LM5088MH-2/NOPB National Semiconductor, LM5088MH-2/NOPB Datasheet
LM5088MH-2/NOPB
Specifications of LM5088MH-2/NOPB
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LM5088MH-2/NOPB Summary of contents
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... The device is available in a thermally enhanced TSSOP-16EP pin package. Simplified Application Schematic © 2011 National Semiconductor Corporation LM5088/LM5088Q Features ■ LM5088Q is an Automotive Grade product that is AEC- Q100 grade 1 qualified (-40° ...
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... TSSOP-16EP, Dithering LM5088QMHX-1 TSSOP-16EP, Dithering LM5088MH-2 TSSOP-16EP, Restart LM5088MHX-2 TSSOP-16EP, Restart LM5088QMH-2 TSSOP-16EP, Restart LM5088QMHX-2 TSSOP-16EP, Restart *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 AEC-Q100 standard. Automotive grade products are identified with the letter Q ...
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Pin Descriptions Pin(S) Name Description 1 VIN Input supply voltage 2 EN Enable input 3 SS Soft-start 4 RAMP Ramp control signal 5 RT/SYNC Internal oscillator frequency set input and synchronization input 6 GND Ground 7 COMP Output of the ...
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Pin(S) Name Description 15 BOOT Input for bootstrap capacitor An external capacitor is required between the BOOT and the SW pins to provide 16 VCC Output of the bias regulator VCC tracks VIN up to the regulation level (7.8V Typ). ...
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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, VOUT to GND BOOT to GND SW to GND VCC to GND GND BOOT to SW Electrical Characteristics junction temperature (T ) range of -40°C to +125°C. Minimum and Maximum limits are guaranteed through test, design, or statistical J correlation ...
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... Note 3: RAMP and COMP are output pins. As such they are not specified to have an external voltage applied. Note 4: Typical specifications represent the most likely parametric norm at 25°C operation. Note 5: For detailed information on soldering plastic MSOP packages refer to the Packaging Data Book available from National Semiconductor Corporation. www.national.com ...
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Typical Performance Characteristics Typical Application Circuit Efficiency VCC VCC Frequency vs R 30083940 30083942 RT 30083944 30083941 Shutdown Current 30083943 Frequency vs V VCC 30083945 www.national.com ...
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V vs Temperature FB Soft-Start vs Temperature Frequency vs Temperature www.national.com Forced-Off Time vs Temperature 30083946 Current-Limit vs Temperature 30083948 Error Amplifier Gain/Phase 30083950 8 30083947 30083949 30083951 ...
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Block Diagram FIGURE 1. Block Diagram 9 30083904 www.national.com ...
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Detailed Operation The LM5088 Wide Input Range Buck Controller features all the functions necessary to implement an efficient high voltage step-down converter using a minimum number of external components. The control method is based on peak current mode control utilizing ...
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Error Amplifier and PWM Comparator The internal high gain error amplifier generates an error signal proportional to the difference between the regulated output voltage and an internal precision voltage reference (1.205V). The output of the error amplifier is connected to ...
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The sample & hold DC level illustrated in Figure 3 is derived from a measurement of the re-circulating (or free-wheeling) diode current. The diode current flows through the current sense resistor connected between the CS and CSG pins. The voltage ...
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Where 1/f and T is the forced off-time (280 OSC SW OFF (max) ns typical, 365 ns maximum); f and T SW frequency and oscillator period, respectively. From the above equation, it can be seen that for a ...
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FIGURE 6. Conducted Emissions Measured at the Input of a LM5088 Based Buck Converter Figure 6 shows the conducted emissions on the LM5088 evaluation board input power line. It can be seen from the above picture that, the peak emissions ...
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FET when it is turned ON, if the V exceeds 1.5V, the comparator turns off the buck DS FET immediately. This feature will help protect the buck FET in catastrophic conditions such ...
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Soft-Start The soft-start (SS) feature forces the output to rise linearly until it reaches the steady-state operating voltage set by the feedback resistors. The LM5088 will regulate the FB pin to the SS pin voltage or the internal 1.205V reference, ...
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The maximum ripple current occurs at the maximum input voltage. Typically selected between 20% and 40 the full load current. Higher ripple current will result in a small- er inductor. However, it places more burden on ...
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FIGURE 10. Additional Slope Compensation for VOUT > 5V OUTPUT CAPACITORS The output capacitors smooth the inductor current ripple and provide a source of charge for load transient conditions. The output capacitor selection is primarily dictated by the following specifications: ...
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OUTPUT VOLTAGE DIVIDER R and R set the output voltage level, the ratio of these FB1 FB2 resistors can be calculated from: 1.62 kΩ was chosen for R in this design which results in a FB1 R value of 5.11 ...
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ERROR AMPLIFIER COMPENSATION and C configure the error amplifier gain COMP COMP HF characteristics to accomplish a stable voltage loop gain. One advantage of current mode control is the ability of to close the loop with only ...
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PCB BOARD LAYOUT AND THERMAL CONSIDERATIONS In a buck regulator there are two loops where currents are switched very fast. The first loop starts from the input capac- itors, through the buck MOSFET, to the inductor then out to the ...
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Bill of Materials for LM5088-1 and LM5088-2 Evaluation Boards Part Value C1,C2,C3,C4, 2.2µF C5 C6,C19 0.1µF C7 1µF C8,C11 100pF C9 270pF C13 0.1µF C10 0.022µF C12 0.015µF C15 470µF 0.327x0.327x0. C17,C18 47µF C20 1000pF C16 NU 0.327x0.327x0. C21 NU ...
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Part Value Package R10 NU R0603 J1,J2,J3,J4 Terminal_Turret TP1,TP2 Slotted test point U1 PWM IC TSSOP16_EP Manufacturer Manufacturer Part Number Description NU NU Keystone 1509 Keystone 1040 National LM5088-1/LM5088 Terminal, Turret Terminal test point slotted ECM Buck Controller ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 16-Lead TSSOP-EP Package NS Package Number MXA16A 26 ...
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Notes 27 www.national.com ...
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