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Fujitsu MB3842 manual

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Table of contents for the manual

  • Page 1

    DS04-27604-2E FUJITSU SEMICONDUCT OR DA T A S H E E T ASSP F or P o wer Supply Applications P o wer Mana g ement 2-c h Switch IC MB3842/MB3845 ■ DESCRIPTION The MB3842/3845 is a power management switch with built-in 2-channel low-on resistance (typ. 100m Ω ) switch. Output control is by means of a control signal, and the MB3842 is designed for [...]

  • Page 2

    2 MB3842/MB3845 ■ PIN ASSIGNMENT 20 19 18 17 16 15 14 13 12 11 GND OC1 OUT1 OUT1 OUT1 OUT2 OUT2 OUT2 OC2 GND 1 2 3 4 5 6 7 8 9 10 EN1, EN1 SS1 CS1 VIN1 VIN1 VIN2 VIN2 CS2 SS2 EN2, EN2 SSOP-20P (FPT-20P-M03) EN Enable CS Current Set OC Over Current EN Enable SS Slow Start The functions of pin 1 and pin 10 diff er on the MB3842 and MB3845. EN f or [...]

  • Page 3

    3 MB3842/MB3845 ■ PIN DESCRIPTION Pin no. Symbol Descriptions 1/10 EN (MB3842) Control signal input pin. Set “H” to tur n s witch on, “L” to turn toff. At 0.8 V or less , the chip is in STBY state and current consumption is less than 1 µ A. “L” le vel is 1.4V (typ), “H” le vel is 1.6V (typ), with 200mV (typ) h ysteresis. EN (MB38[...]

  • Page 4

    4 MB3842/MB3845 ■ BLOCK DIA GRAM (for 1 c hannel) SS1 EN1 VIN1 OSC1 BGR1 + − COMP FF1 Q S R OC1 OUT1 CS1 + − COMP MB3842 SS1 EN1 VIN1 OSC1 BGR1 + − COMP FF1 Q S R OC1 OUT1 CS1 + − COMP MB3845 Temperature protection 1 Charge pump1 Over current detection 1 Charge pump1 Over current detection 1 Temperature protection 1[...]

  • Page 5

    5 MB3842/MB3845 ■ ABSOLUTE MAXIMUM RA TINGS W ARNING: Semiconductor de vices can be per manently damaged by application of stress (v oltage, current, temperature , etc.) in e xcess of absolute maximum ratings. Do not e xceed these ratings. ■ RECOMMENDED OPERA TING CONDITIONS * : F or C SS , R LIM settings, see “TYPICAL CHARA CTERISTICS” and[...]

  • Page 6

    6 MB3842/MB3845 ■ ELECTRICAL CHARA CTERISTICS (per 1 ch) • MB3842/MB3845 (V IN = 5 V , T a = +25 ° C) • MB3842 (V IN = 5 V , T a = +25 ° C) • MB3845 (V IN = 5 V , T a = +25 ° C) Parameter Symbol Condition Value Unit Min. Typ. Max. Switch resistance R ON I SW =0.6A — 100 150 m Ω IN pin input current I IN1 I SW = 0 A — 350 550 µ A I[...]

  • Page 7

    7 MB3842/MB3845 ■ DIA GRAM (Continued) VIN EN EN V OUT I OUT OC SW OFF Overcurrent does not occur SW ON SW ON 5 V Hi Low 5 V 5 V • Normal operation SW ON SW ON SW ON 2.3 V 2.1 V 5 V Hi Low 5 V 5 V = 0 V VIN EN EN V OUT I OUT OC Overcurrent does not occur •A t V IN fall Note: The OC pin should be pulled up using a separ ate power supply and re[...]

  • Page 8

    8 MB3842/MB3845 (Continued) SW ON OFF ON OFF VIN EN EN V OUT I OUT OC 5 V Hi Low 5 V 5 V = 0 V • At o vercurrent detection SW ON Over-temperature corrected Over-temperature occurs SW OFF VIN EN EN V OUT I OUT OC 5 V Hi Low 5 V 5 V = 0 V Overcurrent does not occur Latch set Latch released • At o ver-temperature occurrence Note: The OC pin should[...]

  • Page 9

    9 MB3842/MB3845 ■ TYPICAL CHARA CTERISTICS (Continued) V IN = 5.0 V V IN = 3.3 V V IN = 2.5 V 10 1 0.1 0.01 100 1000 10000 100000 R LIM ( Ω ) I SW (A) •R LIM vs. limit current characteristics V IN = 5.0 V V IN = 3.3 V V IN = 2.5 V 100 10 1 0.1 10 100 1000 10000 100000 C SS (pF) t ON (ms) •C SS vs. T ON (SS) characteristics These are the lim[...]

