LT8636 42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current FEATURESDESCRIPTION n Silent Switcher ® Architecture The LT®8636 synchronous step-down regulator features n Ultralow EMI Emissions Silent Switcher architecture designed to minimize EMI n Optional Spread Spectrum Modulation emissions while delivering high efficiency at high switch- n High Efficiency at High Frequency ing frequencies. Peak current mode control with a 30ns n Up to 96% Efficiency at 1MHz, 12V minimum on-time allows high step-down ratios even at IN to 5VOUT n Up to 95% Efficiency at 2MHz, 12V high switching frequencies. IN to 5VOUT n Wide Input Voltage Range: 3.4V to 42V The LT8636’s ultralow 2.5µA quiescent current—with the n 5A Maximum Continuous, 7A Peak Transient Output output in full regulation—enables applications requiring n Ultralow Quiescent Current Burst Mode ® Operation highest efficiency at very small load currents. A CLKOUT n 2.5µA IQ Regulating 12VIN to 3.3VOUT pin enables synchronizing other regulators to the LT8636. n Output Ripple < 10mVP-P Burst Mode operation enables ultralow standby current n Fast Minimum Switch On-Time: 30ns consumption, forced continuous mode can control fre- n Low Dropout Under All Conditions: 100mV at 1A quency harmonics across the entire output load range, or n Forced Continuous Mode spread spectrum operation can further reduce EMI emis- n Adjustable and Synchronizable: 200kHz to 3MHz sions. Soft-start and tracking functionality is accessed n Output Soft-Start and Power Good via the TR/SS pin, and an accurate input voltage UVLO n Small 20-Lead 4mm × 3mm LQFN Package threshold can be set using the EN/UV pin. n AEC-Q100 Qualified for Automotive Applications All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8823345. APPLICATIONS n Automotive and Industrial Supplies n General Purpose Step-Down TYPICAL APPLICATION5V, 5A Step-Down Converter12VIN to 5VOUT Efficiency 100 3.2 VIN 5.7V TO 42V 95 2.8 4.7µF V EN/UV IN VIN EFFICIENCY 90 2.4 1µF 1µF POWER LOSS (W) GND GND 85 2.0 LT8636 BST 80 1.6 0.1µF 3.3µH VOUT SW 5V 75 1.2 EFFICIENCY (%) BIAS 5A POWER LOSS 70 0.8 INTVCC 10pF 1M 1MHz, L = 2.7µH 1µF 65 2MHz, L = 1.5µH 0.4 RT FB 100µF 3MHz, L = 1µH 60 0 41.2k GND 243k 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 LOAD CURRENT (A) 8636 TA01b f 8636 TA01a SW = 1MHz Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts
