MB3882PFV

Manufacturer Part NumberMB3882PFV
Description2-channel DC/DC Converter IC with Synchronous Rectifier
ManufacturerFUJITSU [Fujitsu Component Limited.]
MB3882PFV datasheet
 


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FUJITSU SEMICONDUCTOR
DATA SHEET
ASSP For Power Management Applications
2-channel DC/DC Converter IC
with Synchronous Rectifier
MB3882
DESCRIPTION
The MB3882 is a 2-channel DC/DC converter IC using pulse width modulation (PWM) and synchronous rectifi-
cation, designed for down conversion applications.
This device is a power supply with high output drive capacity. Synchronous rectification also provides for high
efficiency.
In addition, a 5 V regulator is built in to reduce the number of system components. The result is an ideal built-in
power supply for driving products with high speed CPU’s such as home TV game devices and notebook PC’s.
FEATURES
• Synchronous rectification for high efficiency
• Supply voltage range : 5.5 V to 18 V
• High-precision reference voltage : 2.5 V
• Error Amp. threshold voltage : 1.25 V
• Oscillator frequency range : 10 kHz to 500 kHz
• Built-in soft start circuit with error Amp. input control
• Totem pole type output for N-ch MOSFET
PACKAGE
1
1
(0 C to 85 C)
24-pin Plastic SSOP
(FPT-24P-M03)
DS04-27226-1E

MB3882PFV Summary of contents

  • Page 1

    FUJITSU SEMICONDUCTOR DATA SHEET ASSP For Power Management Applications 2-channel DC/DC Converter IC with Synchronous Rectifier MB3882 DESCRIPTION The MB3882 is a 2-channel DC/DC converter IC using pulse width modulation (PWM) and synchronous rectifi- cation, designed for down conversion applications. ...

  • Page 2

    MB3882 PIN ASSIGNMENTS SGND : 3 CS1 : 4 INE1 : 5 FB1 : 6 INC1 : 7 OUT1 VS1 : 9 CB1 : 10 OUT2 PGND : 12 2 ...

  • Page 3

    PIN DESCRIPTIONS Pin No. Symbol I Triangular wave oscillator frequency setting capacitor connection terminal 2 RT Triangular wave oscillator frequency setting resistor connection terminal 3 SGND Ground terminal 4 CS1 CH1 soft start capacitor connection terminal. (Also used ...

  • Page 4

    MB3882 BLOCK DIAGRAM 6 FB1 10 A Error Amp.1 5 INE1 4 CS1 1.25 V OVP Comp.1 7 INC1 VCC 1. FB2 10 A Error Amp.2 20 INE2 21 CS2 1.25 V OVP Comp.2 18 INC2 Latch1 VCC ...

  • Page 5

    ABSOLUTE MAXIMUM RATINGS Parameter Symbol Supply voltage V Boot voltage V Output current Peak output current I Power dissipation P Storage temperature Tstg * : The packages are mounted on the dual-sided epoxy board (10cm WARNING: Semiconductor devices can be ...

  • Page 6

    MB3882 RECOMMENDED OPERATING CONDITIONS Parameter Supply voltage Boot voltage Reference voltage output current Bias output current Input voltage Output current Peak output current Oscillator frequency Timing resistor Timing capacitor Boot capacitor Reference voltage output capacitor Bias output capacitor Soft start ...

  • Page 7

    ELECTRICAL CHARACTERISTICS Parameter Symbol Pin No. V REF Output voltage REF Reference Input stability Line Voltage Block Load stability Load [Ref] Short output Ios current 2. Bias Voltage Output voltage VB Block [VB] Threshold 3. V voltage ...

  • Page 8

    MB3882 Parameter Symbol Pin No. Frequency band width 7. Output voltage Error Amp Block Output source I [Error Amp.] current Output sink current 8. PWM Threshold Comparator voltage Block [PWM Comp.] 9. Dead time Maximum Adjustment duty cycle Block [DTC] ...

  • Page 9

    Parameter Symbol Pin No. t 10. Output Block Dead time [Drive] t 11. Threshold V Overvoltage voltage Detection Comparator Input bias I Block current [OVP] 12. Power supply I CC General current (VCC Conditions RT 10 ...

  • Page 10

    MB3882 TYPICAL CHARACTERISTICS Supply Current vs. Supply Voltage 15.0 12.5 10.0 7.5 5.0 2.5 0 Supply voltage V Reference Voltage vs. Ambient Temperature 2.0 1.5 1.0 0.5 0.0 0.5 1.0 1.5 2 Ambient ...

  • Page 11

    Triangular Wave Oscillator Frequency vs. Timing Capacitor VCC CTL 100 100 1000 10000 Timing capacitor C (pF) T Triangular Wave Oscillator Frequency vs. Supply Voltage 250 Ta 240 ...

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    MB3882 (Continued) 12 Power Dissipation vs. Ambient Temperature 800 740 700 600 500 400 300 200 100 Ambient temperature 100 ...

