Datasheet LTC3850, LTC3850-1 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Dual, 2-Phase Synchronous Step-Down Switching Controller |
| Pages / Page | 38 / 5 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| Revision | D |
| File Format / Size | PDF / 1.2 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the full operating
Model Line for this Datasheet
- LTC3850EGN#PBF LTC3850EGN#TRPBF LTC3850EGN#WPBF LTC3850EGN#WTRPBF LTC3850EGN-1#PBF LTC3850EGN-1#TRPBF LTC3850EGN-1#WPBF LTC3850EGN-1#WTRPBF LTC3850EUF#PBF LTC3850EUF#TRPBF LTC3850EUFD#PBF LTC3850EUFD#TRPBF LTC3850IGN#PBF LTC3850IGN#TRPBF LTC3850IGN#WPBF LTC3850IGN#WTRPBF LTC3850IGN-1#PBF LTC3850IGN-1#TRPBF LTC3850IGN-1#WPBF LTC3850IGN-1#WTRPBF LTC3850IUF#PBF LTC3850IUF#TRPBF LTC3850IUFD#PBF LTC3850IUFD#TRPBF
Text Version of Document
link to page 2 link to page 13 link to page 13 LTC3850/LTC3850-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 15V, VRUN1,2 = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VFREQ = 1.2V 450 500 550 kHz fLOW Lowest Frequency VFREQ = 0V 210 250 290 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 700 780 860 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 250 kΩ IFREQ Phase Detector Output Current Sinking Capability fMODE < fOSC –13 µA Sourcing Capability fMODE > fOSC 13 µA
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±2 µA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative –5 –7.5 –10 % VFB Ramping Positive 5 7.5 10 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings LTC3850GN: TJ = TA + (PD • 95°C/W) may cause permanent damage to the device. Exposure to any Absolute LTC3850UF: TJ = TA + (PD • 37°C/W) Maximum Rating condition for extended periods may affect device LTC3850UFD: TJ = TA + (PD • 43°C/W) reliability and lifetime.
Note 4:
The LTC3850 is tested in a feedback loop that servos VITH1,2 to a
Note 2:
The LTC3850E/LTC3850E-1 are guaranteed to meet performance specified voltage and measures the resultant VFB1,2. specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
Note 5:
Dynamic supply current is higher due to the gate charge being operating temperature range are assured by design, characterization and delivered at the switching frequency. See Applications Information. correlation with statistical process controls. The LTC3850I/LTC3850I-1
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay are guaranteed to meet performance specifications over the –40°C to 85°C times are measured using 50% levels. operating temperature range.
Note 7:
The minimum on-time condition is specified for an inductor
Note 3:
TJ is calculated from the ambient temperature TA and power peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time dissipation PD according to the following formulas: Considerations in the Applications Information section).
Note 8:
VSENSE(MAX) defaults to 50mV typical for the LTC3850-1.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Output Current Efficiency vs Output Current Efficiency and Power Loss and Mode and Mode vs Input Voltage
100 100 100 2000 VIN = 12V VOUT = 3.3V 90 VOUT = 1.8V 90 BURST IOUT = 2A BURST 80 80 95 1500 70 70 POWER LOSS (mW) EFFICIENCY 60 DCM 60 DCM 50 50 90 1000 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) POWER LOSS 30 CCM 30 CCM 85 500 20 20 10 10 VIN = 12V V 0 OUT = 3.3V 0 80 0 10 100 1000 10000 10 100 1000 10000 5 10 15 20 25 LOAD CURRENT (mA) LOAD CURRENT (mA) INPUT VOLTAGE (V) 38501 G01 38501 G02 38501 G03 CIRCUIT OF FIGURE 14 CIRCUIT OF FIGURE 14 CIRCUIT OF FIGURE 14 Rev. D For more information www.analog.com 5 Document Outline Features Applications Typical Application Description 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 full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 15V, VRUN1,2 = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VFREQ = 1.2V 450 500 550 kHz fLOW Lowest Frequency VFREQ = 0V 210 250 290 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 700 780 860 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 250 kΩ IFREQ Phase Detector Output Current Sinking Capability fMODE < fOSC –13 µA Sourcing Capability fMODE > fOSC 13 µA
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±2 µA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative –5 –7.5 –10 % VFB Ramping Positive 5 7.5 10 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings LTC3850GN: TJ = TA + (PD • 95°C/W) may cause permanent damage to the device. Exposure to any Absolute LTC3850UF: TJ = TA + (PD • 37°C/W) Maximum Rating condition for extended periods may affect device LTC3850UFD: TJ = TA + (PD • 43°C/W) reliability and lifetime.
Note 4:
The LTC3850 is tested in a feedback loop that servos VITH1,2 to a
Note 2:
The LTC3850E/LTC3850E-1 are guaranteed to meet performance specified voltage and measures the resultant VFB1,2. specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
Note 5:
Dynamic supply current is higher due to the gate charge being operating temperature range are assured by design, characterization and delivered at the switching frequency. See Applications Information. correlation with statistical process controls. The LTC3850I/LTC3850I-1
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay are guaranteed to meet performance specifications over the –40°C to 85°C times are measured using 50% levels. operating temperature range.
Note 7:
The minimum on-time condition is specified for an inductor
Note 3:
TJ is calculated from the ambient temperature TA and power peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time dissipation PD according to the following formulas: Considerations in the Applications Information section).
Note 8:
VSENSE(MAX) defaults to 50mV typical for the LTC3850-1.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Output Current Efficiency vs Output Current Efficiency and Power Loss and Mode and Mode vs Input Voltage
100 100 100 2000 VIN = 12V VOUT = 3.3V 90 VOUT = 1.8V 90 BURST IOUT = 2A BURST 80 80 95 1500 70 70 POWER LOSS (mW) EFFICIENCY 60 DCM 60 DCM 50 50 90 1000 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) POWER LOSS 30 CCM 30 CCM 85 500 20 20 10 10 VIN = 12V V 0 OUT = 3.3V 0 80 0 10 100 1000 10000 10 100 1000 10000 5 10 15 20 25 LOAD CURRENT (mA) LOAD CURRENT (mA) INPUT VOLTAGE (V) 38501 G01 38501 G02 38501 G03 CIRCUIT OF FIGURE 14 CIRCUIT OF FIGURE 14 CIRCUIT OF FIGURE 14 Rev. D For more information www.analog.com 5 Document Outline Features Applications Typical Application Description 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
