Instruction/ maintenance manual of the product MB3842 Fujitsu
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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.
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.
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.
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 MB384.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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 .
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/M.
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) 4.
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.
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.
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.
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