LM5116-12EVAL National Semiconductor, LM5116-12EVAL Datasheet
LM5116-12EVAL
Specifications of LM5116-12EVAL
Related parts for LM5116-12EVAL
LM5116-12EVAL Summary of contents
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... Wide Range Synchronous Buck Controller General Description The LM5116 is a synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon cur- rent mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle by cycle current limiting and ease of loop compensation ...
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... Ramp control signal. An external capacitor connected between this pin and the AGND pin sets the ramp slope used for current mode control. 6 AGND Analog ground.Connect to PGND through the exposed pad ground connection under the LM5116 external capacitor and an internal 10µA current source set the soft start time constant for the rise of the error amp reference. The SS pin is held low during VCC < ...
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... Current sense amplifier input. Connect to the bottom of the sense resistor or the source of the low-side MOSFET if R current sensing is used. DS(ON) 14 PGND Power ground. Connect to AGND through the exposed pad ground connection under the LM5116 Connect to the gate of the low-side synchronous MOSFET through a short, low inductance path. 16 VCC Locally decouple to PGND using a low ESR/ESL capacitor located as close to the controller as possible ...
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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 VCC, VCCX, UVLO to GND (Note 3) SW GND VOUT to GND CSG to GND LO to GND SS to GND FB to GND DEMB to GND Electrical Characteristics junction temperature range of -40° ...
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Symbol Parameter Soft Start SS Current Source SS Diode Emulation Ramp Disable Threshold Offset SS Output Low Voltage Error Amplifier V FB Reference Voltage REF FB Input Bias Current COMP Sink/Source Current A DC Gain OL f ...
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Symbol Parameter HO Gate Driver V HO Low-state Output Voltage OLH V HO High-state Output Voltage OHH HO Rise Time HO High-side Fall Time I Peak HO Source Current OHH I Peak HO Sink Current OLH under-voltage ...
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Typical Performance Characteristics Typical Application Circuit Efficiency Driver Dead-time vs Temperature Driver Sink Current vs VCC Driver Source Current vs VCC 30007503 HO High R 30007505 HO Low R 30007507 7 30007504 vs VCC DS(ON) 30007506 vs VCC DS(ON) 30007508 ...
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LO High R DS(ON) LO Low R DS(ON) Forced HO Off-time vs Temperature VCCX = 5V www.national.com vs VCC 30007509 vs VCC 30007511 30007513 8 EN Input Threshold vs Temperature 30007510 UVLO vs Temperature 30007512 HB DC ...
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Frequency 30007515 Frequency vs Temperature 30007517 Frequency vs Temperature 30007519 Error Amp Gain vs Frequency Error Amp Phase vs Frequency Current Limit Threshold vs Temperature 9 30007516 30007518 30007520 www.national.com ...
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VIN Operating Current vs Temperature VCC UVLO vs Temperature VCC vs ICC www.national.com VCC vs Temperature 30007521 30007523 VCCX Switch R 30007525 10 30007522 VCC vs VIN 30007524 vs VCCX DS(ON) 30007526 ...
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Block Diagram and Typical Application Circuit 11 www.national.com ...
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... VIN and GND pins are essential. Enable The LM5116 contains an enable function allowing a very low input current shutdown. If the enable pin is pulled below 0.5V, the regulator enters shutdown, drawing less than 10µA from the VIN pin ...
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... Oscillator and Sync Capability The LM5116 oscillator frequency is set by a single external resistor connected between the RT/SYNC pin and the AGND pin. The resistor should be located very close to the device and connected directly to the pins of the IC (RT/SYNC and AGND) ...
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... Adding ex- ternal resistors R sense amplifier gain A becomes: Current Limit The LM5116 contains a current limit monitoring scheme to protect the circuit from possible over-current conditions. When set correctly, the emulated current sense signal is pro- portional to the buck switch current with a scale factor deter- mined by the current limit sense resistor ...
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... The soft-start feature allows the regulator to gradually reach the initial steady state operating point, thus reducing start-up stresses and surges. The LM5116 will regulate the FB pin to the SS pin voltage or the internal 1.215V reference, whichever is lower. At the beginning of the soft-start sequence when SS = 0V, the internal 10µ ...
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... DEMB increase resulting in the gradual transition to synchronous operation. Forcing diode emulation during soft-start allows the LM5116 to start up into a pre-biased output without un- necessarily discharging the output capacitor. Full syn- chronous operation is obtained if the DEMB pin is always biased to a higher potential than the SW pin when LO is high. ...
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... If step input voltage transients are expected near m the maximum rating of the LM5116, a careful evaluation of the ringing and possible overshoot at the device VIN pin should be completed. To minimize overshoot make C The characteristic source impedance and resonant frequency ...
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The converter exhibits a negative input impedance which is lowest at the minimum input voltage: The damping factor for the input filter is given by: Where R is the input wiring resistance and ESR is the series IN resistance of ...
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... LM5116 and not in the MOSFET it- self. Further loss in the LM5116 is incurred as the gate driving current is supplied by the internal linear regulator. The gate drive current supplied by the VCC regulator is calculated as: ...
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FIGURE 11. Modulator Gain and Phase Components R and C configure the error amplifier COMP COMP as a type II configuration. The DC gain of the amplifier is 80dB which has a pole at low frequency and a zero at ...
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The regulator has an exposed thermal pad to aid power dis- sipation. Selecting MOSFETs with exposed pads will aid the power dissipation of these devices. Careful attention high temperature should be observed. Also, at 250 kHz, (ON) ...
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MODULATOR TRANSFER FUNCTION The following equations can be used to calculate the control- to-output transfer function the effective DC gain of the modulating comparator. The m duty cycle the proportional ...
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23 www.national.com ...
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... CRCW06031211F R5 R6, R7 CRCW06030R0J R8 CRCW0603103J R9 CRCW06031242F R10 CRCW0603183J R11 LRC-LRF2010-01- R010-F R12 R13 CRCW0603105J R14 U1 LM5116MHX www.national.com Type Size Capacitor, Ceramic 0805 Capacitor, Ceramic 0603 Capacitor, Ceramic 0603 Capacitor, Ceramic 0603 Capacitor, Ceramic 0603 Capacitor, Ceramic 0603 Capacitor, Ceramic 1812 Capacitor, Ceramic ...
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Physical Dimensions inches (millimeters) unless otherwise noted TSSOP-20EP Outline Drawing NS Package Number MXA20A 25 www.national.com ...
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