Datasheet LTC3122 (Analog Devices) - 3

LTC3122
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating 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 l 0.1 30 µA P-channel MOSFET Switch Leakage Current VSW = 0V, VOUT = 15V, VSD = 0V 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 l 2.5 3.5 4.5 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 VCC Regulation Voltage VIN < 2.8V, VOUT > 5V 4 4.25 4.5 V Error Amplifier Transconductance l 70 95 120 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 LTC3122H is guaranteed to meet specifications may cause permanent damage to the device. Exposure to any Absolute over the full –40°C to 150°C operating junction range. The junction Maximum Rating condition for extended periods may affect device temperature (TJ in °C) is calculated from the ambient temperature (TA in reliability and lifetime. °C) and power dissipation (PD in Watts) according to the formula: TJ = TA
Note 2:
Voltage transients on the SW pin beyond the DC limit specified in + (PD • θJA) where θJA is the thermal impedance of the package. the Absolute Maximum Ratings are non-disruptive to normal operations
Note 4:
The LTC3122 includes overtemperature protection that is intended when using good layout practices, as shown on the demo board or to protect the device during momentary overload conditions. Junction described in the data sheet or application notes. temperature will exceed 150°C when overtemperature shutdown is active.
Note 3:
The LTC3122 is tested under pulsed load conditions such that Continuous operation above the specified maximum operating junction T temperature may result in device degradation or failure. A ≈ TJ. The LTC3122E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 125°C operating
Note 5:
Failure to solder the exposed backside of the package to the PC junction temperature range are assured by design, characterization and board ground plane will result in a thermal impedance much higher than correlation with statistical process controls. The LTC3122I is guaranteed the rated package specifications. to meet specifications over the full –40°C to 125°C operating junction 3122fa For more information www.linear.com/LTC3122 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 Applications Information Typical Applications Package Description Typical Application Related Parts