ml4894 Microsemi Corporation, ml4894 Datasheet
ml4894
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ml4894 Summary of contents
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... GENERAL DESCRIPTION The ML4894 synchronous buck controller has been designed to provide high efficiency DC/DC conversion for portable products. The ML4894 can deliver a fixed 5V output from input voltages of 5.9V to 15V. The ML4894 drives external P- and N-channel MOSFETs in a synchronous buck topology, allowing an overall ...
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... Voltage feedback pin for regulating FB the 5V output 3 I Current sense input SENSE SHDN 4 a logic low on this pin shuts down the regulator and all internal bias circuitry for minimum power consumption 2 ML4894 8-Pin SOIC (S08) V REG DRV I SENSE DRV ...
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... Operating Temperature Range (Note 1) A CONDITIONS T = 25°C A 5.9V < V < 15V IN Line, Temp 5.9V SENSE FB 5.9V < V < 15V 1000 pF, GND SHDN = 0V SHDN = 5V ML4894 ) .................................... 160°C/W JA MIN TYP MAX UNITS 3.29 3.33 3.37 V 1.7 4 mV/V 3.24 3.42 V 1.0 V 3.0 V 100 4.85 5 5.15 V -60 ...
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... ML4894 FUNCTIONAL DESCRIPTION The ML4894 converts a 5.9V to 15V input to a fixed 5V output using a unique current mode PFM synchronous buck control architecture. The output current is set by external components, and can exceed 2A. Even at light loads, the PFM architecture maintains high conversion efficiencies over a wide range of input voltages ...
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... ON OSCILLATOR ONE SHOT S Q SYNCHRONOUS R Q COMPARATOR CURRENT COMPARATOR TRANSCONDUCTANCE AMPLIFIER Figure 1. ML4894 Functional Block Diagram 7 (V) Figure 2. ON-Time vs. Input Voltage P DRV 7 SHOOT-THRU PROTECTION N DRV 6 RECTIFIER - -7mV I SENSE + 2. Figure 3 ...
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... ML4894 (ONE SHOT) INDUCTOR CURRENT ( Figure 4. One Shot and Synchronous Rectifier Timing DESIGN CONSIDERATIONS A typical design can be implemented by using the following design procedure. Note that this procedure is not intended to give final values, but to give a good starting point, and provide the relationships necessary to make trade-off decisions ...
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... ON resistance - gate charge product provides a good figure of merit by which to compare various MOSFETs, the lower the figure the better. The internal gate drivers of the ML4894 can drive over 100nC of total gate charge, but 60nC to 70nC is a more practical limit to ensure good switching times. ...
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... In high current applications it may necessary to add a small 0.1 F ceramic capacitor to bypass V ML4894. 8 OUTPUT CAPACITOR SELECTION The output capacitors determine the loop stability and the output ripple voltage. Use only low ESR capacitors ...
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... SENSE located as close to the lead of the resistor as possible. The trace length from the sense resistor to the ML4894 should be kept as short as possible and away from switching components and their traces. 2. The trace lengths from the buck regulator’s input ...
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... ORDERING INFORMATION PART NUMBER ML4894ES © Micro Linear 1996 is a registered trademark of Micro Linear Corporation. Products described herein may be covered by one or more of the following patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470. Other patents are pending Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design ...