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FUJITSU SEMICONDUCTOR
DS04-27604-2E
DATA SHEET
ASSP For Power Supply Applications
Power Management 2-ch Switch IC
MB3842/MB3845
n DESCRIPTION
The MB3842/3845 is a power management switch with built-in 2-channel low-on resistance (typ. 100mW ) switch.
Output control is by means of a control signal, and the MB3842 is designed for high-active operation (output on
when EN is Hi), while the MB3845 is designed for low-active operation (output on when EN is low.)
To provide adaptability to a variet
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MB3842/MB3845 n PIN ASSIGNMENT EN1, EN1 1 20 GND SS1 2 19 OC1 CS1 3 18 OUT1 VIN1 4 17 OUT1 SSOP-20P (FPT-20P-M03) VIN1 5 16 OUT1 VIN2 6 15 OUT2 VIN2 7 14 OUT2 CS2 8 13 OUT2 SS2 9 12 OC2 EN2, EN2 10 11 GND EN Enable EN Enable SS Slow Start CS Current Set OC Over Current The functions of pin 1 and pin 10 differ on the MB3842 and MB3845. EN for MB3842/EN for MB3845 2
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MB3842/MB3845 n PIN DESCRIPTION Pin no. Symbol Descriptions Control signal input pin. EN Set “H” to turn switch on, “L” to turn toff. At 0.8 V or less, the chip is in STBY state (MB3842) and current consumption is less than 1m A. “L” level is 1.4V (typ), “H” level is 1.6V (typ), with 200mV (typ) hysteresis. Control signal input pin. 1/10 Set “L” to turn switch on, “H” to turn off. EN At “H” level = VIN, the chip is in STBY state and current consumption is less than (MB3845) 1m A. Normally used
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MB3842/MB3845 n BLOCK DIAGRAM (for 1 channel) MB3842 OUT1 CS1 Over current Charge detection 1 pump1 COMP SS1 - Q S FF1 R EN1 OSC1 COMP - OC1 VIN1 BGR1 Temperature protection 1 MB3845 OUT1 CS1 Charge Over current pump1 detection 1 COMP SS1 - Q S FF1 R EN1 OSC1 COMP - OC1 VIN1 BGR1 Temperature protection 1 4 + + + +
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MB3842/MB3845 n ABSOLUTE MAXIMUM RATINGS Rating Parameter Symbol Condition Unit Max. Min. Input voltage VIN — –0.3 7.0 V ENABLE voltage VEN — –0.3 7.0 V Switch current ISW ——1.8A Power dissipation PD Ta = +85 C — 216 mW Storage temperature TSTG — –55 +125 C WARNING: Semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.) in excess of absolute maximum ratings. Do not exceed these ratings. n RECOMMENDED OPERATING CONDITIONS Value Paramet
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MB3842/MB3845 n ELECTRICAL CHARACTERISTICS (per 1 ch) •MB3842/MB3845 (VIN = 5 V, Ta = +25 C) Value Parameter Symbol Condition Unit Min. Typ. Max. Switch resistance RON ISW =0.6A — 100 150 mW IIN1 ISW = 0 A — 350 550 m A IIN2 ISW = 0.6 A — 1.0 1.5 mA IN pin input current EN < 0.8V for MB3842, IIN3 —— 1.0 m A EN = VIN for MB3845 VIUH VIN at OC = L fi H 2.1 2.3 2.5 V UVLO threshold VIUL VIN at OC = H fi L 1.9 2.1 2.3 V UVLO hysteresis width VIUHY VIUHY = VIUH – VIUL 100 200 300 mV ISWH RLIM =
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MB3842/MB3845 n DIAGRAM • Normal operation 5 V VIN Hi EN EN Low SW OFF SW ON SW ON 5 V VOUT Overcurrent does not occur IOUT OC 5 V •At VIN fall 5 V 2.3 V VIN 2.1 V Hi EN EN Low SW ON SW ON SW ON 5 V VOUT Overcurrent does not occur IOUT 5 V OC = 0 V Note: The OC pin should be pulled up using a separate power supply and resistance. (This illustration shows pull-up with a separate 5V source.) (Continued) 7
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MB3842/MB3845 (Continued) • At overcurrent detection 5 V VIN Hi EN EN Low SW ON OFF ON OFF 5 V VOUT IOUT 5 V OC = 0 V • At over-temperature occurrence 5 V Over-temperature VIN Over-temperature corrected occurs Hi EN EN Low SW ON SW OFF 5 V VOUT Overcurrent does not occur IOUT 5 V OC = 0 V Latch released Latch set Note: The OC pin should be pulled up using a separate power supply and resistance. (This illustration shows pull-up with a separate 5V source.) 8
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MB3842/MB3845 n TYPICAL CHARACTERISTICS •RLIM vs. limit current characteristics These are the limiting value characteristics for CS pin-to-GND external resistance and output current (OC flag). 10 1 VIN = 5.0 V VIN = 3.3 V VIN = 2.5 V 0.1 0.01 100 1000 10000 100000 RLIM (W ) •CSS vs. TON (SS) characteristics There are the characteristics for SS pin-to-GND external capacitance and output ON time. 100 10 VIN = 5.0 V VIN = 3.3 V VIN = 2.5 V 1 0.1 10 100 1000 10000 100000 CSS (pF) (Continued)
