synchronous monolithic step-down switching with the second generation Silent Switcher structure that minimizes EMI and reduces PCB layout sensitivity. Top and bottom power switches, compensation components and other necessary circuits are inside of the LT8652S to minimize external components and simplify design. The demo board has two outputs: 3.3V and 1.2V from a 3.6V to 18V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies.
The SYNC pin on the demo board is grounded by default for low ripple Burst Mode® operation. Move JP2 to FCM without SSM position can change the operation mode to forced continuous mode operation. Once JP2 is on FCM with SSM position, VCC is applied to the SYNC pin for low EMI spread spectrum operation. To synchronous to an external clock, move JP2 to SYNC and apply the external clock to the SYNC turret.
The demonstration circuit 2523A runs at 2MHz to minimize solution size. The peak efficiency is 90%. The IC temperature rise is less than 70°C when both channels run at full load, 8.5A each, at 2MHz.
The demo board has EMI filters installed for both channels. To use the EMI filter, the input should be tied to VEMI1/VEMI2, not VIN1/VIN2.
The LT8652S data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2523A.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.