Datasheet LT8310 (Analog Devices)

LT8310 100VIN Forward Converter Controller
FeaTures DescripTion
n
Input Voltage Range: 6V to 100V
The LT®8310 is a simple-to-use resonant reset forward n
Duty Mode Control Regulates an Isolated Output
converter controller that drives the gate of a low side
without an Opto
N-channel MOSFET from an internally regulated 10V sup- n High Efficiency Synchronous Control ply. The LT8310 features duty mode control that generates n Short-Circuit (Hiccup Mode) Overcurrent Protection a stable, regulated, isolated output using a single power n Programmable OVLO and UVLO with Hysteresis transformer. With the addition of output voltage feedback, n Programmable Frequency (100kHz to 500kHz) via opto-coupler (isolated) or directly wired (nonisolated), n Synchronizable to an External Clock current mode regulation is activated, improving output n Positive or Negative Polarity Output Voltage Feedback accuracy and load response. The flexibility to choose with a Single FBX Pin transformer turns ratio makes high step-down or step-up n Programmable Soft-Start ratios possible without operating at duty cycle extremes. n Low Shutdown Current < 1µA The user can program the switching frequency from 100kHz n Available in FE20 TSSOP with HV Pin Spacing to 500kHz to optimize efficiency, performance or external component size. A synchronous output is available for
applicaTions
controlling secondary side synchronous rectification to improve efficiency. User programmable protection features n Industrial, Automotive and Military Systems include monitors on input voltage (UVLO and OVLO) and n 48V Telecommunication Isolated Power Supplies switch current (overcurrent limit). The LT8310 soft-start n Isolated and Nonisolated DC/DC Converters feature helps protect the transformer from flux saturation. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion 78 Watt Isolated Forward Converter, ±8% VOUT
47µH V V IN OUT 12V 2:1
Output Voltage Load Regulation
36V TO 72V 2.2µF 0.6A TO 6.5A 100V 1µF • • + 14.0 ×4 86.6k 100V 22µF 100µF ×8 UVLO VIN 13.5 1.74k –VOUT 13.0 OVLO 150pF NPO LT8310 1.43k 12.5 GATE (V) 12.0 INTVCC SENSE V OUT 4.7µF 0.025Ω 102k 11.5 1% RDVIN GND DFILT 11.0 V NC SYNC SOUT NC 8310 TA01a 10nF IN = 72V 10.5 V RT SS V IN = 48V C FBX V 49.9k IN = 36V 200kHz 0.47µF 10.0 –V NC 0 1 2 3 4 5 6 7 IN IOUT (A) 8310 TA01b 8310f For more information www.linear.com/LT8310 1 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