Datasheet LT8620 (Analog Devices)

LT8620 65V, 2A Synchronous Step-Down Regulator with 2.5µA Quiescent Current
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 3.4V to 65V
The LT®8620 is a compact, high efficiency, high speed n
Ultralow Quiescent Current Burst Mode
®
Operation:
synchronous monolithic step-down switching regulator n
2.5μA IQ Regulating 12VIN to 3.3VOUT
that accepts a wide input voltage range up to 65V, and n
Output Ripple < 10mVP-P
consumes only 2.5µA of quiescent current. Top and bottom n
High Efficiency Synchronous Operation:
power switches are included with all necessary circuitry n
94% Efficiency at 1A, 12VIN to 5VOUT
to minimize the need for external components. Low ripple n
92% Efficiency at 1A, 12VIN to 3.3VOUT
Burst Mode operation enables high efficiency down to n
Fast 30ns Minimum Switch-On Time
very low output currents while keeping the output ripple n
Low Dropout Under All Conditions: 250mV at 1A
below 10mVP-P. A SYNC pin allows synchronization to an n
Safely Tolerates Inductor Saturation in Overload
external clock. Internal compensation with peak current n Low EMI mode topology allows the use of small inductors and n Adjustable and Synchronizable: 200kHz to 2.2MHz results in fast transient response and good loop stability. n Accurate 1V Enable Pin Threshold The EN/UV pin has an accurate 1V threshold and can be n Internal Compensation used to program VIN undervoltage lockout or to shut down n Output Soft-Start and Tracking the LT8620 reducing the input supply current to 1µA. A n capacitor on the TR/SS pin programs the output voltage Small Thermally Enhanced 16-Lead MSOP and ramp rate during start-up. The PG flag signals when V 24-Lead 3mm × 5mm QFN Packages OUT is within ±9% of the programmed output voltage as well as fault conditions. The LT8620 is available in small 16-Lead
APPLICATIONS
MSOP and 3mm × 5mm QFN packages with exposed pads n Automotive and Industrial Supplies for low thermal resistance. n General Purpose Step-Down L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n GSM Power Supplies of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION Efficiency at 5VOUT 5V 2A Step-Down Converter
100 V 95 IN VIN BST 5.5V TO 65V 0.1µF 90 4.7µF EN/UV 4.7µH VOUT 85 PG SW 5V LT8620 2A 80 SYNC BIAS 47µF 10nF 75 1M TR/SS FB 70 1µF EFFICIENCY (%) 10pF 65 INTVCC 60 fSW = 700kHz RT GND 55 VIN = 12V VIN = 24V 60.4k 243k 50 0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 fSW = 700kHz 8620 TA01a LOAD CURRENT (A) 8620 TA01b 8620fa For more information www.linear.com/LT8620 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts