Datasheet LT8709 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Negative Input Synchronous Multi-Topology DC/DC Controller |
| Pages / Page | 48 / 5 — ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 802 Kb |
| Document Language | English |
ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply over the full operating
Model Line for this Datasheet
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LT8709
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications for each channel are at TA = 25°C. VGND – V–VIN = 12V, VEN/FBIN – V–VIN = 12V, VBIAS – V–VIN = 12V, unless otherwise noted. Pin voltages have the following relations: FBY is relative to the GND pin, TG and INTVEE to the BIAS pin, and all other pins to the –VIN pin, unless otherwise stated. Pin currents have the following relations: positive current is denoted as current flowing into the pin; negative current is denoted as current flowing out of the pin, unless otherwise stated. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator
Switching Frequency, fOSC RT = 46.4k l 640 750 860 kHz RT = 357k l 85 100 115 kHz Switching Frequency in Foldback Compared to Normal fOSC 1/5 ratio Switching Frequency Range Free-Running or Synchronizing l 100 750 kHz SYNC High Level for Sync l 1.5 V SYNC Low Level for Sync l 0.4 V SYNC Clock Pulse Duty Cycle VSYNC = 0V to 3V 20 80 % Recommended Min SYNC Ratio fSYNC/fOSC 3/4
Gate Drivers, BG and TG
BG Rise Time CBG = 3300pF (Note 3) 24 ns BG Fall Time CBG = 3300pF (Note 3) 21 ns TG Rise Time CTG = 3300pF (Note 3) 15 ns TG Fall Time CTG = 3300pF (Note 3) 16 ns BG and TG Non-Overlap Time TG Rising to BG Rising, CBG = CTG = 3300pF (Note 3) 80 140 220 ns BG Falling to TG Falling, CBG = CTG = 3300pF (Note 3) 45 90 150 ns BG Minimum On-Time CBG = CTG = 3300pF 150 420 ns BG Minimum Off-Time CBG = CTG = 3300pF 100 480 ns TG Minimum On-Time CBG = CTG = 3300pF 0 150 ns TG Minimum Off-Time CBG = CTG = 3300pF 290 770 ns
Power Good Indicators, PG
PG Power Good Threshold for Negative Current Out of FBY Pin Rising l 71 74.9 79 µA FBY Voltage Current Out of FBY Pin Falling l 63.5 67.5 71.5 µA PG Power Good Threshold for Positive Current into FBY Pin Rising l 71.5 75.4 79.5 µA FBY Voltage Current into FBY Pin Falling l 63.5 67.5 71.5 µA PG Power Good Hysteresis for Negative 7.4 µA FBY Voltage PG Power Good Hysteresis for Positive 7.9 µA FBY Voltage PG Anti-Glitch Delay Delay from PG Threshold Trip to PG Toggle 100 µs PG Output Voltage Low 100µA into PG Pin, |IFBY| < PG Threshold l 9 50 mV PG Leakage Current VPG = 7V, |IFBY| > PG Threshold 0.01 1 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Rise and fall times are measured using 10% and 90% levels. Delay may cause permanent damage to the device. Exposure to any Absolute times are measured using 50% levels. Maximum Rating condition for extended periods may affect device
Note 4:
This IC includes overtemperature protection that is intended reliability and lifetime. to protect the device during momentary overload conditions. Junction
Note 2:
The LT8709E is guaranteed to meet performance specifications temperature will exceed 125°C when overtemperature protection is active. from 0°C to 125°C junction temperature. Specifications over the Continuous operation over the specified maximum operating junction –40°C to 125°C operating temperature range are assured by design, temperature may impair device reliability. characterization and correlation with statistical process controls. The
Note 5:
