lm5575q0 National Semiconductor Corporation, lm5575q0 Datasheet
lm5575q0
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lm5575q0 Summary of contents
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... The LM5575Q0 guarantees robustness with cycle-by-cycle current limit, short-circuit protection, thermal shut-down, and remote shut-down. The device is available in a power enhanced TSSOP-16 package featuring an exposed die attach pad for thermal dissipation. The LM5575Q0 is sup- ported by the full suite of WEBENCH Simplified Application Schematic WEBENCH ® ...
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... Package Type LM5575Q0MH Exposed Pad TSSOP-16 MXA16A LM5575Q0MHX Exposed Pad TSSOP-16 MXA16A * Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AECQ100 standard. Automotive Grade products are identified with letter Q ...
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... This open drain output can be connected to SW pin to aid charging the bootstrap capacitor during very light load conditions or in applications where the output may be pre- charged before the LM5575Q0 is enabled. An internal pre- charge MOSFET is turned on for 250ns each cycle just prior to the on-time interval of the buck switch. ...
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Pin(s) Name 16 BST Boost input for bootstrap capacitor NA EP Exposed Pad www.national.com Description An external capacitor is required between the BST and the SW pins. A 0.022µF ceramic capacitor is recommended. The capacitor is charged from Vcc via ...
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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 GND IN BST to GND PRE to GND SW to GND (Steady State) BST ...
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Symbol Parameter RAMP GENERATOR Ramp Current 1 Ramp Current 2 PWM COMPARATOR Forced Off-time Min On-time COMP to PWM Comparator Offset ERROR AMPLIFIER Feedback Voltage FB Bias Current DC Gain COMP Sink / Source Current Unity Gain Bandwidth DIODE SENSE ...
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Soft Start Current vs Temperature 30070847 7kΩ L 30070824 Demoboard Efficiency vs I and V OUT IN 30070826 12V IN Error Amplifier Gain/Phase A = 101 ...
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Typical Application Circuit and Block Diagram www.national.com 8 ...
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... TSSOP-16 package featuring an exposed pad to aid thermal dissipation. The functional block diagram and typical application of the LM5575Q0 are shown in Figure 1. The LM5575Q0 can be applied in numerous applications to efficiently step-down a high, unregulated input voltage. The device is well suited for telecom, industrial and automotive power bus voltage ranges. ...
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... Thus, if the SYNC pins of several LM5575Q0 IC’s are connected together, the IC with the highest internal clock fre- quency will pull the connected SYNC pins low first and termi- nate the oscillator ramp cycles of the other IC’ ...
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... In applications where the input voltage may be relatively large in comparison to the output voltage, controlling small pulsewidths and duty cycles is necessary for regulation. The LM5575Q0 utilizes a unique ramp generator, which does not actually measure the buck switch current but rather recon- structs the signal. Reconstructing or emulating the inductor ...
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The sample & hold DC level illustrated in Figure 6 is derived from a measurement of the re-circulating Schottky diode an- ode current. The re-circulating diode anode should be con- nected to the IS pin. The diode current flows through ...
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... Boost Pin The LM5575Q0 integrates an N-Channel buck switch and as- sociated floating high voltage level shift / gate driver. This gate driver circuit works in conjunction with an internal diode and an external bootstrap capacitor. A 0.022µF ceramic capacitor, connected with short traces between the BST pin and SW pin, is recommended ...
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... The worst case is to assume a short circuit load condition. In this case the diode will carry the output cur- rent almost continuously. For the LM5575Q0 this current can be as high as 2.1A. Assuming a worst case 1V drop across the diode, the maximum diode power dissipation can be as high as 2 ...
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... R4 and C5. The overall loop gain is the product of the modulator gain and the error ampli- fier gain. The DC modulator gain of the LM5575Q0 is as follows: DC Gain The dominant low frequency pole of the modulator is deter- ...
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Components R4 and C5 configure the error amplifier as a type II configuration which has a pole at DC and a zero at f π (2 R4C5). The error amplifier zero cancels the modulator pole leaving a single pole response ...
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FIGURE 12. VCC Bias from VOUT for 8V < VOUT < 14V FIGURE 13. VCC Bias with Additional Winding on the Output Inductor 17 30070818 30070819 www.national.com ...
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... LFM (Linear Feet per Minute). With a 25°C ambient temperature and no airflow, the predicted 1.1, junction temperature for the LM5575Q0 will (50 x OUT 1.25) = 88°C. If the evaluation board is operated at 1.5A out- put current, 70V input voltage and high ambient temperature for a prolonged period of time the thermal shutdown protec- tion within the IC may activate ...
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Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead TSSOP Package NS Package Number MXA16A 19 www.national.com ...
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