Datasheet LTC3856 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 2-Phase Synchronous Step-Down DC/DC Controller with Diffamp |
| Pages / Page | 40 / 4 — elecTrical characTerisTics. The. denotes the specifications which apply … |
| File Format / Size | PDF / 840 Kb |
| Document Language | English |
elecTrical characTerisTics. The. denotes the specifications which apply over the full operating
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LTC3856
elecTrical characTerisTics The
l
denotes the specifications which apply over the full 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
TG Transition Time (Note 6) TG1,2 tr Rise Time CLOAD = 3300pF 25 ns TG1,2 tf Fall Time CLOAD = 3300pF 25 ns BG Transition Time (Note 6) BG1,2 tr Rise Time CLOAD = 3300pF 25 ns BG1,2 tf Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 30 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 30 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 90 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN ≤ 38V 4.8 5.0 5.2 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 = 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 210 250 290 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 700 770 850 kHz RMODE MODE Input Resistance 250 kΩ IFREQ Frequency Setting Output Current 9 10 11 µA CLKOUT Phase (Relative to Controller 1) PHASMD = GND; Non Stage Shedding Mode 60 Deg PHASMD = FLOAT; Non Stage Shedding Mode 90 Deg PHASMD = INTVCC; Non Stage Shedding Mode 120 Deg Stage Shedding Mode 180 Deg CLKHIGH Clock High Output Voltage 4 5 V CLKLOW Clock Low Output Voltage 0 0.2 V
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.2 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±2 µA VPG PGOOD Trip Level, Either Controller VFB with Respect to Set Output Voltage VFB Ramping Negative –10 % VFB Ramping Positive 10 % 3856fa 4 For more information www.linear.com/LTC3856 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 Application Typical Application Related Parts
elecTrical characTerisTics The
l
denotes the specifications which apply over the full 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
TG Transition Time (Note 6) TG1,2 tr Rise Time CLOAD = 3300pF 25 ns TG1,2 tf Fall Time CLOAD = 3300pF 25 ns BG Transition Time (Note 6) BG1,2 tr Rise Time CLOAD = 3300pF 25 ns BG1,2 tf Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 30 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 30 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 90 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN ≤ 38V 4.8 5.0 5.2 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 = 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 210 250 290 kHz fHIGH Highest Frequency VFREQ ≥ 2.4V 700 770 850 kHz RMODE MODE Input Resistance 250 kΩ IFREQ Frequency Setting Output Current 9 10 11 µA CLKOUT Phase (Relative to Controller 1) PHASMD = GND; Non Stage Shedding Mode 60 Deg PHASMD = FLOAT; Non Stage Shedding Mode 90 Deg PHASMD = INTVCC; Non Stage Shedding Mode 120 Deg Stage Shedding Mode 180 Deg CLKHIGH Clock High Output Voltage 4 5 V CLKLOW Clock Low Output Voltage 0 0.2 V
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.2 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±2 µA VPG PGOOD Trip Level, Either Controller VFB with Respect to Set Output Voltage VFB Ramping Negative –10 % VFB Ramping Positive 10 % 3856fa 4 For more information www.linear.com/LTC3856 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 Application Typical Application Related Parts
