mc33680ftb ON Semiconductor, mc33680ftb Datasheet

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... Semiconductor Components Industries, LLC, 2006 July, 2006 − Rev VAUXSW VAUXEMR LIBATIN LIBATOUT NC VMAINGND VMAINSW VMAIN Device MC33680FTB MC33680FTBR2 1 http://onsemi.com 32 1 32−LEAD LQFP FTB SUFFIX CASE 873A PIN CONNECTIONS & DEVICE MARKING NC DGND MC33680 LIBATCL ...

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CPOR RIref 80 nF 480 kW 8 IREF 7 AGND 6 VREF VBAT 300 kW RLBa LOBAT− SEN 9 900 kW RLBb DGND 10 PORB Power−On Reset 11 x2 1.22 V Voltage COMP1 Reference Main Regulator with Synchronous Rectifier 0.5 ...

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TIMING DIAGRAMS VBAT V − 0.15 V MAINreg VMAIN PORB VAUXEN VBAT LOWBAT Threshold LOWBATB VMAIN PORB T POR t PORC Figure 2. Startup Timing Figure 3. Power Down Timing http://onsemi.com 3 V MAINreg + 1.22 C por RIref 0.5 ...

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Pin No. Function Type/Direction Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á 1 VMAINFB Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á ...

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ABSOLUTE MAXIMUM RATINGS Parameter Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Á Power Supply Voltage Digital Pin Voltage Á Á Á Á Á Á Á Á Á Á Á Á Á Á ...

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DYNAMIC ELECTRICAL CHARACTERISTICS Rating Minimum PORB to Control delay 90% 85% 80 1. MAIN ...

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60 1. 1. AUX OUTPUT CURRENT (mA) OUT_AUX Figure 8. Efficiency of VAUX ...

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VMAIN = 3.3 V (50 mV/div, AC COUPLED) 2: Voltage at VMAINSW (1 V/div) Figure 12. VMAIN Output Ripple (Medium Load div 1: VAUX = 20 V (50 mV/div, AC COUPLED) 2: ...

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DETAILED OPERATING DESCRIPTION General The MC33680 is a dual DC−DC regulator designed for electronic organizer applications. Both regulators apply Pulse−Frequency−Modulation (PFM). The main boost regulator output can be externally adjusted from 2.7V to 5V. An internal synchronous rectifier is used ...

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DETAILED OPERATING DESCRIPTION (Cont’ Iref 1 x2 0.5 V Iref IREF 8 RIref 480 kOhm 1.22 V Voltage COMP1 Reference AGND Voltage Reference Main Regulator & Current Bias with Synchronous Rectifier Figure 18. Simplified Block Diagram of Main ...

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VREF Feedback Voltage OFF I pk Loading Current, I LOAD Coil Current VMAIN + 1 V VMAIN V@SW VMAIN Zoom−In Figure 19. Waveforms of Continuous Conduction Mode Feedback Voltage VREF ...

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DETAILED OPERATING DESCRIPTION (Cont’d) Synchronous Rectification A Synchronous Rectifier is used in the main regulator to enhance efficiency. Synchronous rectifier is normally realized by powerFET with gate control circuitry which, however, involved relative complicated timing concerns. In Figure 19, as ...

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DETAILED OPERATING DESCRIPTION (Cont’d) Current Limit for Both regulators From Figure 18 and Figure 21, sense devices (senseFET or senseBJT) are applied to sample coil current as the low−side switch is ON. With that sample current flowing through a sense ...

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... Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303− ...