lm5039mhx National Semiconductor Corporation, lm5039mhx Datasheet
lm5039mhx
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... Packages • TSSOP-20EP (Thermally enhanced) • LLP-24 (4mm x 5mm) [Coming soon] Simplified Application Diagram © 2010 National Semiconductor Corporation LM5039 Features ■ 105V / 2A Half-Bridge Gate Drivers ■ Synchronous Rectifier Control Outputs with Programmable Delays ■ ...
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Connection Diagrams www.national.com Top View 20-Lead TSSOP EP Top View LLP-24 Package [Coming soon] 2 30100502 30100503 ...
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... Ordering Information Order Number Package Type LM5039MH TSSOP-20EP LM5039MHX TSSOP-20EP Pin Descriptions TSSOP LLP Pin Name Pin 1 23 RAMP Modulator ramp signal 2 24 UVLO Line Under-Voltage Lockout 3 2 ACL Average Current Limit 4 3 COMP Input to the Pulse Width Modulator An external opto-coupler connected to the COMP pin sources ...
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TSSOP LLP Pin Name Pin 9 8 DLY Timing programming pin for the LO and HO to SR1 and SR2 outputs RES Restart Timer Boost voltage for the HO driver Switch node ...
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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, SS, ...
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Symbol Parameter Soft-Start (SS Pin) I Charging current in normal SS operation Charging current during a hiccup mode restart Oscillator (RT Pin) F Frequency 1(at HO, half oscillator SW1 frequency) F Frequency 2 (at HO, half oscillator SW2 frequency) F ...
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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 30100505 30100507 Soft-Start & Stop Current vs Temperature 30100509 VCC VCC 30100506 Oscillator Frequency vs ...
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Effective Comp Input Impedance 30100511 SR "T1" Parameter vs Temperature 30100513 Deadtime DLY SR "T2" Parameter vs Temperature 9 30100512 30100514 www.national.com ...
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Block Diagram www.national.com FIGURE 1. 10 30100504 ...
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Functional Description The LM5039 PWM controller contains all of the features nec- essary to implement half-bridge voltage-mode controlled power converters. The LM5039 provides two gate driver out- puts to directly drive the primary side power MOSFETs and two signal level ...
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Current Limit The LM5039 utilizes two high-speed comparators to imple- ment a current limiting in an overload condition: A higher threshold (600mV) comparator is used to implement a fast peak cycle-by-cycle current limit to provide instantaneous protection to the power ...
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Frequency Foldback Ideally, a power converter will have the characteristics of a constant current source while operating in current limit. In re- ality, the current limit level tends to increase as the output voltage decreases hard-short condition, avoiding ...
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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 LM5039, the SS pin capacitor is discharged by an internal MOSFET. ...
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If load transient response is slowed by the 10% margin, the R value can be increased. The system signal-to-noise will FF be slightly decreased by increasing R FF Oscillator, Sync ...
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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 LM5039. 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 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 while HO is driving the high-side MOSFET will ...
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PROGRAMMABLE DELAY (DLY) The R resistor programs the delays between the SR1 and DLY SR2 signals and the HO and LO driver outputs. shows the relationship between these outputs. The DLY pin is nominally set at 2.5V and the current ...
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AVERAGE CURRENT LIMIT The average current control circuitry is activated by connect- ing an appropriate capacitor from the ACL pin to AGND overload condition, the current sourced by the ACL capacitor pulls down the input of the PWM ...
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Printed Circuit Board Layout The LM5039 Current Sense and PWM comparators are very fast, and respond to short duration noise pulses. The compo- nents at the CS, COMP, SS, ACL, UVLO, DLY and the RT pins should be as physically ...
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Physical Dimensions inches (millimeters) unless otherwise noted Molded TSSOP-20 NS Package Number MXA20A 24-Lead LLP Package NS Package Number SQA24B 23 www.national.com ...
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