The LT3645’s main switcher utilizes a high efficiency 750mA, 450mVCESAT switch, with the necessary oscillator, control, logic circuitry and LDO integrated into a single die. Special design techniques enable high efficiency over a wide input voltage range while its current mode topology enables fast transient response and excellent loop stability. A current-limited DA pin offers an additional level of protection to improve overall reliability. The linear regulator operates from the VCC2 pin at voltages ranging from 1.2V to 16V with only a 310mV dropout voltage. Other features of the LT3645 include a power good flag, soft-start and thermal shutdown.
The LT3645EUD is offered in a 3mm x 3mm 16-lead QFN package and is priced at $2.25 each. The LT3645EMSE is offered in a 12-lead, thermally enhanced MSOP package and is priced at $2.35 each. Industrial grade versions, namely the LT3645IUD and the LT3645IMSE, are tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and are priced at $2.48 and $2.59 each, respectively. The LT3645HMSE is tested and guaranteed to operate from a -40°C to 150°C operating junction temperature and is priced at $2.84 each. All prices are for 1,000-piece quantities and all versions are available from stock. For more information, visit www.linear.com/product/LT3645.
Summary of Features: LT3645
• Wide Input Range: Operation from 3.6V to 36V, Overvoltage Lockout Protects Circuit through 55V Transients
• 500mA Output Current Switching Regulator
• Constant Switching Frequency: 750kHz
• 200mA Low Dropout Linear Regulator 1.2V to 16V Input; 0.8V to 8V Output
• 310mV Dropout Voltage VCC2 to OUT2
• Precision Undervoltage Lockout
• Short-Circuit Robust
• Internal Soft Start
• <2µA Shutdown Current
• Small Thermally Enhanced 16-Lead (3mm x 3mm) QFN & 12-Lead MSE Packages