2V, Dual Channel 4A (IOUT), Synchronous Buck Silent Switcher 2 delivers 94% efficiency and low EMI emissions at 2MHz

Linear Technology Corporation, a subsidiary of Analog Devices, Inc., today introduced the LT8650S, a dual-channel 4A, 42V input synchronous step-down switching regulator. Its unique Silent Switcher® 2 architecture uses four internal input capacitors and two internal BST and single INTVCC capacitors to minimize thermal loop area. The LT8650S has a very well controlled switch edge and a copper pillar instead of the internal structure of the bonding wire and the overall ground plane, which greatly reduces EMI radiation. This improved EMI performance is not sensitive to PCB layout, simplifying design and reducing risk, even when using two-tier PC boards. With the 2MHz switching frequency, the LT8650S makes it easy to meet the automotive CISPR 25Class 5 peak EMI limits over the entire load range. The device also provides spread spectrum frequency modulation to further reduce EMI levels.

The LT8650S synchronous rectifier provides up to 94.6% efficiency at 2MHz switching frequency. Its 3.0V to 42V input voltage range is ideal for automotive and industrial applications. The internal high efficiency switch provides up to 4A continuous output current to the output voltage as low as 0.8V and provides a peak load up to 6A on either channel. The LT8650S Burst Mode® operation ensures a quiescent current of only 6.2μA (for both channels), making it ideal for applications where the car is always connected to the system, since such applications require extended battery life. The LT8650S achieves only 2MHz constant frequency switching from 16V input to 2V output for fast and shortest turn-on times of 40ns, enabling designers to optimize efficiency while avoiding critical noise-sensitive bands. The LT8650S 32-pin 4mm x 6mm LQFN package and high switching frequency allow the use of small external inductors and capacitors, thus forming a compact and high thermal efficiency footprint.

The LT8640S features an internal top and bottom high efficiency power switch and integrates the necessary boost diodes, oscillators, controls and logic circuitry into a single chip. The low ripple burst mode operates at low output current while maintaining high output ripple below 10mVP-P. For applications that require very fast transient response or two channels of current sharing, external VC pins can be used. For applications that require the lowest noise, the LT8650S can be configured to operate in forced continuous mode over the entire load range and have extended spectral frequency modulation. The switching frequency is programmable and synchronous in the 300kHz to 3MHz range. The special design method and the new high-speed process enable the device to achieve high efficiency over a wide input voltage range, and the LT8650S's current-mode topology enables fast transient response and excellent loop stability. Other features include chip temperature monitor, power good mark, output soft start / trace and overtemperature protection.

The LT8650SEV is available in a 4mm x 6mm LQFN package. The industrial temperature version LT8650SIV has been tested and is guaranteed to operate within the -40 ° C to 125 ° C operating junction temperature range.
Photo Description: The LT8650S reduces EMI emissions much below the CISPR 25 Class 5 specification

Performance Summary: LT8650S

Wide input voltage range: 3.0V to 42V

4A current is supplied simultaneously from each channel

Provide up to 6A on any channel

Silent Switcher2 Architecture:

In any PCB with ultra-low EMI radiation

Eliminates PCB layout sensitivity

The internal capacitors for VIN, BST, INTVCC reduce the EMI of radiation

Spread Spectrum Frequency Modulation

Ultra Low Quiescent Current Burst Mode Operation:

6.2μA IQ (adjusts 12VIN to 5VOUT1 and 3.3VOUT2)

Output ripple <10mVP-P

Optional external VC pins: for fast transient response and current sharing (50 μA IQ per channel)

Forced continuous mode

High efficiency synchronous operation:

In the 2MHz, 12VIN to 5VOUT conversion efficiency of 94.6% (in 2A)

In the 2MHz, 12VIN to 5VOUT conversion efficiency of 93.3% (in 4A)

Fast minimum on time: 40ns

Chip temperature monitor

Adjustable and synchronizable: 300kHz to 3MHz

Output soft start and trace

Small heat-resistant 4mm x 6mm 32-lead LQFN package

Find more Linear electronic component

  Author ：Brittany Antonia — WIN SOURCE ELECTRONICS

        （The author of article owns the copyright.）