Do not apply a positive or negative voltage or current source to the LT8709I is guaranteed over the full –40°C to 125°C operating junction BG, TG, and INTVEE pins, otherwise permanent damage may occur, except temperature range. INTVEE may be connected to –VIN if BIAS is connected to INTVCC. 8709fa For more information www.linear.com/LT8709 5
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications for each channel are at TA = 25°C. VGND – V–VIN = 12V, VEN/FBIN – V–VIN = 12V, VBIAS – V–VIN = 12V, unless otherwise noted. Pin voltages have the following relations: FBY is relative to the GND pin, TG and INTVEE to the BIAS pin, and all other pins to the –VIN pin, unless otherwise stated. Pin currents have the following relations: positive current is denoted as current flowing into the pin; negative current is denoted as current flowing out of the pin, unless otherwise stated. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator
Switching Frequency, fOSC RT = 46.4k l 640 750 860 kHz RT = 357k l 85 100 115 kHz Switching Frequency in Foldback Compared to Normal fOSC 1/5 ratio Switching Frequency Range Free-Running or Synchronizing l 100 750 kHz SYNC High Level for Sync l 1.5 V SYNC Low Level for Sync l 0.4 V SYNC Clock Pulse Duty Cycle VSYNC = 0V to 3V 20 80 % Recommended Min SYNC Ratio fSYNC/fOSC 3/4
Gate Drivers, BG and TG
BG Rise Time CBG = 3300pF (Note 3) 24 ns BG Fall Time CBG = 3300pF (Note 3) 21 ns TG Rise Time CTG = 3300pF (Note 3) 15 ns TG Fall Time CTG = 3300pF (Note 3) 16 ns BG and TG Non-Overlap Time TG Rising to BG Rising, CBG = CTG = 3300pF (Note 3) 80 140 220 ns BG Falling to TG Falling, CBG = CTG = 3300pF (Note 3) 45 90 150 ns BG Minimum On-Time CBG = CTG = 3300pF 150 420 ns BG Minimum Off-Time CBG = CTG = 3300pF 100 480 ns TG Minimum On-Time CBG = CTG = 3300pF 0 150 ns TG Minimum Off-Time CBG = CTG = 3300pF 290 770 ns
Power Good Indicators, PG
PG Power Good Threshold for Negative Current Out of FBY Pin Rising l 71 74.9 79 µA FBY Voltage Current Out of FBY Pin Falling l 63.5 67.5 71.5 µA PG Power Good Threshold for Positive Current into FBY Pin Rising l 71.5 75.4 79.5 µA FBY Voltage Current into FBY Pin Falling l 63.5 67.5 71.5 µA PG Power Good Hysteresis for Negative 7.4 µA FBY Voltage PG Power Good Hysteresis for Positive 7.9 µA FBY Voltage PG Anti-Glitch Delay Delay from PG Threshold Trip to PG Toggle 100 µs PG Output Voltage Low 100µA into PG Pin, |IFBY| < PG Threshold l 9 50 mV PG Leakage Current VPG = 7V, |IFBY| > PG Threshold 0.01 1 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Rise and fall times are measured using 10% and 90% levels. Delay may cause permanent damage to the device. Exposure to any Absolute times are measured using 50% levels. Maximum Rating condition for extended periods may affect device
Note 4:
This IC includes overtemperature protection that is intended reliability and lifetime. to protect the device during momentary overload conditions. Junction
Note 2:
The LT8709E is guaranteed to meet performance specifications temperature will exceed 125°C when overtemperature protection is active. from 0°C to 125°C junction temperature. Specifications over the Continuous operation over the specified maximum operating junction –40°C to 125°C operating temperature range are assured by design, temperature may impair device reliability. characterization and correlation with statistical process controls. The
Note 5:
Do not apply a positive or negative voltage or current source to the LT8709I is guaranteed over the full –40°C to 125°C operating junction BG, TG, and INTVEE pins, otherwise permanent damage may occur, except temperature range. INTVEE may be connected to –VIN if BIAS is connected to INTVCC. 8709fa For more information www.linear.com/LT8709 5