  • Page 13

    FUNCTION DESCRIPTION 1. DC/DC Converter Function (1) Reference Voltage Block The reference voltage circuit takes the voltage feed from the power supply terminal (pin 23) and generates a temperature compensated reference voltage (2.5 V typ.) , for use as the ...

  • Page 14

    MB3882 2. Channel Control Functions Channel ON/OFF control is provided by using the CS1 terminal (pin 4) and CS2 terminal (pin 21) setting functions. CS terminal voltage level CS1 GND GND Hi-Z Hi-Z 3. Protective Functions (1) Timer Latch Short ...

  • Page 15

    SETTING THE TIMER LATCH SHORT CIRCUIT PROTECTOR TIME CONSTANT Each channel has a short circuit protection comparator (SCP Comp.) which constantly compares the error Amp. output level to the reference voltage. When the DC/DC comparator load conditions are stable on ...

  • Page 16

    MB3882 FB1 6 5 INE1 4 CS1 FB2 19 20 INE2 21 CS2 CSCP 22 C SCP Q1 Q4 Timer Latch Short Circuit Protection Circuit 16 Error Amp.1 ...

  • Page 17

    PROCESSING WITHOUT USING THE CSCP TERMINAL When the timer latch short circuit protection circuit is not used, the CSCP terminal (pin 22) should be shorted to GND using the shortest possible connection. Operation Without Using the CSCP Terminal 3 GND ...

  • Page 18

    MB3882 SOFT START TIME SETTING The soft start function prevents rush current events when the IC power is turned on, by connecting soft start capacitors ( the CS1 terminal (pin 4) for channel 1, and the ...

  • Page 19

    VREF (FB2) 19 FB1 6 Error ( INE2) 20 Amp. 5 INE1 21 (CS2) 4 CS1 1. (Q3) Soft Start Block MB3882 UVLO 19 ...

  • Page 20

    MB3882 PROCESSING WITHOUT USING THE CS TERIMNALS When the soft start function is not used, the CS1 terminal (pin 4) and CS2 terminal (pin 22) should be left open. "Open" OSCILLATOR FREQUENCY SETTING The oscillator frequency can be set by ...

  • Page 21

    OVERVOLTAGE PROTECTION CIRCUIT VOTAGE SETTING Overvoltage conditions in the DC/DC converter output voltage can be detected by connecting external resistance from the DC/DC converter output voltage to the INC1 terminal (pin 7) and INC2 terminal (pin 18) on the respective ...

  • Page 22

    MB3882 PRECAUTIONS RELATED TO INTERNAL IC POWER CONSUMPTION The internal power dissipation in the IC is greatly affected by the oscillator frequency and the FET total gate charge. When using the MB 3882 in an application, caution must be taken ...

  • Page 23

    Vin VCC Drive 1-1 Drive 2-1 VOUT1-1 VOUT2 Using the above formulas to determine power consumption, settings should be made with reference to the “Power Consumption vs. Input Voltage” on the following page, ...

  • Page 24

    MB3882 Power Consumption vs. Input Voltage (Qg Parameters) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 Power Consumption vs. Input Voltage (fosc Parameters) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0. ...

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    APPLICATION CIRCUIT MB3882 25 ...

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    MB3882 COMPONENT LIST COMPONENT ITEM FET D1, D2 Diode D3, D4 Diode L1, L2 Coil C1 Ceramics Condenser C2 Ceramics Condenser C3 Ceramics Condenser C4 Ceramics Condenser C5 Ceramics Condenser C6, C7 Ceramics Condenser C8 Electrolytic Condenser ...

  • Page 27

    REFERENCE DATA Conversion Efficiency vs. Load Current Characteristics (Channel 1) 100 output SW1 OFF SW2 Load current IL ...

  • Page 28

    ... Persons handling semiconductors should be grounded directly with resistance of 250 k • Do not apply negative voltages. • Application of negative voltage of 0 greater can create parasitic transistor effects on an LSI device, leading to abnormal operation. ORDERING INFORMATION Part Number MB3882PFV 28 Package Plastic SSOP 24-pin (FPT-24P-M03 ...

  • Page 29

    PACKAGE DIMENSION 24-pin, Plastic SSOP (FPT-24P-M03) * 7.75±0.10(.305±.004) INDEX 0.65±0.12(.0256±.0047) 7.15(.281)REF 2000 FUJITSU LIMITED F24018S-2C Dimensions include resin remainder. +0.20 1.25 Ð0.10 (Mounted height) +.008 .049 Ð.004 0.10(.004) * 5.60±0.10 7.60±0.20 6.60(.260) (.220±.004) (.299±.008) NOM "A" +0.10 +0.05 ...

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    MB3882 FUJITSU LIMITED For further information please contact: Japan FUJITSU LIMITED Corporate Global Business Support Division Electronic Devices KAWASAKI PLANT, 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa 211-8588, Japan Tel: +81-44-754-3763 Fax: +81-44-754-3329 http://www.fujitsu.co.jp/ North and South America FUJITSU MICROELECTRONICS, INC. 3545 ...