  • Page 10

    10 MB3842/MB3845 (Continued) (Continued) 150 140 130 120 110 100 90 80 70 60 50 − 60 − 40 − 20 0 20 40 60 80 100 120 at 0.1 A at 0.6 A at 1 A − 40 ° C 25 ° C 100 ° C 150 140 130 120 110 100 90 80 70 60 50 234567 • SW resistance vs. temperature characteristics • T emperature-depended SW resistance vs. V IN (V) characteristics SW resis[...]

  • Page 11

    11 MB3842/MB3845 (Continued) (Continued) 5 V 5 V 100 k Ω 2 Ω VIN I SW V SW R LIM GND EN, EN OC OUT SS CS V IL /V IH A 1600 1400 1200 1000 800 600 400 200 0 02 3 4 5 6 1 I SW (mA) 6.2 k (0.1 A) 2 k (0.6 A) V SW (V) Measurement circuit These are the output saturation current characteristics in overcurrent state.(when not controlled by the OC pin [...]

  • Page 12

    12 MB3842/MB3845 (Continued) • P ower derating c haracteristics Power dissipation P D (W) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 − 20 0 20 40 60 80 100 1 V / 500 NS 50 k Ω Temperature Ta ( ° C) 1 V / 500 NS 1 k Ω GND 1 V / 500 NS 10 k Ω 1 V / 500 NS 100 k Ω • OC pin flag pull-up resistance (pull-up po wer 5V) dependant over current [...]

  • Page 13

    13 MB3842/MB3845 ■ FUNCTIONAL DESCRIPTION Current Limit Setting By placing resistance between the CS and GND pins, the current limit can be set between 100mA and 600mA within ±30% accuracy (V IN = 5 V, current limit at 600mA). Because the setting value is dependent on V IN voltage, the user should select the optimum resistance value for the valu[...]

  • Page 14

    14 MB3842/MB3845 ■ TYPICAL APPLICA TION C SS R LIM R LIM C SS EN1 EN1 SS1 CS1 VIN1 VIN1 VIN2 VIN2 CS2 SS2 EN2 EN2 GND OC1 OUT1 OUT1 OUT1 OUT2 OUT2 OUT2 OC2 GND MB3842/MB3845 Top View Control signal Control signal Pull-up resistance Load Load Pull-up resistance[...]

  • Page 15

    15 MB3842/MB3845 ■ APPLICA TION EXAMPLE (1) Dual-P or t Self-P owered Hub Application (NON-GANG Mode Connection) 5 V USB 5 V Controller Overcurrent ON/OFF Power Supply USB Port 1 USB Port 2 MB3842/MB3845 EN1,EN1 SS1 CS1 VIN1 VIN1 VIN2 VIN2 CS2 SS2 EN2,EN2 GND OC1 OUT1 OUT1 OUT1 OUT2 OUT2 OUT2 OC2 GND *The MB3842 can also be adapted for use with 3[...]

  • Page 16

    16 MB3842/MB3845 (2) Dual-P or t Bus P owered Hub Application (GANG Mode Connection) USB Overcurrent ON/OFF 5 V Upstream Port MB3842/MB3845 USB Port1( × 4) USB Port2( × 4) 400 mA MAX (100 mA × 4) 400 mA MAX (100 mA × 4) EN1,EN1 SS1 CS1 VIN1 VIN1 VIN2 VIN2 CS2 SS2 EN2,EN2 GND OC1 OUT1 OUT1 OUT1 OUT2 OUT2 OUT2 OC2 GND USB Port 100mA MAX Par Port [...]

  • Page 17

    17 MB3842/MB3845 ■ USA GE PRECA UTION 1. Never use settings e xceeding maximum rated conditions. Exceeding maximum rated conditions may cause permanent damage to the LSI. Also, it is recommended that recommended operating conditions be observed in normal use. Exceeding recommended operating conditions may adversely affect LSI reliability. 2. Use [...]

  • Page 18

    18 MB3842/MB3845 ■ P A CKA GE DIMENSION C 1994 FUJITSU LIMITED F20012S-2C-4 0.50±0.20 (.020±.008) 0.10±0.10(.004±.004) (STAND OFF) 0 10° Details of "A" part 5.85(.230)REF 6.50±0.10(.256±.004) * 0.65±0.12 5.40(.213) 4.40±0.10 6.40±0.20 NOM (.252±.008) (.173±.004) * (.0256±.0047) .006 –.001 +.002 –0.02 +0.05 0.15 .009 –[...]

  • Page 19

    MB3842/MB3845 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. The information and circuit diagrams in this document are presented as examples of semiconductor device applications, and are not intended to be i[...]