Datasheet LT8310 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | 100VIN Forward Converter Controller |
| Pages / Page | 36 / 10 — pin FuncTions. SENSE (Pin 13):. VIN (Pin 18):. GATE (Pin 14):. INTVCC … |
| File Format / Size | PDF / 430 Kb |
| Document Language | English |
pin FuncTions. SENSE (Pin 13):. VIN (Pin 18):. GATE (Pin 14):. INTVCC (Pin 15):. NC (Pin 20):. GND (Exposed Pad Pin 21):
Model Line for this Datasheet
Text Version of Document
LT8310
pin FuncTions SENSE (Pin 13):
Switch Current Sense Input. Positive Resistor value accuracy contributes directly to the output input of the low side current sense to the control loops voltage accuracy, choose appropriate tolerance. In current and the overcurrent comparator. Kelvin-connect this pin to mode applications, feedback sets VOUT, therefore program the sense resistor at the source of the N-channel MOSFET RSET to set a maximum duty cycle guardrail that constrains switch. Exceeding 125mV at this pin triggers an overcur- the volt-seconds of flux in the transformer during transients. rent fault, and sends the system into fast shutdown, slow This pin must be connected to INTVCC by a resistor. wake-up, and soft-start.
VIN (Pin 18):
Supply Input and System Input Voltage
GATE (Pin 14):
Switch Control Output. Low side switch Sense. Input supply for the part; operational from 6V to drive (GND to INTVCC) for external N-channel MOSFET. The 100V. Accurate duty cycle requires accurate sensing of maximum duty cycle is limited to 78% (typ) because reso- the VIN voltage, so keep the connection to the transformer nant reset forward converters require time for transformer primary short to minimize resistive voltage drops. Bypass flux to reset. Actively pulled to GND during shutdown. to GND with 1µF.
INTVCC (Pin 15):
Regulated Supply Output. A 10V LDO
NC (Pin 20):
No Internal Connection. Connect to VIN. supply generated from VIN and capable of supplying the
GND (Exposed Pad Pin 21):
Ground. This pin also senses GATE pin. Must be bypassed with a 4.7µF capacitor or the negative terminal of the current sense resistor. Solder higher. The regulator voltage can be externally driven up the exposed pad directly to the ground plane. to 17V, as long as VIN ≥ VINTVCC, to reduce internal power dissipation from VIN or to accommodate more than 10V gate drive for high voltage N-channel MOSFETs.
RDVIN (Pin 16):
Duty Cycle Control Input. This pin sinks a precise 20µA in normal operation, but less during soft- start, when the duty cycle is folded back. Connect a resistor RSET between the INTVCC and RDVIN pins to program the desired (no opto) application output voltage: ⎛ VOUT ⎞ ⎛ ⎞ ⎜ ⎟ R NP ⎝ 12 ⎠ SET = ⎜ ⎟ • ⎝N 20µA S ⎠ 8310f 10 For more information www.linear.com/LT8310 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagrams Operation Applications Information Typical Applications Package Description Typical Application Related Parts
pin FuncTions SENSE (Pin 13):
Switch Current Sense Input. Positive Resistor value accuracy contributes directly to the output input of the low side current sense to the control loops voltage accuracy, choose appropriate tolerance. In current and the overcurrent comparator. Kelvin-connect this pin to mode applications, feedback sets VOUT, therefore program the sense resistor at the source of the N-channel MOSFET RSET to set a maximum duty cycle guardrail that constrains switch. Exceeding 125mV at this pin triggers an overcur- the volt-seconds of flux in the transformer during transients. rent fault, and sends the system into fast shutdown, slow This pin must be connected to INTVCC by a resistor. wake-up, and soft-start.
VIN (Pin 18):
Supply Input and System Input Voltage
GATE (Pin 14):
Switch Control Output. Low side switch Sense. Input supply for the part; operational from 6V to drive (GND to INTVCC) for external N-channel MOSFET. The 100V. Accurate duty cycle requires accurate sensing of maximum duty cycle is limited to 78% (typ) because reso- the VIN voltage, so keep the connection to the transformer nant reset forward converters require time for transformer primary short to minimize resistive voltage drops. Bypass flux to reset. Actively pulled to GND during shutdown. to GND with 1µF.
INTVCC (Pin 15):
Regulated Supply Output. A 10V LDO
NC (Pin 20):
No Internal Connection. Connect to VIN. supply generated from VIN and capable of supplying the
GND (Exposed Pad Pin 21):
Ground. This pin also senses GATE pin. Must be bypassed with a 4.7µF capacitor or the negative terminal of the current sense resistor. Solder higher. The regulator voltage can be externally driven up the exposed pad directly to the ground plane. to 17V, as long as VIN ≥ VINTVCC, to reduce internal power dissipation from VIN or to accommodate more than 10V gate drive for high voltage N-channel MOSFETs.
RDVIN (Pin 16):
Duty Cycle Control Input. This pin sinks a precise 20µA in normal operation, but less during soft- start, when the duty cycle is folded back. Connect a resistor RSET between the INTVCC and RDVIN pins to program the desired (no opto) application output voltage: ⎛ VOUT ⎞ ⎛ ⎞ ⎜ ⎟ R NP ⎝ 12 ⎠ SET = ⎜ ⎟ • ⎝N 20µA S ⎠ 8310f 10 For more information www.linear.com/LT8310 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagrams Operation Applications Information Typical Applications Package Description Typical Application Related Parts
