Datasheet LTC3851A-1 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | Synchronous Step-Down Switching Regulator Controller |
| Pages / Page | 30 / 4 — elecTrical characTerisTics. The. denotes the specifications which apply … |
| File Format / Size | PDF / 442 Kb |
| Document Language | English |
elecTrical characTerisTics. The. denotes the specifications which apply over the specified operating
Model Line for this Datasheet
- LTC3851AEMSE-1#PBF LTC3851AEMSE-1#PBF LTC3851AEMSE-1#TRPBF LTC3851AEMSE-1#TRPBF LTC3851AEUD-1#PBF LTC3851AEUD-1#PBF LTC3851AEUD-1#TRPBF LTC3851AEUD-1#TRPBF LTC3851AHMSE-1#PBF LTC3851AHMSE-1#PBF LTC3851AHMSE-1#TRPBF LTC3851AHMSE-1#TRPBF LTC3851AIMSE-1#PBF LTC3851AIMSE-1#PBF LTC3851AIMSE-1#TRPBF LTC3851AIMSE-1#TRPBF LTC3851AIUD-1#PBF LTC3851AIUD-1#PBF LTC3851AIUD-1#TRPBF LTC3851AIUD-1#TRPBF LTC3851AMPMSE-1#PBF LTC3851AMPMSE-1#PBF LTC3851AMPMSE-1#TRPBF LTC3851AMPMSE-1#TRPBF
Text Version of Document
LTC3851A-1
elecTrical characTerisTics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 15V, VRUN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator and Phase-Locked Loop
fNOM Nominal Frequency RFREQ = 60k 460 500 540 kHz fLOW Lowest Frequency RFREQ = 160k 205 235 265 kHz fHIGH Highest Frequency RFREQ = 36k 690 750 810 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 100 kΩ fMODE MODE/PLLIN Minimum Input Frequency VMODE = External Clock 250 kHz MODE/PLLIN Maximum Input Frequency VMODE = External Clock 750 kHz IFREQ Phase Detector Output Current Sinking Capability fMODE > fOSC –90 µA Sourcing Capability fMODE < fOSC 75 µA
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 µA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative (UV) –12.5 –10 –7.5 % VFB Ramping Positive (OV) 7.5 10 12.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
TJ is calculated from the ambient temperature TA and power may cause permanent damage to the device. Exposure to any Absolute dissipation PD according to the following formulas: Maximum Rating condition for extended periods may affect device LTC3851AMSE-1: TJ = TA + (PD • 40°C/W) reliability and lifetime. LTC3851AUD-1: TJ = TA + (PD • 68°C/W)
Note 2:
The LTC3851A-1 is tested under pulsed load conditions such that
Note 4:
The LTC3851A-1 is tested in a feedback loop that servos V T ITH to a A ≈ TJ. The LTC3851AE-1 is guaranteed to meet performance specified voltage and measures the resultant V specifications from 0°C to 85°C junction temperature. Specifications over FB. the –40°C to 125°C operating junction temperature range are assured by
Note 5:
Dynamic supply current is higher due to the gate charge being design, characterization and correlation with statistical process controls. delivered at the switching frequency. See Applications Information. The LTC3851AI-1 is guaranteed to meet specifications over the –40°C
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay to 125°C operating junction temperature range, the LTC3851AH-1 is times are measured using 50% levels. Rise and fall times are assured by guaranteed over the –40°C to 150°C operating junction temperature range design, characterization and correlation with statistical process controls. and the LTC3851AMP-1 is tested and guaranteed over the –55°C to 150°C
Note 7:
The minimum on-time condition is specified for an inductor operating junction temperature range. High junction temperatures degrade peak-to-peak ripple current ~40% of IMAX (see Minimum On-Time operating lifetimes; operating lifetime is derated for junction temperatures Considerations in the Applications Information section). greater than 125°C. Note that the maximum ambient temperature
Note 8:
Guaranteed by design; not tested in production. consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors. 3851a1fa 4 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
elecTrical characTerisTics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 15V, VRUN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator and Phase-Locked Loop
fNOM Nominal Frequency RFREQ = 60k 460 500 540 kHz fLOW Lowest Frequency RFREQ = 160k 205 235 265 kHz fHIGH Highest Frequency RFREQ = 36k 690 750 810 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 100 kΩ fMODE MODE/PLLIN Minimum Input Frequency VMODE = External Clock 250 kHz MODE/PLLIN Maximum Input Frequency VMODE = External Clock 750 kHz IFREQ Phase Detector Output Current Sinking Capability fMODE > fOSC –90 µA Sourcing Capability fMODE < fOSC 75 µA
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 µA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative (UV) –12.5 –10 –7.5 % VFB Ramping Positive (OV) 7.5 10 12.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
TJ is calculated from the ambient temperature TA and power may cause permanent damage to the device. Exposure to any Absolute dissipation PD according to the following formulas: Maximum Rating condition for extended periods may affect device LTC3851AMSE-1: TJ = TA + (PD • 40°C/W) reliability and lifetime. LTC3851AUD-1: TJ = TA + (PD • 68°C/W)
Note 2:
The LTC3851A-1 is tested under pulsed load conditions such that
Note 4:
The LTC3851A-1 is tested in a feedback loop that servos V T ITH to a A ≈ TJ. The LTC3851AE-1 is guaranteed to meet performance specified voltage and measures the resultant V specifications from 0°C to 85°C junction temperature. Specifications over FB. the –40°C to 125°C operating junction temperature range are assured by
Note 5:
Dynamic supply current is higher due to the gate charge being design, characterization and correlation with statistical process controls. delivered at the switching frequency. See Applications Information. The LTC3851AI-1 is guaranteed to meet specifications over the –40°C
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay to 125°C operating junction temperature range, the LTC3851AH-1 is times are measured using 50% levels. Rise and fall times are assured by guaranteed over the –40°C to 150°C operating junction temperature range design, characterization and correlation with statistical process controls. and the LTC3851AMP-1 is tested and guaranteed over the –55°C to 150°C
Note 7:
The minimum on-time condition is specified for an inductor operating junction temperature range. High junction temperatures degrade peak-to-peak ripple current ~40% of IMAX (see Minimum On-Time operating lifetimes; operating lifetime is derated for junction temperatures Considerations in the Applications Information section). greater than 125°C. Note that the maximum ambient temperature
Note 8:
Guaranteed by design; not tested in production. consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors. 3851a1fa 4 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
