Datasheet LTC3121 (Analog Devices) - 3
| Fabricante | Analog Devices |
| Descripción | 15V, 1.5A Synchronous Step-Up DC/DC Converter with Output Disconnect |
| Páginas / Página | 26 / 3 — elecTrical characTerisTics. The. denotes the specifications which apply … |
| Formato / tamaño de archivo | PDF / 973 Kb |
| Idioma del documento | Inglés |
elecTrical characTerisTics. The. denotes the specifications which apply over the full operating junction
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LTC3121
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 3). VIN = 3.6V, VOUT = 12V, RT = 57.6k unless otherwise noted. PARAMETER CONDITIONS MIN. TYP MAX UNITS
Minimum Start-Up Voltage VOUT = 0V l 1.7 1.8 V Input Voltage Range After VOUT ≥ 2.2V l 0.5 5.5 V Output Voltage Adjust Range l 2.2 15 V Feedback Voltage l 1.178 1.202 1.225 V Feedback Input Current VFB = 1.4V 1 50 nA Quiescent Current, Shutdown VSD = 0V, VOUT = 0V, Not Including Switch Leakage 0.01 1 µA Quiescent Current, Active VC = 0V, Measured On VIN, Non-Switching 500 700 µA Quiescent Current, Burst Measured on VIN, VFB > 1.4V 25 40 µA Measured on VOUT, VFB > 1.4V 10 20 µA N-channel MOSFET Switch Leakage Current VSW = 15V, VOUT = 15V, VC = 0V (Note 6) l 0.1 30 µA P-channel MOSFET Switch Leakage Current VSW = VIN = 0V, VOUT = 15V (Note 6) l 0.1 70 µA N-channel MOSFET Switch On-Resistance 0.121 Ω P-channel MOSFET Switch On-Resistance 0.188 Ω N-channel MOSFET Current Limit VIN = 3.3V l 1.5 1.8 2.7 A Maximum Duty Cycle VFB = 1.0V l 90 94 % Minimum Duty Cycle VFB = 1.4V l 0 % Switching Frequency l 0.85 1 1.15 MHz SYNC Frequency Range l 0.1 3 MHz PWM/SYNC Input High l 0.9 •VCC V PWM/SYNC Input Low l 0.1•VCC V PWM/SYNC Input Current VPWM/SYNC = 5.5V 0.01 1 µA CAP Clamp Voltage VOUT > 6.1V, Referenced to VOUT –5.2 –5.6 –6.0 V Error Amplifier Transconductance l 70 100 130 µS Error Amplifier Output Current ±25 µA Soft-Start Time 10 ms SD Input High l 1.6 V SD Input Low l 0.25 V SD Input Current VSD = 5.5V 1 2 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature range. The junction temperature (TJ in °C) is calculated from may cause permanent damage to the device. Exposure to any Absolute the ambient temperature (TA in °C) and power dissipation (PD in watts) Maximum Rating condition for extended periods may affect device according to the formula: TJ = TA + (PD • θJA) where θJA is the thermal reliability and lifetime. impedance of the package.
Note 2:
Voltage transients on the SW pin beyond the DC limit specified in
Note 4:
The LTC3121 includes overtemperature protection that is intended the Absolute Maximum Ratings are non-disruptive to normal operations to protect the device during momentary overload conditions. Junction when using good layout practices, as shown on the demo board or temperature will exceed 125°C when overtemperature shutdown is active. described in the data sheet or application notes. Continuous operation above the specified maximum operating junction
Note 3:
The LTC3121 is tested under pulsed load conditions such that temperature may result in device degradation or failure. TA ≈ TJ. The LTC3121E is guaranteed to meet performance specifications
Note 5:
Failure to solder the exposed backside of the package to the PC from 0°C to 85°C. Specifications over the –40°C to 125°C operating board ground plane will result in a thermal impedance much higher than junction temperature range are assured by design, characterization and the rated package specifications. correlation with statistical process controls. The LTC3121I is guaranteed
Note 6:
Measured using a propietary test mode to ensure anti-ringing to meet specifications over the full –40°C to 125°C operating junction switch between VIN ans SW is not active. 3121fa For more information www.linear.com/LTC3121 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Low Voltage Operation Low Noise Fixed Frequency Operation Burst Mode Operation Applications Information PCB Layout Guidelines Schottky Diode Component Selection Operating Frequency Selection Typical Applications Package Description Revision History Typical Application Related Parts
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 3). VIN = 3.6V, VOUT = 12V, RT = 57.6k unless otherwise noted. PARAMETER CONDITIONS MIN. TYP MAX UNITS
Minimum Start-Up Voltage VOUT = 0V l 1.7 1.8 V Input Voltage Range After VOUT ≥ 2.2V l 0.5 5.5 V Output Voltage Adjust Range l 2.2 15 V Feedback Voltage l 1.178 1.202 1.225 V Feedback Input Current VFB = 1.4V 1 50 nA Quiescent Current, Shutdown VSD = 0V, VOUT = 0V, Not Including Switch Leakage 0.01 1 µA Quiescent Current, Active VC = 0V, Measured On VIN, Non-Switching 500 700 µA Quiescent Current, Burst Measured on VIN, VFB > 1.4V 25 40 µA Measured on VOUT, VFB > 1.4V 10 20 µA N-channel MOSFET Switch Leakage Current VSW = 15V, VOUT = 15V, VC = 0V (Note 6) l 0.1 30 µA P-channel MOSFET Switch Leakage Current VSW = VIN = 0V, VOUT = 15V (Note 6) l 0.1 70 µA N-channel MOSFET Switch On-Resistance 0.121 Ω P-channel MOSFET Switch On-Resistance 0.188 Ω N-channel MOSFET Current Limit VIN = 3.3V l 1.5 1.8 2.7 A Maximum Duty Cycle VFB = 1.0V l 90 94 % Minimum Duty Cycle VFB = 1.4V l 0 % Switching Frequency l 0.85 1 1.15 MHz SYNC Frequency Range l 0.1 3 MHz PWM/SYNC Input High l 0.9 •VCC V PWM/SYNC Input Low l 0.1•VCC V PWM/SYNC Input Current VPWM/SYNC = 5.5V 0.01 1 µA CAP Clamp Voltage VOUT > 6.1V, Referenced to VOUT –5.2 –5.6 –6.0 V Error Amplifier Transconductance l 70 100 130 µS Error Amplifier Output Current ±25 µA Soft-Start Time 10 ms SD Input High l 1.6 V SD Input Low l 0.25 V SD Input Current VSD = 5.5V 1 2 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature range. The junction temperature (TJ in °C) is calculated from may cause permanent damage to the device. Exposure to any Absolute the ambient temperature (TA in °C) and power dissipation (PD in watts) Maximum Rating condition for extended periods may affect device according to the formula: TJ = TA + (PD • θJA) where θJA is the thermal reliability and lifetime. impedance of the package.
Note 2:
Voltage transients on the SW pin beyond the DC limit specified in
Note 4:
The LTC3121 includes overtemperature protection that is intended the Absolute Maximum Ratings are non-disruptive to normal operations to protect the device during momentary overload conditions. Junction when using good layout practices, as shown on the demo board or temperature will exceed 125°C when overtemperature shutdown is active. described in the data sheet or application notes. Continuous operation above the specified maximum operating junction
Note 3:
The LTC3121 is tested under pulsed load conditions such that temperature may result in device degradation or failure. TA ≈ TJ. The LTC3121E is guaranteed to meet performance specifications
Note 5:
Failure to solder the exposed backside of the package to the PC from 0°C to 85°C. Specifications over the –40°C to 125°C operating board ground plane will result in a thermal impedance much higher than junction temperature range are assured by design, characterization and the rated package specifications. correlation with statistical process controls. The LTC3121I is guaranteed
Note 6:
Measured using a propietary test mode to ensure anti-ringing to meet specifications over the full –40°C to 125°C operating junction switch between VIN ans SW is not active. 3121fa For more information www.linear.com/LTC3121 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Low Voltage Operation Low Noise Fixed Frequency Operation Burst Mode Operation Applications Information PCB Layout Guidelines Schottky Diode Component Selection Operating Frequency Selection Typical Applications Package Description Revision History Typical Application Related Parts