LT3791-1 e lecTrical characTerisTics The l denotes the specifications which apply over the full operatingjunction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 12V, VEN/UVLO = 12V unless otherwise noted.PARAMETERCONDITIONSMINTYPMAXUNITS C/10 Rising Threshold (VFB) V(ISP-ISN) = 0V l 1.127 1.15 1.173 V C/10 Falling Threshold (VFB) l 1.078 1.1 1.122 V C/10 Falling Threshold (V(ISP-ISN)) VFB = 1.2V 5 10 15 mV SHORT Falling Threshold (VFB) 380 400 450 mV C/10 Pin Output Impedance 1.1 2.0 kΩ SHORT Pin Output Impedance 1.1 2.0 kΩ SS Latch-Off Threshold 1.75 V SS Reset Threshold 0.2 V Oscillator Switching Frequency RT = 147k 190 200 210 kHz RT = 59.0k 380 400 420 kHz RT = 29.1k 665 700 735 kHz SYNC Frequency 200 700 kHz SYNC Pin Resistance to GND 90 kΩ SYNC Threshold Voltage 0.3 1.5 V Internal VCC Regulator INTVCC Regulation Voltage 4.8 5 5.2 V Dropout (VIN – INTVCC) IINTVCC = –10mA, VIN = 5V 240 350 mV INTVCC Undervoltage Lockout 3.1 3.5 3.9 V INTVCC Current Limit VINTVCC = 4V 67 mA PWM PWM Threshold Voltage 0.3 1.5 V PWM Pin Resistance to GND 90 kΩ PWMOUT Pull-Up Resistance 10 20 Ω PWMOUT Pull-Down Resistance 5 10 Ω NMOS Drivers TG1, TG2 Gate Driver On-Resistance VBST – VSW = 5V Gate Pull-Up 2.6 Ω Gate Pull-Down 1.7 Ω BG1, BG2 Gate Driver On-Resistance VINTVCC = 5V Gate Pull-Up 3 Ω Gate Pull-Down 1.2 Ω TG Off to BG On Delay CL = 3300pF 60 ns BG Off to TG On Delay CL = 3300pF 60 ns TG1, TG2, tOFF(MIN) RT = 59.0k 240 320 ns Note 1: Stresses beyond those listed under Absolute Maximum Ratings operating junction temperature range. The LT3791MP-1 is guaranteed may cause permanent damage to the device. Exposure to any Absolute to meet performance specifications over the –55°C to 150°C operating Maximum Rating condition for extended periods may affect device junction temperature range. High junction temperatures degrade operating reliability and lifetime. lifetimes. Operating lifetime is derated for junction temperatures greater Note 2: The LT3791E-1 is guaranteed to meet performance from than 125°C. 0°C to 125°C junction temperature. Specification over the -40°C to Note 3: The LT3791-1 includes overtemperature protection that is intended 125°C operating junction temperature range are assured by design, to protect the device during momentary overload conditions. Junction characterization and correlation with statistical process controls. temperature will exceed the maximum operating junction temperature The LT3791I-1 is guaranteed to meet performance specifications over the when overtemperature protection is active. Continuous operation above –40°C to 125°C operating junction temperature range. The LT3791H-1 is the specified absolute maximum operating junction temperature may guaranteed to meet performance specifications over the –40°C to 150°C impair device reliability. 37911fb 4 For more information www.linear.com/LT3791-1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Typical Application Related Parts