Datasheet LTC3617 (Analog Devices) - 3

LTC3617
electrical characteristics The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. PVIN = SVIN = 3.3V, RT = SVIN unless otherwise specified (Notes 1, 2, 8). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
∆VFB(LINEREG) Feedback Voltage Line Regulation SVIN = PVIN = 2.25V to 5.5V, l 0.2 %/V VDDQIN = 1.5V (Notes 3, 4) ∆VFB(LOADREG) Feedback Voltage Load Regulation ITH from 0.5V to 0.9V (Notes 3, 4) 0.25 % VITH = SVIN (Note 5) 0.25 % IQ Input DC Supply Current Active Mode VFB = 0.6V, VDDQIN = 1.5V (Note 6) 1100 µA Shutdown SVIN = PVIN = 5.5V, VRUN = 0V 0.1 1 µA RDS(ON) Top Switch On-Resistance PVIN = 3.3V 35 mΩ Bottom Switch On-Resistance PVIN = 3.3V 25 mΩ ILIM Top Switch Positive Peak Current Limit Sourcing (Note 7), VFB = 0.5V 8 10 14 A Top Switch Negative Peak Current Limit Sinking (Note 7) –12 –8 –5 A gm(EA) Error Amplifier Transconductance –5µA < IITH < 5µA (Note 4) 200 µS IEAO Error Amplifier Maximum Output Current (Note 4) ±30 µA tSS Internal Soft-Start Time VFB from 0.075V to 0.675V, 0.4 0.85 2 ms VDDQIN = 1.5V fOSC Oscillator Frequency RT = 370k l 0.8 1 1.2 MHz Internal Oscillator Frequency VRT = SVIN l 1.8 2.25 2.7 MHz fSYNC Synchronization Frequency Range 0.3 4 MHz VSYNC SYNC Input Threshold High Voltage 1.2 V SYNC Input Threshold Low Voltage 0.3 V ISW(LKG) Switch Leakage Current SVIN = PVIN = 5.5V, VRUN = 0V 0.1 1 µA PGOOD Power Good Voltage Windows VDDQIN = 1.5V, Entering Window VFB Ramping Up –3.5 –5 % VFB Ramping Down 3.5 5 % VDDQIN = 1.5V, Leaving Window VFB Ramping Up 8 10 % VFB Ramping Down –8 –10 % tPGOOD Power Good Blanking Time Entering and Leaving Window 70 105 140 µs RPGOOD Power Good Pull-Down On-Resistance 8 17 33 Ω VRUN RUN voltage Input High l 1 V Input Low l 0.4 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
This parameter is tested in a feedback loop which servos VFB to may cause permanent damage to the device. Exposure to any Absolute the midpoint for the error amplifier (VITH = 0.75V). Maximum Rating condition for extended periods may affect device
Note 4:
External compensation on ITH pin. reliability and lifetime.
Note 5:
Tying the ITH pin to SVIN enables the internal compensation.
Note 2:
The LTC3617 is tested under pulsed load conditions such that
Note 6:
Dynamic supply current is higher due to the internal gate charge TJ ≈ TA. The LTC3617E is guaranteed to meet performance specifications being delivered at the switching frequency. over the 0°C to 85°C operating junction temperature range. Specifications over the –40°C to 125°C operating junction temperature range are
Note 7:
In sourcing mode the average output current is flowing out of the assured by design, characterization and correlation with statistical process SW pin. In sinking mode the average output current is flowing into the SW controls. The LTC3617I is guaranteed to meet specifications over the Pin. full –40°C to 125°C operating junction temperature range. Note that
Note 8:
This IC includes overtemperature protection that is intended the maximum ambient temperature is determined by specific operating to protect the device during momentary overload conditions. Junction conditions in conjunction with board layout, the rated package thermal temperature will exceed 125°C when overtemperature protection is active. resistance and other environmental factors. The junction temperature Continuous operation above the specified maximum operating junction (T temperature may impair device reliability. J, in °C) is calculated from the ambient temperature (TA, in °C) and power dissipation (PD, in watts) according to the formula: TJ = TA + (PD • θJA), where θJA (in °C/W) is the package thermal impedance. 3617fa 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts