Datasheet LT8311 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | Synchronous Rectifier Controller with Opto-Coupler Driver for Forward Converters |
| Pages / Page | 48 / 6 — ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 744 Kb |
| Document Language | English |
ELECTRICAL. CHARACTERISTICS The. denotes the specifications which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LT8311
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 12V, VINTVCC = 8V, PMODE = 5V, CCG = CFG = 100pF, unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS SYNC Mode (Tie PMODE to INTVCC)
SYNC High Trip Voltage SYNC Ramp Up l 0.9 1.2 1.5 V Hysteresis –2.4 V SYNC Low Trip Voltage SYNC Ramp Down l –1.5 –1.2 –0.9 V Hysteresis 2.4 V SYNC Minimum Pulse Width SYNC = 0V to ±2V Pulse l 40 100 ns SYNC = 0V to ±6V Pulse (Note 5) 20 ns SYNC Input Current –3.5V < SYNC < 3.5V ±1 µA SYNC = ±10V (Note 6, 7) l 300 400 µA SYNC Propagation Delay To CG/FG SYNC Rising Edge (0V to 2V) to CG Rising Edge (Note 8) l 100 150 ns Outputs SYNC Rising Edge (0V to 6V) to CG Rising Edge (Notes 5, 8) 75 ns SYNC Falling Edge (0V to 2V) to FG Rising Edge (Note 8) l 100 150 ns SYNC Falling Edge (0V to 6V) to FG Rising Edge (Notes 5, 8), CCG = CFG = 3.3nF 85 ns TIMER Timeout Frequency RTIMER = 41.2k l 425 505 585 kHz RTIMER = 71.5k l 255 300 345 kHz RTIMER = 221k l 80 100 120 kHz TIMER Short-Circuit Current TIMER = 0V l 40 60 µA
Current Comparator
Current Comparator Trip Threshold CSP Ramp Up, RCSP = RCSN = 0Ω l 48 62 72 mV CSP Ramp Up, RCSP = RCSN = 1.62kΩ (Note 5) 0 mV Current Comparator Blank Time in From Rising CG Edge Until Blanking Ends (Note 5) 250 ns Preactive Mode Current Comparator Blank Time in From Rising CG Edge Until Blanking Ends 400 ns SYNC Mode CSP Current at Low CSP Voltage CSP = 0V (Note 6) l 30 38 50 µA CSP Current at High CSP Voltage CSP = 150V (Note 7) l 200 500 µA CSN Current CSN = 0V (Note 6) l 0.1 1 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature will exceed the maximum operating junction temperature may cause permanent damage to the device. Exposure to any Absolute when overtemperature is active. Continuous operating above the specified Maximum Rating condition for extended periods may affect device maximum operating junction temperature may impair device reliability. reliability and lifetime.
Note 4:
Rise and fall times of are measured between 10% and 90% points
Note 2:
The LT8311 is tested under pulsed load conditions such that of a signal edge. TJ ~ TA. The LT8311E is guaranteed to meet specifications from 0°C to
Note 5:
Guaranteed by design and/or correlation to static test. 125°C junction temperature. Specifications over the –40°C to 125°C
Note 6:
Current flows out of pin. operating junction temperature are assured by design, characterization and correlation with statistical process controls. The LT8311I is guaranteed
Note 7:
Current flows into pin. over the –40°C to 125°C operating junction temperature range. The
Note 8:
Propagation delay is measured between 50% point of the two LT8311H is guaranteed over the –40°C to 150°C operating junction signal edges of interest. temperature range, and the LT8311MP is guaranteed over the –55°C to
Note 9:
SS charge current refers to current flowing out of SS pin after 150°C operating junction temperature range. High junction temperatures certain conditions satisfied upon LT8311 wake-up (see the flowchart for degrade operating lifetimes; operating lifetime is derated for junction Opto-Control Operation at Start-Up in Figure 9). temperatures greater than 125°C.
