sc1189 Semtech Corporation, sc1189 Datasheet
sc1189
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sc1189 Summary of contents
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... The SC1189 linear sections are low dropout regulators with short circuit protection, supplying 1.25V for Vtt and 2.5V for non-GTL I/O. They can be easily adjusted to sup- ply higher voltages e.g. 1.8V chipset. ...
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... SC1189 ± ...
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... SC1189 = 0 to 70° ...
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... SC1189 ...
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... CONTROLLER GATE1 2007 Semtech Corp. VCC CS- CS+ CURRENT LIMIT REF + 70mV - ERROR AMP + - - + OSCILLATOR AGND 1.25V FET REF CONTROLLER LDOV GATE2 5 SC1189 EN BSTH LEVEL SHIFT AND DH HIGH SIDE DRIVE PGNDH R SHOOT-THRU CONTROL Q S BSTL SYNCHRONOUS DL MOSFET DRIVE PGNDL LDOS2 AGND www.semtech.com ...
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... Note 1: VID[3:0] correspond to legacy VRM8.4 voltage levels for 1.3V to 1.8V 2007 Semtech Corp. ; 0mV < (CS+-CS-) < 60mV; = 0°C < SC1189 < 85° ...
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... POWER MANAGEMENT Layout Guidelines Careful attention to layout requirements are necessary for successful implementation of the SC1189 PWM control- ler. High currents switching at 200kHz are present in the application and their effect on ground plane voltage differ- entials must be understood and minimized. 1). The high power parts of the circuit should be laid out first ...
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... The Current Sense resistor and the divider across it should form as small a loop as possible, the traces run- ning back to CS+ and CS- on the SC1189 should run par- allel and close to each other. The 0.1 F capacitor should be mounted as close to the CS+ and CS- pins as possible. ...
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... FET body di- ode will be moved through the top FET as it starts to turn on. The resulting power dissipation in the top FET will be first order approximation convenient to only con- 9 SC1189 OSC ...
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... D S where R S For a full design procedure for droop and offset, see Appli- cation Note AN97-9, “Using Droop and Vout Offset for im- proved transient response”. 10 SC1189 CIT CIT CITORS CIT ORS ORS - since the RMS ripple current in the ORS ORS ...
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... POWER MANAGEMENT FOLDBACK CURRENT LIMITING The SC1189 implements a “Hard Current Limit” overcurrent protection for the switching supply output short circuit condition, this will lead to higher than nor- mal power dissipation in the bottom side FETs. If this is problematic, foldback current limiting can be easily and ...
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... POWER MANAGEMENT Theory of Operation (Linear OCP) The Linear controllers in the SC1189 have built in Overcurrent Protection (OCP). An overcurrent is assumed to have occured when the external FET is turned fully on and the output currrent is R limited, this is detected DS(ON) by the gate voltage going very high while the output volt- age is below approximately 40% of it’ ...
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... POWER MANAGEMENT Typical Characteristics Typical Efficiency (Switching section) 100% PIN Descriptions 90% 80% Vo=1.25V 70 Output Current (A) Transient Response Vo=1.75V, Io=0A to 28A 2007 Semtech Corp. 1.75V 1.50V 2.5V Linear Short circuit output response 13 SC1189 Typical Ripple, Vo=1.75V, Io=10A www.semtech.com ...
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... POWER MANAGEMENT Typical Application Circuit 2007 Semtech Corp. 14 SC1189 www.semtech.com ...
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... SC1189 ...
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... e bxN A1 bbb C A-B D PLANE A SEE DETAIL SIDE VIEW - DETERMINED AT DATUM PLANE - Semtech Corporation Power Management Products Division 16 SC1189 DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - A .093 .104 2.35 2. .004 .012 0.10 0. .081 ...