LX1671 Microsemi Corporation, LX1671 Datasheet
LX1671
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LX1671 Summary of contents
Page 1
... T (°C) A RoHS Compliant / Pb-free Transition DC: 0518 Note: Available in Tape & Reel. Append the letters “TR” to the part number (i.e. LX1671CPW-TR) Copyright © 2000 Rev. 1.2b, 2006-02-13 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 ® Multiple Output LoadSHARE™ PWM ...
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... A 85°C/W MBIENT JA , θ A 35°C/W MBIENT JA x θ Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET LO1 1 38 PG1 LO2 HO2 VC2 LDGD LDFB LDDIS DGND AGND RSVD ...
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... Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 ® Multiple Output LoadSHARE™ PWM ESCRIPTION Microsemi Integrated Products, Power Management LX1671 D S RODUCTION ATA HEET forces average current in 2 Page 3 ...
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... I = 20mA, CCL DH SOURCE V = 12V 20mA, CCL DL SINK RAMP Microsemi Integrated Products, Power Management LX1671 D S RODUCTION ATA HEET ≤ ≤ T 70°C except where A LX1671 Min Typ Max 4.5 5 0.8 0.784 0.816 - 250 85 -6.0 6 3.8 5.0 100 0.1 3.5 100 260 ...
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... LDFB OUT LDGD LDGD I Vout = 0.4V LDGD Threshold LDDIS Pulldown Resistance Microsemi Integrated Products, Power Management LX1671 D S RODUCTION ATA HEET ≤ ≤ T 70°C except where A LX1671 Min Typ Max 3.5 4.0 4.5 4.0 4.25 4.5 0 0.2 2 100 Units KΩ ...
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... S FAULT TEMP SS1 SS2 SS3 Figure 1 – Typical Block Diagram of Phase 1 and 3 LDGD V REF LDFB +5V LDDIS Figure 2 – LDO Controller Block Diagram Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET I SET V (5V) +12V VCX HOX ...
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... SET I RESET PWM Hiccup UVLO Ramp UVLO Oscillator S FAULT TEMP SS1 SS2 SS3 Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET I SET +5V V (12V) IN VC2 C IN HO2 L2 ESR C OUT LO2 PG1 +5V VCCL +5V 16V ...
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... PG3 LDFB VCCL LDDIS VCC +5V DGND N/U LX1671 AGN VS3 CPW D L3 RSVD CS3 SS2 N.C. RF2 N.C. FB2 EO3 EO2 FB3 CS2 SS3 VS2 VS1 SS1 CS1 FB1 EO1 Microsemi Integrated Products, Power Management LX1671 D S RODUCTION ATA HEET + VOUT1 VOUT3 Page 8 ...
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... PG3 VCCL VCC N/U + VS3 CPW CS3 N.C. N.C. EO3 FB3 SS3 VS1 CS1 EO1 Figure 5 – Single Phase Operation 5V Only (ALL PHASES BOOTSTRAPPED) (LDO NOT FUNCIONAL ) Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET + + + VOUT1 VOUT2 VOUT3 Page 9 ...
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... LDFB VCCL LDDIS VCC DGND N/U LX1671 AGN VS3 CPW D L3 RSVD CS3 SS2 N.C. RF2 N.C. FB2 EO3 EO2 FB3 CS2 SS3 VS2 VS1 SS1 CS1 FB1 EO1 Microsemi Integrated Products, Power Management LX1671 D S RODUCTION ATA HEET +5V L1 +3.3V L2 +5V VOUT1 VOUT3 Page 10 ...
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... This will force the current in the phase 2 inductor to follow and be equal to the current in the phase 1 inductor. There are four methods that can be used to implement the LoadSHARE feature of the LX1671 in the Bi-Phase mode of operation. Microsemi Integrated Products, Power Management ...
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... V2. The high DC gain of the error amplifier will 4.67A force LPF2 to always be equal to LPF1. calculations determine the value of the resistor divider necessary to satisfy this example. 1.5V @ 12A 18W 7.33A Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET SHARE ( ...
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... FB2 Generator Figure 8 – LoadSHARE Using Feedback Divider Offset V 1 × K 100 TBD 5.814 then − Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET + ESR L1 V1 1.5V 10mΩ 4.67A +46.7mV Phase 1 - Offset Voltage + 1.5V @ 12A ESR L2 V2 10mΩ ...
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... Offset Amp Vos Rin - Rf Phase 2 Error Amp PWM Input - Generator FB2 62k Rb 1M Figure 9 – LoadSHARE Using Proportional Control Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET + ESR L1 1.5V V 10mΩ 4.67A 1 +46.7mV Phase 1 - Offset Voltage + 1 ...
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... Max offset Error = 6mV ⎞ +5% ESR L1 = 6.3 mΩ ⎟ ⎠ -5% ESR L2 = 5.7 mΩ Phase Phase 2 current is 2.32A greater than Phase 1. Input bias current also contributes to imbalance. Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET SHARE ( ERIES ESISTOR ...
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... The CDE Polymer AL-EL (ESRE) filter series provides excellent ESR performance at a reasonable cost. Beware of off- brand, very low-cost filter capacitors, which have been shown to degrade in both ESR and general electrolytic characteristics over time. D × Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET ( ) × + < ...
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... Short circuit protection still exists due to the narrow pulse width even though the magnitude of the current pulses will be higher than the calculated value. If OCP is not desired connect both VSX and VCX to VCC. Do not leave them floating. Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET ...
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... TT and receiver supply voltage (VDD). requirement VDD is generally equal to VDDQ so that only V VDDQ are required. The LX1671 can supply both voltages by using two of the three PWM phases. Since the currents for V ) which X are quite often several amps, ( common) a switching ...
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... LDDIS pin will keep the LDO off until this capacitor, being charge by the 100K pull down resistor, goes through the low input threshold level. Microsemi Integrated Products, Power Management LX1671 D S ATA HEET resistor value is 1k ohm for the current ...
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... *LC L Dim Microsemi Integrated Products, Power Management LX1671 RODUCTION ATA HEET M I ILLIMETERS NCHES MIN MAX MIN MAX 0.85 0.95 0.033 0.037 0.19 0.25 0.19 0.009 0.09 0.20 0.003 0.008 9.60 9.80 0.378 0.390 4.30 4.50 0.169 ...
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... Copyright © 2000 Rev. 1.2b, 2006-02-13 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 ® Multiple Output LoadSHARE™ PWM P RODUCTION Microsemi Integrated Products, Power Management LX1671 D S ATA HEET Page 21 ...