LM5117PMH/NOPB National Semiconductor, LM5117PMH/NOPB Datasheet
LM5117PMH/NOPB
Specifications of LM5117PMH/NOPB
Related parts for LM5117PMH/NOPB
LM5117PMH/NOPB Summary of contents
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... Additional features include thermal shutdown, fre- quency synchronization, hiccup mode current limit and adjustable line under-voltage lockout. Typical Application © 2011 National Semiconductor Corporation LM5117 Features ■ Emulated peak current mode control ■ ...
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Connection Diagrams Ordering Information Order Number Package Type LM5117PMH TSSOP-20EP LM5117PMHE TSSOP-20EP LM5117PMHX TSSOP-20EP LM5117PSQ LLP-24 LM5117PSQE LLP-24 LM5117PSQX LLP-24 www.national.com Top View 20-Lead TSSOP EP 30143202 Top View LLP-24 (4mmx4mm) NSC Package Supplied As Drawing MXA20A 73 Units Per ...
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Pin Descriptions TSSOP LLP Name Description Pin Pin 1 24 UVLO Under-voltage lockout programming pin. If the UVLO pin voltage is below 0.4V, the regulator is in the shutdown mode with all functions disabled. If the UVLO pin voltage is ...
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TSSOP LLP Name Description Pin Pin High-side NMOS gate drive output. Connect to the gate of the high-side NMOS transistor through a short, low inductance path High-side driver supply for the bootstrap gate drive. ...
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Absolute Maximum Ratings VIN to AGND SW to AGND VCC to AGND (Note AGND FB, DEMB, RES, VCCDIS, UVLO to AGND CM, COMP to AGND(Note 3) Electrical Characteristics junction temperature range ...
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Symbol Parameter t Minimum HO On-time ON(MIN) COMP to PWM comparator offset Oscillator f Frequency 1 SW1 f Frequency 2 SW2 RT Output Voltage RT Sync Positive Threshold Sync Pulse Width Current Limit V Cycle-by-cycle Sense Voltage CS(TH) Threshold CS ...
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Symbol Parameter θ Junction to Case JC θ Junction to Ambient JA θ Junction to Case JC Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of ...
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Typical Performance Characteristics HO Peak Driver Current vs Output Voltage Driver Dead Time vs V Forced HO Off-time vs Temperature www.national.com LO Peak Driver Current vs Output Voltage 30143203 Driver Dead Time vs Temperature VCC 30143205 30143207 8 30143204 30143206 ...
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VCC VCC 30143209 V vs Temperature CS(TH) 30143270 V vs Temperature VCC 30143273 VCC VIN V vs Temperature REF Error Amp Gain and Phase vs Frequency 9 30143269 30143271 301432162 www.national.com ...
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OUT www.national.com V 30143272 CSG-CS 30143278 ...
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Block Diagram and Typical Application Circuit FIGURE 1. Block Diagram and Typical Application Circuit 11 30143210 www.national.com ...
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Functional Description The LM5117 high voltage switching controller features all of the functions necessary to implement an efficient high voltage buck regulator that operates over a very wide input voltage range. This easy to use controller integrates high-side and low-side ...
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For 14.5V <V , the external supply voltage can be regulat- OUT ed by using a series Zener diode from the output to VCC. FIGURE 5. External VCC Supply for 14.5V <V In high input voltage applications, extra care should ...
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Ramp Generator and Emulated Current Sense The ramp signal used in the pulse width modulator for tradi- tional current mode control is typically derived directly from the high-side switch current. This switch current corresponds to the positive slope portion of ...
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and C configure the error amplifier gain and COMP COMP HF phase characteristics to achieve a stable voltage loop gain. This network creates a pole for phase boost, and a high ...
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FIGURE 10. Inductor Current During an output short condition, the worst case peak inductor current is limited to: Where t is the minimum HO on-time. ON(MIN) If the saturation current of the inductor is less than I peak inductor current ...
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HO and LO Drivers The LM5117 contains high current NMOS drivers and an as- sociated high-side level shifter to drive the external high-side NMOS device. This high-side gate driver works in conjunction with an external diode D , and bootstrap ...
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Application Information FEEDBACK COMPENSATION Open loop response of the regulator is defined as the product of modulator transfer function and feedback transfer function. When plotted scale, the open loop gain is shown as the sum of modulator ...
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SUB-HARMONIC OSCILLATION Peak current mode regulators can exhibit unstable behavior when operating above 50% duty cycle. This behavior is known as sub-harmonic oscillation and is characterized by alternating wide and narrow pulses at the SW pin. Sub-har- monic oscillation can ...
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The LM5117 has an exposed thermal pad to aid power dissi- pation. Adding several vias under the exposed pad helps conduct heat away from the IC. The junction to ambient ther- mal resistance varies with application. The most significant variables ...
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TABLE 1. LM5117 Frequency Analysis Formulas SIMPLE FORMULA MODULATOR TRANSFER FUNCTION Modulator DC Gain ESR Zero ESR Pole Not considered Dominant Load Pole Sampled Gain Not considered Inductor Pole Quality Factor Not considered Sub-harmonic Not considered Double Pole K Factor ...
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SIMPLE FORMULA Cross Over Frequency (Open Loop Bandwidth) Maximum Cross Over Frequency * Comprehensive Equation includes an inductor pole and a gain peaking at f that a ceramic capacitor C (No ESR) is connected in parallel with C OUT2 www.national.com ...
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Design Example OPERATING CONDITIONS • Output Voltage • Full Load Current • Minimum Input Voltage • Maximum Input Voltage • Switching Frequency • Diode Emulation • External VCC Supply TIMING RESISTOR R T Generally, higher frequency applications are smaller but ...
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The standard value of 165 kΩ was selected for R UVLO DIVIDER AND C UV2 UV1 The desired startup voltage and the hysteresis are set by the voltage divider R and R . Capacitor C UV1 UV2 ...
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ESR was selected as the main output capacitor. The fundamental component of the output ripple voltage with max- imum ESR is approximated as: Additional low ERS / ESL ceramic capacitors can be ...
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STEP2: Determine required R COMP Knowing calculated as follows: CROSS COMP The standard value of 27.4kΩ was selected for R STEP3: Determine C to cancel load pole COMP Knowing calculated as follows: ...
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Application Circuit FIGURE 19. 12V, 9A Typical Application Schematic 30143221 27 www.national.com ...
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Example of Constant Current Regulator The LM5117 can be configured as a constant current regula- tor by using the current monitor feature (CM) as the feedback input. A voltage divider at the VCCDIS pin from VOUT to AGND can be ...
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The LM5117 also can be configured as a constant voltage and constant current regulator, known as CV+CC regulator. In this configuration, there is much less variation in the current limiting as compared to peak cycle-by-cycle current limiting of the inductor ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 20 Pin TSSOP with Exposed Pad NS Package Number MXA20A 24 Pin LLP NS Package Number SQA24A 30 ...
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Notes 31 www.national.com ...
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