Description, Features, Package | Fujitsu MB39A104 instruction

FUJITSU SEMICONDUCTOR

DATA SHEET

DS04-27231-3E

ASSP For Power Management Applications (General Purpose DC/DC Converter)

2-ch DC/DC Converter IC

with Overcurrent Protection

MB39A104

■DESCRIPTION

The MB39A104 is a 2-channel DC/DC converter IC using pulse width modulation (PWM), incorporating an overcurrent protection circuit (requiring no current sense resistor). This IC is ideal for down conversion.

Operating at high frequency reduces the value of coil.

This is ideal for built-in power supply such as LCD monitors and ADSL.

This product is covered by US Patent Number 6,147,477.

■FEATURES

•Built-in timer-latch overcurrent protection circuit (requiring no current sense resistor)

•Power supply voltage range : 7 V to 19 V

•Reference voltage : 5.0 V ± 1 %

•Error amplifier threshold voltage : 1.24 V ± 1 %

•High-frequency operation capability : 1.5 MHz (Max)

•Built-in standby function: 0 ∝A (Typ)

•Built-in soft-start circuit independent of loads

•Built-in totem-pole type output for Pch MOS FET

■PACKAGE

24-pin plastic SSOP

(FPT-24P-M03)

Image 1

Fujitsu MB39A104 manual Description, Features, Package

Contents

Description FeaturesPackage PIN Assignments MB39A104 PIN Description Pin No Symbol Descriptions Block Diagram Parameter Symbol Condition Value Unit Min Typ Parameter Symbol Condition Rating Unit Min MaxAbsolute Maximum Ratings Recommended Operating Conditions Parameter Electrical CharacteristicsPin No Conditions Min Typ Max Pin No Conditions Value Unit Min Parameter Symbol Reference Voltage vs. Ambient Temperature Typical Characteristics Triangular Wave Oscillation Frequency Power Dissipation vs. Ambient Temperature Functions Under voltage lockout protection circuit Uvlo Timer-latch overcurrent protection circuit block OCPProtection circuit operating function table Operating circuit Setting the Triangular Oscillation Frequency Setting the Output Voltage Setting the SOFT-START and Discharge Times MB39A104 Without Setting Soft-Start Time Treatment Without Using CS Terminal Overcurrent detection circuit About TIMER-LATCH Protection Circuit Method to detect by mean current Overcurrent Protection Circuit Range of Operation Timer-latch short-circuit protection circuit Resetting the Latch of Each Protection Circuit Treatment Without Using Cscp Terminal Equivalent Circuit On Power on OFF Standby mode Component Specification Vendor Parts List CH1 Selection of Components CH2 = 3 2 ⋅ 0.05 ⋅ 0.174 = 0.078 W Example Peak-to-peak value ΔIL Di ≥ I O ⋅ 1 − ESR ≤ ΠfC L 050 491 ESR ≤ ΠfC L 033 364 Total Efficiency vs. Input Voltage Reference Data Switching Wave Form CH1 Ordering Information Usage PrecautionDo not apply negative voltages Part number Package Remarks Index Package Dimensions Fujitsu Limited