LM5035ASQX/NOPB National Semiconductor, LM5035ASQX/NOPB Datasheet
LM5035ASQX/NOPB
Specifications of LM5035ASQX/NOPB
Related parts for LM5035ASQX/NOPB
LM5035ASQX/NOPB Summary of contents
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... The oscillator can also be synchronized to an external clock. A current sense input and a programmable timer provide cycle-by-cycle cur- rent limit and adjustable hiccup mode overload protection. Simplified Application Diagram © 2008 National Semiconductor Corporation Features ■ 105V / 2A Half-Bridge Gate Drivers ■ ...
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Connection Diagrams www.national.com Top View 20-Lead TSSOP EP Top View 20177503 LLP-24 Package 2 20177502 ...
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Ordering Information Order Number Package Type LM5035MH TSSOP-20EP LM5035MHX TSSOP-20EP LM5035SQ LLP-24 LM5035SQX LLP-24 Pin Descriptions TSSOP LLP PIN Name PIN 1 23 RAMP Modulator ramp signal 2 24 UVLO Line Under-Voltage Lockout 3 2 OVP Line Over-Voltage Protection 4 ...
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TSSOP LLP PIN Name PIN Boost voltage for the HO driver Switch node High side gate drive output Low side gate drive output PGND Power Ground ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN to GND HS to GND HB to GND VCC to GND CS, RT, DLY to GND COMP Input Current Electrical Characteristics apply over full Operating Junction Temperature range. V 27.4kΩ ...
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Symbol Parameter Soft-Start (SS Pin) I Charging current in normal SS operation Charging current during a hiccup mode restart Soft-stop Current Sink Oscillator (RT Pin) F Frequency 1 (at HO, half oscillator SW1 frequency) F Frequency 2 (at HO, half ...
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Symbol Parameter Thermal Shutdown T Shutdown temperature SD Hysteresis Thermal Resistance θ Junction to ambient, 0 LFPM Air JA Flow θ Junction to Case (EP)Thermal JC resistance θ Junction to ambient, 0 LFM Air Flow LLP- ...
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Typical Performance Characteristics V and V VCC REF REF REF Oscillator Frequency vs Temperature www.national.com vs V VIN 20177505 20177507 Soft-Start & Stop Current vs Temperature 20177509 VCC VCC 20177506 Frequency vs RT ...
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Effective Comp Input Impedance 20177511 SR "T1" Parameter vs Temperature 20177513 R vs Deadtime DLY SR "T2" Parameter vs Temperature 9 20177512 20177514 www.national.com ...
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Block Diagram www.national.com FIGURE 1. 10 20177504 ...
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Functional Description The LM5035 PWM controller contains all of the features nec- essary to implement half-bridge voltage-mode controlled power converters. The LM5035 provides two gate driver out- puts to directly drive the primary side power MOSFETs and two signal level ...
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Cycle-by-Cycle Current Limit The CS pin is driven by a signal representative of the trans- former primary current. If the voltage sensed at CS pin ex- ceeds 0.25V, the current sense comparator terminates the output driver pulse. ...
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FIGURE 2. Current Limit Restart Circuit FIGURE 3. Current Limit Restart Timing 13 20177515 20177516 www.national.com ...
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Soft-Start The soft-start circuit allows the regulator to gradually reach a steady state operating point, thereby reducing start-up stress- es and current surges. When bias is supplied to the LM5035, the SS pin capacitor is discharged by an internal MOSFET. ...
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VIN while the threshold of the clamp fixed voltage (2.5V). An example will illustrate the use of the Volt • Second Clamp comparator to achieve a 50% duty cycle limit at 200kHz ...
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Synchronous Rectifier Control Outputs (SR1 & SR2) Synchronous rectification (SR) of the transformer secondary provides higher efficiency, especially for low output voltage converters. The reduction of rectifier forward voltage drop (0.5V - 1.5V) to 10mV - 200mV V DS significantly ...
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Applications Information The following information is intended to provide guidelines for the power supply designer using the LM5035. VIN The voltage applied to the VIN pin, which may be the same as the system voltage applied to the power transformer’s ...
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FIGURE 8. Current Sense Using Current Sense Transformer FIGURE 9. Current Sense Using Current Sense Resistor (R1) If the current sense resistor method is used, the over-current condition will only be sensed while LO is driving the low-side MOSFET. Over-current ...
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MOSFET. The capacitor should be large enough to supply the MOSFET gate charge (Qg) without dis- charging to the point where the drop in gate voltage affects the MOSFET value ten to twenty ...
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The impedance seen looking into the resistor divider from the UVLO and OVP pins determines the hysteresis level. UVLO and OVP enable and disable thresholds are calculated using www.national.com FIGURE 10. Basic UVLO Configuration FIGURE 11. Basic Over-Voltage Protection FIGURE ...
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Outputs disabled due to VIN falling below UVLO threshold Outputs enabled due to VIN rising above UVLO threshold Outputs disabled due to VIN rising above OVP threshold Outputs enabled due to VIN falling below OVP threshold The typical operating ranges ...
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Once the controller has switched to standby mode, the out- puts no longer switch but the VCC and REF regulators con- tinue functioning and supply bias to the external circuitry. VCC Figure 15 shows an application of the OVP comparator ...
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In the case of continuous cycle-by-cycle current limit detec- tion at the CS pin, the time required for C hiccup mode threshold is: For example 0.01µF the time t1 is approximately RES 1.14 ms. The cool down ...
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T1 provides power to the LM5035 VCC pin when the output is in regulation. The input voltage ≊ UVLO thresholds are 34V for increasing V for decreasing V . The circuit can be shut down by driving ...
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25 www.national.com ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted Molded TSSOP-20 NS Package Number MXA20A 24-Lead LLP Package NS Package Number SQA24B 26 ...
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Notes 27 www.national.com ...
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