Note 10:
CSW is a square waveform (duty cycle = 50%) with VHIGH = 7V
Note 3:
The LT8311 includes overtemperature protection that is intended and VLOW = –0.7V. to protect the device during momentary overload conditions. Junction 8311f 6 For more information www.linear.com/LT8311 Document Outline Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation FUNDAMENTALS OF FORWARD CONVERTER OPERATION IN CCM LT8311 SYNCHRONOUS CONTROL SCHEMES PREACTIVE MODE SYNCHRONOUS CONTROL SYNC MODE SYNCHRONOUS CONTROL OPTO-COUPLER CONTROL Applications Information VIN BIAS SUPPLY INTVCC BIAS SUPPLY LT8311 OPTO CONTROL FUNDAMENTALS LT8311 SYNCHRONOUS CONTROL FUNDAMENTALS PREACTIVE MODE SYNCHRONOUS CONTROL SYNC MODE SYNCHRONOUS CONTROL Typical Applications Package Description 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 = 12V, VINTVCC = 8V, PMODE = 5V, CCG = CFG = 100pF, unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS SYNC Mode (Tie PMODE to INTVCC)
SYNC High Trip Voltage SYNC Ramp Up l 0.9 1.2 1.5 V Hysteresis –2.4 V SYNC Low Trip Voltage SYNC Ramp Down l –1.5 –1.2 –0.9 V Hysteresis 2.4 V SYNC Minimum Pulse Width SYNC = 0V to ±2V Pulse l 40 100 ns SYNC = 0V to ±6V Pulse (Note 5) 20 ns SYNC Input Current –3.5V < SYNC < 3.5V ±1 µA SYNC = ±10V (Note 6, 7) l 300 400 µA SYNC Propagation Delay To CG/FG SYNC Rising Edge (0V to 2V) to CG Rising Edge (Note 8) l 100 150 ns Outputs SYNC Rising Edge (0V to 6V) to CG Rising Edge (Notes 5, 8) 75 ns SYNC Falling Edge (0V to 2V) to FG Rising Edge (Note 8) l 100 150 ns SYNC Falling Edge (0V to 6V) to FG Rising Edge (Notes 5, 8), CCG = CFG = 3.3nF 85 ns TIMER Timeout Frequency RTIMER = 41.2k l 425 505 585 kHz RTIMER = 71.5k l 255 300 345 kHz RTIMER = 221k l 80 100 120 kHz TIMER Short-Circuit Current TIMER = 0V l 40 60 µA
Current Comparator
Current Comparator Trip Threshold CSP Ramp Up, RCSP = RCSN = 0Ω l 48 62 72 mV CSP Ramp Up, RCSP = RCSN = 1.62kΩ (Note 5) 0 mV Current Comparator Blank Time in From Rising CG Edge Until Blanking Ends (Note 5) 250 ns Preactive Mode Current Comparator Blank Time in From Rising CG Edge Until Blanking Ends 400 ns SYNC Mode CSP Current at Low CSP Voltage CSP = 0V (Note 6) l 30 38 50 µA CSP Current at High CSP Voltage CSP = 150V (Note 7) l 200 500 µA CSN Current CSN = 0V (Note 6) l 0.1 1 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature will exceed the maximum operating junction temperature may cause permanent damage to the device. Exposure to any Absolute when overtemperature is active. Continuous operating above the specified Maximum Rating condition for extended periods may affect device maximum operating junction temperature may impair device reliability. reliability and lifetime.
Note 4:
Rise and fall times of are measured between 10% and 90% points
Note 2:
The LT8311 is tested under pulsed load conditions such that of a signal edge. TJ ~ TA. The LT8311E is guaranteed to meet specifications from 0°C to
Note 5:
Guaranteed by design and/or correlation to static test. 125°C junction temperature. Specifications over the –40°C to 125°C
Note 6:
Current flows out of pin. operating junction temperature are assured by design, characterization and correlation with statistical process controls. The LT8311I is guaranteed
Note 7:
Current flows into pin. over the –40°C to 125°C operating junction temperature range. The
Note 8:
Propagation delay is measured between 50% point of the two LT8311H is guaranteed over the –40°C to 150°C operating junction signal edges of interest. temperature range, and the LT8311MP is guaranteed over the –55°C to
Note 9:
SS charge current refers to current flowing out of SS pin after 150°C operating junction temperature range. High junction temperatures certain conditions satisfied upon LT8311 wake-up (see the flowchart for degrade operating lifetimes; operating lifetime is derated for junction Opto-Control Operation at Start-Up in Figure 9). temperatures greater than 125°C.
Note 10:
CSW is a square waveform (duty cycle = 50%) with VHIGH = 7V
Note 3:
The LT8311 includes overtemperature protection that is intended and VLOW = –0.7V. to protect the device during momentary overload conditions. Junction 8311f 6 For more information www.linear.com/LT8311 Document Outline Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation FUNDAMENTALS OF FORWARD CONVERTER OPERATION IN CCM LT8311 SYNCHRONOUS CONTROL SCHEMES PREACTIVE MODE SYNCHRONOUS CONTROL SYNC MODE SYNCHRONOUS CONTROL OPTO-COUPLER CONTROL Applications Information VIN BIAS SUPPLY INTVCC BIAS SUPPLY LT8311 OPTO CONTROL FUNDAMENTALS LT8311 SYNCHRONOUS CONTROL FUNDAMENTALS PREACTIVE MODE SYNCHRONOUS CONTROL SYNC MODE SYNCHRONOUS CONTROL Typical Applications Package Description Typical Application Related Parts
