Datasheet LTC3875 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Dual, 2-Phase, Synchronous Controller with Low Value DCR Sensing and Temperature Compensation |
| Pages / Page | 46 / 5 — ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 997 Kb |
| Document Language | English |
ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply over the specified operating
Model Line for this Datasheet
Text Version of Document
LTC3875
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, VRUN1,2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 38V 5.3 5.5 5.7 V VLDO INT INTVCC Load Regulation ICC = 0mA to 20mA 0.5 2.0 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive l 4.5 4.7 V VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5.5V 50 100 mV VLDOHYS EXTVCC Hysteresis 200 mV
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VFREQ = 1.2V 450 500 550 kHz fLOW Lowest Frequency VFREQ = 0V 220 250 270 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 650 720 790 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 250 kΩ IFREQ Frequency Setting Current 9.5 10 10.5 µA CLKOUT Phase (Relative to Controller 1) PHASMD = GND 60 Deg PHASMD = FLOAT 90 Deg PHASMD = INTVCC 120 Deg CLK High Clock Output High Voltage VINTVCC = 5.5V 4.5 5.5 V CLK Low Clock Output Low Voltage 0.2 V VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5.5V ±2 µA V + PG PGOOD Trip Level, Either Controller VOSNS with Respect to Set Output Voltage V + OSNS Ramping Negative –7.5 % V + OSNS Ramping Positive 7.5 %
On-Chip Driver
TG RUP TG Pull-Up RDS(ON) TG High 2.6 Ω TG RDOWN TG Pull-Down RDS(ON) TG Low 1.5 Ω BG RUP BG Pull-Up RDS(ON) BG High 2.4 Ω BG RDOWN BG Pull-Down RDS(ON) BG Low 1.1 Ω
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 formula: Maximum Rating condition for extended periods may affect device TJ = TA + (PD • θJA°C/W) reliability and lifetime. where θJA = 44°C/W for the 5mm × 5mm QFN and θJA = 33°C/W for
Note 2:
The LTC3875 is tested under pulsed load conditions such that the 6mm × 6mm QFN. TJ ≈ TA. The LTC3875E is guaranteed to meet specifications from
Note 4:
The LTC3875 is tested in a feedback loop that servos V 0°C to 85°C junction temperature. Specifications over the –40°C to ITH1,2 to a specified voltage and measures the resultant V + OSNS1,2 . 125°C operating junction temperature range are assured by design,
Note 5:
Dynamic supply current is higher due to the gate charge being characterization and correlation with statistical process controls. The delivered at the switching frequency. See Applications Information. LTC3875I is guaranteed over the full –40° to 125° operating junction temperature range. Note that the maximum ambient temperature
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels. consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal
Note 7:
The minimum on-time condition is specified for an inductor impedance and other environmental factors. peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time Considerations in the Applications Information section).
Note 8:
Guaranteed by design. 3875fb For more information www.linear.com/LTC3875 5 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 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, VRUN1,2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 38V 5.3 5.5 5.7 V VLDO INT INTVCC Load Regulation ICC = 0mA to 20mA 0.5 2.0 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive l 4.5 4.7 V VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5.5V 50 100 mV VLDOHYS EXTVCC Hysteresis 200 mV
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VFREQ = 1.2V 450 500 550 kHz fLOW Lowest Frequency VFREQ = 0V 220 250 270 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 650 720 790 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 250 kΩ IFREQ Frequency Setting Current 9.5 10 10.5 µA CLKOUT Phase (Relative to Controller 1) PHASMD = GND 60 Deg PHASMD = FLOAT 90 Deg PHASMD = INTVCC 120 Deg CLK High Clock Output High Voltage VINTVCC = 5.5V 4.5 5.5 V CLK Low Clock Output Low Voltage 0.2 V VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5.5V ±2 µA V + PG PGOOD Trip Level, Either Controller VOSNS with Respect to Set Output Voltage V + OSNS Ramping Negative –7.5 % V + OSNS Ramping Positive 7.5 %
On-Chip Driver
TG RUP TG Pull-Up RDS(ON) TG High 2.6 Ω TG RDOWN TG Pull-Down RDS(ON) TG Low 1.5 Ω BG RUP BG Pull-Up RDS(ON) BG High 2.4 Ω BG RDOWN BG Pull-Down RDS(ON) BG Low 1.1 Ω
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 formula: Maximum Rating condition for extended periods may affect device TJ = TA + (PD • θJA°C/W) reliability and lifetime. where θJA = 44°C/W for the 5mm × 5mm QFN and θJA = 33°C/W for
Note 2:
The LTC3875 is tested under pulsed load conditions such that the 6mm × 6mm QFN. TJ ≈ TA. The LTC3875E is guaranteed to meet specifications from
Note 4:
The LTC3875 is tested in a feedback loop that servos V 0°C to 85°C junction temperature. Specifications over the –40°C to ITH1,2 to a specified voltage and measures the resultant V + OSNS1,2 . 125°C operating junction temperature range are assured by design,
Note 5:
Dynamic supply current is higher due to the gate charge being characterization and correlation with statistical process controls. The delivered at the switching frequency. See Applications Information. LTC3875I is guaranteed over the full –40° to 125° operating junction temperature range. Note that the maximum ambient temperature
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels. consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal
Note 7:
The minimum on-time condition is specified for an inductor impedance and other environmental factors. peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time Considerations in the Applications Information section).
Note 8:
Guaranteed by design. 3875fb For more information www.linear.com/LTC3875 5 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 Related Parts
