Fujitsu MB3845, MB3842 manual Description, Features, Package

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FUJITSU SEMICONDUCTOR

DATA SHEET

DS04-27604-2E

ASSP For Power Supply Applications

Power Management 2-ch Switch IC

MB3842/MB3845

DESCRIPTION

The MB3842/3845 is a power management switch with built-in 2-channel low-on resistance (typ. 100mΩ) 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 variety of operations, the MB3842/3845 features low input voltage (VIN > 2.5V) operation and stable low-on resistance independent of input voltage. The switching current limit can be set from 100mA to 600mA by using external resistance, and when overcurrent conditions are detected the OC output goes low to provide an external notification signal.

VIN is divided between the two channels, which operate independently of each other.

In addition, an off-state reverse current prevention function is provided to ensure accurate on/off switching action.

FEATURES

Low on resistance switch (typ. 100mΩ)

Low input voltage operation (2.5 V to 5.5 V)

Switch current (max. 0.6 A)

• UVLO

:VIN threshold

2.3V/2.1 V hysteresis 200 mV

• ENABLE

:EN threshold

EN 1.4V/1.6 V for MB3842,

EN

1/2 VIN for MB3845

 

:Power supply current at output off = 0A EN < 0.8V for MB3842,

 

= VIN for MB3845

 

EN

External setting for soft start time and switch current limit.

Over-temperature detection (switch latched off), over-current detection (not latched)

OC pin flag set following overcurrent detection, over-temperature detection, or UVLO detection.

Reverse current prevention at OFF (VIN 1.5 V)

Either channel may be operated alone.

PACKAGE

20-pin plastic SSOP

(FPT-20P-M03)

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Contents Description FeaturesPackage PIN Assignment MB3842/MB3845PIN Description Pin no Symbol DescriptionsBlock Diagram for 1 channel Recommended Operating Conditions Absolute Maximum RatingsElectrical Characteristics per 1 ch Normal operation DiagramAt V in fall At overcurrent detection At over-temperature occurrenceRlim vs. limit current characteristics Typical CharacteristicsCSS vs. TON SS characteristics MB3842/MB3845 SW resistance vs. temperature characteristicsOutput power ISW saturation characteristics Power derating characteristics Functional Description Typical Application Application Example Dual-Port Bus Powered Hub Application Gang Mode Connection Ordering Information Usage PrecautionPackage Dimension Fujitsu Limited