LTC1143L LINER [Linear Technology], LTC1143L Datasheet
LTC1143L
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LTC1143L Summary of contents
Page 1
... The operating current level for both regulators is user- programmable via an external current sense resistor. Wide input supply range allows operation from 4V to 14V (16V maximum). The LTC1143L and LTC1143L-ADJ extend operation to V low dropout regulation limited only by the R external MOSFET and resistance of the inductor and current sense resistor ...
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... LTC1143L-ADJ ABSOLUTE MAXIMUM Input Supply Voltage (Pins 5,13) ............... 16V to –0.3V Continuous Output Current (Pins 4,12) ................ 50mA Sense Voltages (Pins 16) V 12.7V .......................................... 13V to – 0. < 12.7V .............................. (V IN Shutdown Voltage (LTC1143, LTC1143L, Pins 2, 10)...........7V to – 0.3V U PACKAGE/ORDER INFORMATION TOP VIEW + – SENSE SENSE 3 SHUTDOWN 3 2 ...
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... T t Off-Time (Note 3) OFF Driver Output Transition Times r f – (Note 4 10V unless otherwise noted Feedback Voltage (LTC1143L-ADJ Regulated Output Voltage OUT LTC1143/LTC1143L 3.3V Output 5V Output Input DC Supply Current (Note LTC1143: Normal Mode ...
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... LTC1143 G02 Line Regulation OUT LOAD –10 –20 –30 – INPUT VOLTAGE (V) LTC1143 G05 Supply Current in Shutdown 20 PER LTC1143/LTC1143L 18 REGULATOR BLOCK PINS SHUTDOWN INPUT VOLTAGE (V) ...
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... Schottky diode D2 and (–) terminal of C (see Figure 9). IN5 P-DRIVE 5 (Pin 12): High Current Drive for Top P-Channel MOSFET, 5V Section. Voltage swing at this pin is from V to ground. IN5 LTC1143/LTC1143L LTC1143L-ADJ Current Sense Threshold Voltage 175 MAXIMUM THRESHOLD 150 125 100 75 50 ...
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... SENSE 3 (Pin 16): Connects to internal resistive divider which sets the output voltage for the 3.3V section. Pin 16 is also the (–) input for the current comparator on the 3.3V section. LTC1143L-ADJ + SENSE 1 (Pin 1): The (+) Input to the Section 1 Current Comparator. A built-in offset between Pins 1 and 16 in ...
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... U U FUNCTIONAL DIAGRA Only one regulator block shown. Connections shown for LT1143/LTC1143L; changes create LTC1143L-ADJ SLEEP – – V TH1 V TH2 T + OFF-TIME 14(6) CONTROL OPERATION Refer to Functional Diagram and Figure 1. The LTC1143 series consists of two individual regulator blocks, each using current mode, constant off-time archi- tectures to switch an external power MOSFET ...
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... Burst Mode operation, a built-in offset ( APPLICATIONS INFORMATION The basic LTC1143L-ADJ application circuit is shown in Figure 1. The LTC1143 and LTC1143L are similar but omit the external resistive V dividers (see Figures 10 and OUT 13). External component selection is driven by the load requirement and begins with V ...
Page 9
... Thus the inductor Note that as V When the input-to-output voltage differential drops below 1.5V for a particular section, the LTC1143 series reduces t in that section by increasing the discharge current in OFF C . This prevents audible operation prior to dropout. T LTC1143/LTC1143L LTC1143L-ADJ OUT the drop across the diode ...
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... Efficiency Considerations). (1+ the form of a normalized R Kool registered trademark of Magnetics, Inc. rating and on resistance R GS and guarantee a maximum R GS but guarantee R with V GS DS(ON) rating of the LTC1143L and IN determines the R MAX V OUT Duty Cycle ...
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... Once the ESR requirement for C rating generally far exceeds the surface mount applications multiple capacitors may OUT IN have to be parallel to meet the capacitance, ESR or RMS current handling requirements of the application. LTC1143/LTC1143L LTC1143L-ADJ OUT IN OUT I RMS MAX V IN ...
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... LTC1143/LTC1143L LTC1143L-ADJ U U APPLICATIONS INFORMATION Aluminum electrolytic and dry tantalum capacitors are both available in surface mount configurations. In the case of tantalum it is critical that the capacitors are surge tested for use in switching power supplies. An excellent choice is the AVX TPS series of surface mount tantalums, available in case heights ranging from 2mm to 4mm ...
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... losses cause the Shutdown Considerations Pins 2 and 10 on the LTC1143 and LTC1143L shut down their respective sections when pulled high. They require CMOS logic level signals with t be floated. The LTC1143L-ADJ gives up the pin-controlled shutdown function in order to gain feedback pins for programming the output voltages ...
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... LTC1143/LTC1143L LTC1143L-ADJ U U APPLICATIONS INFORMATION The LTC1143L-ADJ outputs can be turned off in one of two ways placing a power MOSFET switch in the V to the entire regulator pulling the V 1.4V, which trips comparator V and forces P-DRIVE high (see Functional Diagram). V can be pulled high with a ...
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... C close as possible to the LTC1143 series. OUT 1143 F08 4) Does the (+) plate of C P-channel MOSFET as closely as possible? This capacitor provides the AC current to the P-channel MOSFET. LTC1143/LTC1143L LTC1143L-ADJ OUT > 25mV, the built-in offset will be cancelled and , the value of the sense resistor must be lower: ...
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... F, 0.1 F) con- IN nected closely between Pin 13 (5) and GND Pin 3 (11)? This capacitor carries the MOSFET driver peak currents. 6) For the LTC1143 and LTC1143L, are the SHUT- DOWN Pins 2 and 10 actively pulled to ground during normal operation? Both SHUTDOWN pins are + + ...
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... TH2 T2 TH1 510 220pF 3300pF 3300pF P1: IR IRF7406 L1: SUMIDA CDRH125-150 P2: IR IRF7204 L2: SUMIDA CDRH125-270 LTC1143/LTC1143L LTC1143L-ADJ + C + IN5 22 F 25V 2 5 P1B V IN5 P-DRIVE 5 SENSE5 SENSE 5 0.01 F – SENSE GND5 MBRS140T3 ...
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... AVX TPSD226K025R0200 IN1 IN2 AVX TPSE227M010R0100 OUT1 OUT2 L1: SUMIDA CDRH125-270 L2: PULSE ENGINEERING PE-53718 3.5V TO 10V 13 V IN1 P-DRIVE 1 P-DRIVE 2 + SENSE 1 SENSE LTC1143L-ADJ – SENSE 1 SENSE V FB1 C GND1 TH2 T2 TH1 ...
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... DWG # 05-08-1610 0.228 – 0.244 (5.791 – 6.197 0.053 – 0.069 (1.346 – 1.752) 0.014 – 0.019 (0.355 – 0.483) LTC1143/LTC1143L LTC1143L-ADJ 0.386 – 0.394* (9.804 – 10.008 0.150 – 0.157** (3.810 – 3.988 0.004 – ...
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... R : KRL SL-1/2-C1-0R033J SENSE3 R : KRL SL-1/2-C1-0R050J SENSE5 Synchronous Equivalent to LTC1143, 4V < V Synchronous Equivalent to LTC1143L-ADJ, 3.5V < < V (1/2) LTC1143L-ADJ in SO-8 Single Channel with Internal Switch Constant Frequency Current Mode, Drives Synchronous N-Channel MOSFETS Up to Four Output Voltages from G28 Package Full Featured Dual Controller in G36 Package ...