Instruction/ maintenance manual of the product MB3878 Fujitsu
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DS04-27706-2E FUJITSU SEMICONDUCT OR DA T A S H E E T ASSP F or P o wer Supply Applications (Secondar y batter y) DC/DC Con ver ter IC f or Char ging MB3878 ■ ■ ■ ■ DESCRIPTION The MB3878 is a.
MB3878 2 (Continued) • Built-in current detector amplifier with wide in-phase input v oltage range : 0 V to Vcc • In standb y mode, leav e output voltage setting resistor open to pre vent ineffici.
MB3878 3 ■ ■ ■ ■ PIN DESCRIPTION Pin No. Symbol I/O Descriptions 1 − INC2 I Current detection amplifier (Current Amp. 2) input pin. 2 OUTC2 O Current detection amplifier (Current Amp. 2) output pin. 3 + INE2 I Error amplifier (Error Amp. 2) non-inverted input pin.
MB3878 4 ■ ■ ■ ■ BLOCK DIA GRAM + − − + 8 10 13 12 9 + − − + 4 2 24 1 3 × 25 × 25 + + + − 5 20 21 19 − + + + − 11 16 22 17 6 23 14 18 <Current Amp.1> <Error Amp.1> 7 VREF <Current Amp.2> <Error Amp.2> VREF <Error Amp.
MB3878 5 ■ ■ ■ ■ ABSOLUTE MAXIMUM RA GINGS * : The package is mounted on the dual-sided epo xy board (10 cm × 10 cm). W ARNING: Semiconductor de vices can be per manently damaged by application of stress (v oltage, current, temperature , etc.
MB3878 6 ■ ■ ■ ■ ELECTRICAL CHARA CTERISTICS (Ta = + 25 ° C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) * : Standard design v alue. (Continued) Parameter Symbol Pin No. Conditions Value Unit Min Typ Max Reference voltage block (Ref) Output voltage V REF 6 Ta = + 25 ° C 4.
MB3878 7 (Ta = + 25 ° C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) * : Standard design v alue. (Continued) Parameter Symbol Pin No. Conditions Value Unit Min Typ Max Error amplifier block (Error Amp.3) Threshold voltage V TH1 16 FB3 = 2 V, Ta = + 25 ° C 4.
MB3878 8 (Continued) (Ta = + 25 ° C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) * : Standard design v alue Parameter Symbol Pin No. Conditions Value Unit Min Typ Max Current detection amplifier block (Current Amp.1, Current Amp.2) Output voltage V OUTCH 2, 10 4.
MB3878 9 ■ ■ ■ ■ TYPICAL CHARA CTERISTICS (Continued) Ta = + 25 ° C CTL = 5 V 12 10 8 6 4 2 0 0 5 10 15 20 25 Ta = + 25 ° C CTL = 5 V VREF = 0 mA 10 8 6 4 2 0 0 5 10 15 20 25 Ta = + 25 ° C VCC = 19 V CTL = 5 V 10 8 6 4 2 0 0 5 10 15 20 25 30 2.
MB3878 10 (Continued) Ta = + 25 ° C VCC = 19 V CTL = 5 V 1 M 100 k 10 k 10 k 100 k 1 M Ta = + 25 ° C CTL = 5 V RT = 47 k Ω 340 330 320 310 300 290 280 270 260 250 240 0 5 10 15 20 25 VCC = 19 V CTL = 5 V RT = 47 k Ω 340 330 320 310 300 290 280 270 260 250 240 − 40 − 20 0 20 40 60 80 100 VCC = 19 V CTL = 5 V 5.
MB3878 11 (Continued) − + −+ VCC = 19 V Error Amp.1 (Error Amp.2) (3) (5) (4) 2.5 V 10 k Ω 2.4 k Ω 240 k Ω 10 k Ω 5.2 V 1 µ F OUT IN φ A V Ta = + 25 ° C 40 20 0 − 20 − 40 180 90 0 − 90 − 180 1 k 10 k 100 k 1 M 10 M 7 8 9 VCC = 19 V Current Amp.
MB3878 12 ■ ■ ■ ■ FUNCTIONAL DESCRIPTION 1. DC/DC Con ver ter Unit (1) Reference v oltage bloc k (Ref) The ref erence voltage generator uses the v oltage supplied from the VCC ter minal (pin 18) to generate a tem- perature-compensated, stab le voltage (5.
MB3878 13 (7) PWM comparator b lock (PWM Comp.) The PWM comparator circuit is a v oltage-pulse width conv er ter f or controlling the output duty of the error amplifiers (Error Amp .
MB3878 14 ■ ■ ■ ■ SETTING THE CHARGING V OL T A GE The charging v oltage (DC/DC output voltage) can be set b y connecting e xter nal voltage setting resistors (R3, R4) to the -INE3 ter minal.
MB3878 15 ■ ■ ■ ■ A C AD APT OR V OL T A GE DETECTION With an e xter nal resistor connected to the +INE2 ter m inal(pin 3), the IC enters the dynamically-controlled charging mode to reduce the.
MB3878 16 ■ ■ ■ ■ PR OCESSING WITHOUT USE OF THE CS PIN If the soft-star t function is not used, the CS ter minal (pin 22) should be left open.
MB3878 17 ■ ■ ■ ■ APPLICA TION EXAMPLE 1 + − − + 8 10 13 12 A B 9 + − − + 4 2 24 1 3 × 25 × 25 + + + − 5 20 21 19 − + + + − 11 16 22 17 6 23 14 18 <Current Amp.1> <Error Amp.1> 7 VREF <Current Amp.2> <Error Amp.
MB3878 18 ■ ■ ■ ■ P ARTS LIST (f or APPLICA TION EXAMPLE 1) Note VISHA Y SILICONIX : VISHA Y Inter technolog y, Inc. MO T OROLA : Motorola J apan Ltd.
MB3878 19 ■ ■ ■ ■ REFERENCE D A T A 100 98 96 94 92 90 88 86 84 82 80 10 m 100 m 1 10 100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 10 12 14 16 18 16 14 12 10 8 6 4 2 0 012345 DCC : Dynamically .
MB3878 20 ■ ■ ■ ■ APPLICA TION EXAMPLE 2 + − − + 8 10 13 12 A B C D 9 + − + − + − − + 4 2 24 1 3 × 25 × 25 + + + − 5 20 21 19 − + + + − 11 16 22 17 6 23 14 18 <Current Amp.1> <Error Amp.1> 7 VREF <Current Amp.
MB3878 21 ■ ■ ■ ■ P ARTS LIST (f or APPLICA TION EXAMPLE 2) Note VISHA Y SILICONIX : VISHA Y Inter technolog y, Inc. MO T OROLA : Motorola J apan Ltd.
MB3878 22 ■ ■ ■ ■ USA GE PRECA UTIONS • Printed cir cuit board gr ound lines should be set up with consideration f or common impedance. • T ake appropriate static electricity measures. • Containers f or semiconductor materials should ha v e anti-static protection or be made of conductive material.
MB3878 23 ■ ■ ■ ■ P A CKA GE DIMENSION 24-pin plastic SSOP (FPT-24P-M03) Note1: Pins width and pins thickness include plating thickness. Note2: * This dimension does not include resin protrusion. Dimensions in mm (inches) C 2001 FUJITSU LIMITED F24018S-c-3-4 7.
MB3878 FUJITSU LIMITED All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering.
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