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MB3842/MB3845 (Continued) • SW resistance vs. temperature characteristics 150 140 130 120 W 110 at 0.1 A 100 at 0.6 A at 1 A 90 80 70 60 50 - 60 - 40 - 20 0 20 40 60 80 100 120 Temperature Ta ( C) • Temperature-depended SW resistance vs. VIN (V) characteristics 150 140 130 W 120 110 - 40 C 25 C 100 100 C 90 80 70 60 50 2345 6 7 VIN voltage (V) (Continued) 10 SW resistance (m ) SW resistance (m )
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MB3842/MB3845 (Continued) • Output power (ISW) saturation characteristics 5 V Measurement circuit VIN EN, EN OC VIL/VIH “Open” SS ISW OUT A CS GND 2 W 100 kW RLIM VSW 5 V These are the output saturation current characteristics in overcurrent state.(when not controlled by the OC pin warning flag) 1600 1400 RLIM not limited (CS GND) 1200 1000 RLIM set to 2.0kW , 0.6A Unlimited 6.2 k (0.1 A) 800 2 k (0.6 A) Overcurrent flag set (when set for 0.6A) 600 Temperature protection range 400 RLIM set to
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MB3842/MB3845 (Continued) • OC pin flag pull-up resistance (pull-up power 5V) dependant overcurrent operation 1 V / 500 NS 50 kW 1 V / 500 NS 1 kW GND 1 V / 500 NS 10 kW 1 V / 500 NS 100 kW • Power derating characteristics 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 Temperature Ta ( C) 12 Power dissipation PD (W)
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MB3842/MB3845 n 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 (VIN = 5 V, current limit at 600mA). Because the setting value is dependent on VIN voltage, the user should select the optimum resistance value for the value of VIN voltage . When the switching current exceeds the set value, the OC pin goes to “L” level as an external notification signal, but there is no latc
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MB3842/MB3845 n TYPICAL APPLICATION Top View MB3842/MB3845 EN1 GND Control signal EN1 Pull-up resistance CSS SS1 OC1 RLIM CS1 OUT1 VIN1 OUT1 Load VIN1 OUT1 VIN2 OUT2 VIN2 OUT2 Load RLIM CS2 OUT2 Pull-up resistance CSS SS2 OC2 EN2 GND Control signal EN2 14
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MB3842/MB3845 n APPLICATION EXAMPLE (1) Dual-Port Self-Powered Hub Application (NON-GANG Mode Connection) USB 5 V Controller Overcurrent MB3842/MB3845 ON/OFF GND EN1,EN1 SS1 OC1 OUT1 CS1 VIN1 OUT1 USB Port 1 Power Supply VIN1 OUT1 5 V OUT2 VIN2 USB Port 2 VIN2 OUT2 CS2 OUT2 SS2 OC2 EN2,EN2 GND *The MB3842 can also be adapted for use with 3.3V controllers. USB Port 500mA MAX Par Port Smoothing capacitors should be placed between VIN and GND, or between OUT and GND as required. 15
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MB3842/MB3845 (2) Dual-Port Bus Powered Hub Application (GANG Mode Connection) USB Overcurrent MB3842/MB3845 ON/OFF EN1,EN1 GND SS1 OC1 USB Port1(· 4) CS1 OUT1 VIN1 OUT1 400 mA MAX (100 mA · 4) VIN1 OUT1 5 V Upstream Port VIN2 OUT2 USB Port2(· 4) VIN2 OUT2 CS2 OUT2 400 mA MAX (100 mA · 4) SS2 OC2 EN2,EN2 GND USB Port 100mA MAX Par Port Smoothing capacitors should be placed between VIN and GND, or between OUT and GND as required. 16
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MB3842/MB3845 n USAGE PRECAUTION 1. Never use settings exceeding 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 this device within recommended operating conditions. Recommended operating conditions are values within which normal LSI operation is warranted. Standard elec
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MB3842/MB3845 n PACKAGE DIMENSION *: These dimensions do not include resin protrusion. 20-pin plastic SSOP (FPT-20P-M03) +0.20 * 6.50±0.10(.256±.004) 1.25 –0.10 (Mounting height) +.008 .049 –.004 0.10(.004) INDEX * 4.40±0.10 6.40±0.20 5.40(.213) (.173±.004) (.252±.008) NOM "A" +0.10 +0.05 Details of "A" part 0.65±0.12 0.22 –0.05 0.15 –0.02 +.004 +.002 (.0256±.0047) .009 –.002 .006 –.001 0.10±0.10(.004±.004) (STAND OFF) 0 10° 0.50±0.20 5.85(.230)REF (.020±.008) Dimensions in mm (inches). C 1
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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 incorporated in devices for actual use. Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of thir
