Datasheet LT8650S-1 (Analog Devices)

LT8650S-1 Dual Channel 4A, 42V, Synchronous Step-Down Silent Switcher 2 with 6.2µA Quiescent Current
FEATURES DESCRIPTION
n Silent Switcher®2 Architecture: The LT®8650S-1 is a dual step-down regulator that delivers n Ultralow EMI on Any PCB up to 4A of continuous current from both channels and n Eliminates PCB Layout Sensitivity supports loads up to 6A from each channel. The LT8650S-1 n Internal Bypass Capacitors Reduce Radiated EMI features the second generation Silent Switcher architecture n Optional Spread Spectrum Modulation to minimize EMI emissions while delivering high efficiency n 4A DC from Each Channel Simultaneously at high switching frequencies. This includes integration of n Up to 6A on Either Channel bypass capacitors to optimize high frequency current loops n Ultralow Quiescent Current Burst Mode® Operation: and make it easy to achieve advertised EMI performance n 6.2μA IQ Regulating 12VIN to 5VOUT1 and 3.3VOUT2 by eliminating layout sensitivity. n Output Ripple <10mVP-P The LT8650S-1 is the H-grade version of the LT8650S. n Optional External VC Pin: Fast Transient Response The internal capacitors are X8R type to achieve the 150°C and Current Sharing (Extra 50µA IQ/Channel) rating. This requires the use of an external boost capacitor n Forced Continuous Mode between the BST and SW nodes. n High Efficiency at High Frequency n 94.6% Efficiency at 2A, 5V Burst Mode operation features a 6.2μA quiescent current OUT from 12VIN at 2MHz n 93.3% Efficiency at 4A, 5V resulting in high efficiency at low output currents, forced OUT from 12VIN at 2MHz n Fast Minimum Switch-On Time: 40ns continuous mode allows fixed switching frequency opera- n Wide Input Voltage Range: 3.0V to 42V tion over the entire output load range, and spread spectrum n Adjustable and Synchronizable: 300kHz to 3MHz operation can further reduce EMI emissions. External VC n Small 4mm × 6mm 32-Pin LQFN Package pins allow optimal loop compensation for fast transient response. The VC pins can also be used for current sharing
APPLICATIONS
and the CLKOUT pin enables synchronizing two LT8650S-1 chips to generate a 4-phase, 16A supply. n General Purpose Step-Down n Automotive and Industrial Supplies All registered trademarks and trademarks are the property of their respective owners. Protected by U.S patents, including 8823345.
TYPICAL APPLICATION 5V/4A, 3.3V/4A 2MHz Step-Down Converter Efficiency
V 100 IN1 VIN1 V VIN2 IN2 5.4V TO 42V 3.7V TO 42V 95 4.7µF EN/UV1 EN/UV2 4.7µF 90 BST1 BST2 85 V 0.1µF 1µH 0.1µF 1µH OUT1 VOUT2 80 LT8650S-1 5V SW1 SW2 3.3V 75 4A 47µF 4A 1M 4.7pF 47µF ×2 4.7pF 1M ×2 70 FB1 FB2 65 EFFICIENCY (%) 191k 60 V 316k CC VC1 VC2 VCC 55 SS1 SS2 50 10nF 10nF V 45 IN1 = VIN2 = 12V CH1 5V fSW = 2MHz CH2 3.3V BIAS 40 0 1 2 3 4 5 6 RT VCC GND SYNC LOAD CURRENT (A) 8650s1 TA01b 15k 1µF 8650s1 TA01a fSW = 2MHz Rev 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts