Fujitsu MB39A104 Datasheet

2-ch dc/dc converter ic with overcurrent protection

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FUJITSU MICROELECTRONICS

DATA SHEET

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 µA (Typ)

• Built-in soft-start circuit independent of loads

• Built-in totem-pole type output for P-ch MOS FET

• One type of package (SSOP-24 pin : 1 type)

■ APPLICATION

• LCD monitor/panel

• IP phone

• Printer

• Video capture

2006.8

etc.

DS04-27231-5Ea

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Summary of Contents for Fujitsu MB39A104

Page 1 • Built-in totem-pole type output for P-ch MOS FET • One type of package (SSOP-24 pin : 1 type) ■ APPLICATION • LCD monitor/panel • IP phone • Printer • Video capture etc. Copyright©2002-2008 FUJITSU MICROELECTRONICS LIMITED All rights reserved 2006.8...
Page 2: Table Of Contents
MB39A104 ■ PIN ASSIGNMENTS (TOP VIEW) VCCO : : CTL VH : : GNDO OUT1 : : OUT2 VS1 : : VS2 ILIM1 : : ILIM2 DTC1 : : DTC2 VCC : : GND CSCP : : VREF FB1 : : FB2 −INE1 : : −INE2...
Page 3: Vcco
MB39A104 ■ PIN DESCRIPTION Pin No. Symbol Descriptions ⎯ VCCO Output circuit power supply terminal (Connect to same potential as VCC pin) Power supply terminal for FET drive circuit (VH = V − 5 V) OUT1 External P-ch MOS FET gate drive terminal Overcurrent protection circuit input terminal Overcurrent protection circuit detection resistor connection terminal.
Page 4: Block Diagram
MB39A104 ■ BLOCK DIAGRAM −INE1 VCCO L priority VREF Error 10 µA Amp1 Comp.1 Drive1 P-ch OUT1 1.24 V L priority = 200 mA at VCCO = 12 V Current Protection ILIM1 Logic DTC1 −INE2 L priority VREF Error 10 µA Amp2 Comp.2 Drive2...
Page 5: Out1
MB39A104 ■ ABSOLUTE MAXIMUM RATINGS Rating Parameter Symbol Condition Unit ⎯ Power supply voltage VCC, VCCO terminal ⎯ Output current OUT1, OUT2 terminal Duty ≤ 5% (t = 1/f ×Duty) ⎯ Output peak current Ta ≤ +25 °C ⎯ Power dissipation 740* ⎯...
Page 6: Electrical Characteristics
MB39A104 ■ ELECTRICAL CHARACTERISTICS (VCC = VCCO = 12 V, VREF = 0 mA, Ta = +25 °C) Value Parameter Pin No Conditions Unit Symbol Ta = +25 °C Output voltage 4.95 5.00 5.05 Output voltage ∆V Ta = 0 °C to +85 °C ⎯...
Page 7: Ilim1
MB39A104 (Continued) (VCC = VCCO = 12 V, VREF = 0 mA, Ta = +25 °C) Value Parameter Symbol Pin No. Conditions Unit Frequency = 0 dB ⎯ ⎯ 9, 16 1.6* bandwidth ⎯ ⎯ 9, 16 Output voltage ⎯ ⎯...
Page 8: Typical Characteristics
MB39A104 ■ TYPICAL CHARACTERISTICS Power Supply Current vs. Power Supply Voltage Reference Voltage vs. Power Supply Voltage Ta = +25 °C Ta = +25 °C CTL = 5 V CTL = 5 V VREF = 0 mA Power supply voltage V Power supply voltage V Reference Voltage vs.
Page 9 MB39A104 Triangular Wave Oscillation Frequency Triangular Wave Oscillation Frequency vs. Timing Capacitor vs. Timing Resistor 10000 10000 Ta = +25 °C Ta = +25 °C VCC = 12 V VCC = 12 V CTL = 5 V CTL = 5 V 1000 1000 = 11 kΩ...
Page 10 MB39A104 (Continued) Error Amplifier, Gain, Phase vs. Frequency Ta = +25 °C VCC = 12 V 240 kΩ ϕ 10 kΩ 1 µF (15) − 2.4 kΩ −10 (16) 10 kΩ (14) −20 −90 Error Amp1 (Error Amp2) −30 1.24 V −40 −180 10 k...
Page 11 MB39A104 ■ FUNCTIONS 1. DC/DC Converter Functions (1) Reference voltage block (REF) The reference voltage circuit generates a temperature-compensated reference voltage (5.0 V Typ) from the voltage supplied from the VCC terminal (pin 7). The voltage is used as the reference voltage for the IC’s internal circuitry.
Page 12: Cscp
MB39A104 2. Control Function When CTL terminal (pin 24) is “L” level, IC becomes the standby mode. The power supply current is 10 µA (Max) at the standby mode. On/Off Setting Conditions Power OFF (Standby) ON (Operating) 3. Protective Functions (1) Timer-latch overcurrent protection circuit block (OCP) The timer-latch overcurrent protection circuit is actuated upon completion of the soft-start period.
Page 13 MB39A104 ■ SETTING THE OUTPUT VOLTAGE • Output Voltage Setting Circuit (−INE2) Error Amp − 1.24 (V) = (R1 + R2) −INE1 1.24 V (CS2) ■ SETTING THE TRIANGULAR OSCILLATION FREQUENCY The triangular oscillation frequency is determined by the timing capacitor (C ) connected to the CT terminal (pin 13), and the timing resistor (R ) connected to the RT terminal (pin 12).
Page 14 MB39A104 ■ SETTING THE SOFT-START AND DISCHARGE TIMES To prevent rush currents when the IC is turned on, you can set a soft-start by connecting soft-start capacitors and C ) to the CS1 terminal (pin 11) for channel 1 and the CS2 terminal (pin 14) for channel 2, respectively. ≥...
Page 15 MB39A104 • Soft-Start Circuit VREF 10 µA −INE1 (−INE2) L priority Error Amp − CH ON/OFF signal L : ON, H : OFF (CS2) 1.24 V (FB2) UVLO...
Page 16 MB39A104 ■ TREATMENT WITHOUT USING CS TERMINAL When not using the soft-start function, open the CS1 terminal (pin 11) and the CS2 terminal (pin 14) . • Without Setting Soft-Start Time “OPEN” “OPEN”...
Page 17 MB39A104 ■ ABOUT TIMER-LATCH PROTECTION CIRCUIT 1. Setting Timer-Latch Overcurrent Protection Detection Current The overcurrent protection circuit is actuated upon completion of the soft-start period. When an overcurrent flows, the circuit detects the increase in the voltage between the FET’s drain and source using the external FET ON resistor (R ), actuates the timer circuit, and starts charging the capacitor C connected to the CSCP...
Page 18 MB39A104 Overcurrent Protection Circuit: Range of Operation When an overcurrent flow occurs, if the increased voltage between the drain and source of the FET is detected by means of the external FET (Q1) resistor, operational stability is lost when the external FET (Q1) ON interval determined by the oscillation frequency, input voltage, and output voltage falls below 450 ns.
Page 19 MB39A104 2. Setting Time Constant for Timer-Latch Short-Circuit Protection Circuit Each channel uses the short-circuit detection comparator (SCP Comp.) to always compare the error amplifier′s output level to the reference voltage (3.1 V Typ). While DC/DC converter load conditions are stable on all channels, the short-circuit detection comparator output remains at “L”...
Page 20 MB39A104 ■ TREATMENT WITHOUT USING CSCP TERMINAL When not using the timer-latch short-circuit protection circuit, connect the CSCP terminal (pin 8) to GND with the shortest distance. Treatment without using CSCP • CSCP ■ RESETTING THE LATCH OF EACH PROTECTION CIRCUIT When the overcurrent, or short-circuit protection circuit detects each abnormality, it sets the latch to fix the output at the "L"...
Page 21 MB39A104 ■ I/O EQUIVALENT CIRCUIT 〈〈Reference voltage block〉〉 〈〈Control block〉〉 〈〈Soft-start block〉〉 VREF (5.0 V) protection 1.24 V kΩ element − VREF protection 77.8 kΩ element kΩ protection 24.8 kΩ element 〈〈Triangular wave oscillator 〈〈Triangular wave oscillator 〈〈Short-circuit detection block〉〉 block (RT) 〉〉...
Page 22 MB39A104 ■ APPLICATION EXAMPLE...
Page 23: Parts List
MB39A104 ■ PARTS LIST COMPONENT ITEM SPECIFICATION VENDOR PARTS No. VDS = −30 V, ID = −6 A Q1, Q2 P-ch FET TOSHIBA TPC8102 VF = 0.42 V (Max) , at IF = 3 A D1, D2 Diode ROHM RB0530L-30 15 µH L1, L2 Inductor...
Page 24 MB39A104 ■ SELECTION OF COMPONENTS • P-ch MOS FET The P-ch MOSFET for switching use should be rated for at least 20% more than the maximum input voltage. To minimize continuity loss, use a FET with low R between the drain and source. For high input voltage and DS(ON) high frequency operation, on/off-cycle switching loss will be higher so that power dissipation must be considered.
Page 25 MB39A104 × R ) × Duty × 0.05 × 0.263 : = 0.118 W ) × I × tr × f 19 × 3 × 100 × 10 × 500 × 10 −9 : = 0.475 W ) × I ) ×...
Page 26 MB39A104 × R ) × Duty × 0.05 × 0.174 : = 0.078 W ) × I × tr × f 19 × 3 × 100 × 10 × 500 × 10 −9 : = 0.475 W ) × I ) ×...
Page 27 MB39A104 Example: − V 2 (V L ≥ 2 × (19 − 5) ≥ × × 0.263 500 × 10 ≥ 4.91 µH − V 2 (V L ≥ 2 × (19 − 3.3) ≥ × × 0.174 500 × 10 ≥...
Page 28 MB39A104 To determine whether the current through the inductor is within rated values, it is necessary to determine the peak value of the ripple current as well as the peak-to-peak values of the ripple current that affect the output ripple voltage. The peak value and peak-to-peak value of the ripple current can be determined by the following formulas.
Page 29 MB39A104 • Flyback diode The flyback diode is generally used as a Shottky barrier diode (SBD) when the reverse voltage to the diode is less than 40V. The SBD has the characteristics of higher speed in terms of faster reverse recovery time, and lower forward voltage, and is ideal for achieving high efficiency.
Page 30 MB39A104 • Smoothing Capacitor The smoothing capacitor is an indispensable element for reducing ripple voltage in output. In selecting a smooth- ing capacitor it is essential to consider equivalent series resistance (ESR) and allowable ripple current. Higher ESR means higher ripple voltage, so that to reduce ripple voltage it is necessary to select a capacitor with low ESR.
Page 31 MB39A104 ∆V ESR ≤ − ∆I 2πfC 0.033 ≤ − 2π × 500 × 10 × 82 × 10 −6 0.364 ≤ 86.8 mΩ Capacitance value ∆I ≥ − ∆I × ESR) 2πf (∆V 0.491 ≥ 2π × 500 × 10 ×...
Page 32 MB39A104 ■ REFERENCE DATA vs. Load Current ( Conversion Efficiency = 7 V = 10 V = 12 V = 19 V Ta = +25 °C 5 V Output SW1 = OFF SW2 = ON 10 m 100 m Load current IL (A) vs.
Page 33 MB39A104 (Continued) Switching Wave Form (CH1) Ta = +25 °C = 12 V CTL = 5 V = 5 V RL = 1.67 Ω t (µs) Switching Wave Form (CH2) Ta = +25 °C = 12 V CTL = 5 V = 3.3 V RL = 1.1 Ω...
Page 34 ■ RoHS COMPLIANCE INFORMATION OF LEAD (Pb) FREE VERSION The LSI products of Fujitsu Microelectronics with “E1” are compliant with RoHS Directive , and has observed the standard of lead, cadmium, mercury, Hexavalent chromium, polybrominated biphenyls (PBB) , and polybro- minated diphenyl ethers (PBDE) .
Page 35 MB39A104 ■ LABELING SAMPLE (LEAD FREE VERSION) lead-free mark JEITA logo JEDEC logo MB123456P - 789 - GE1 (3N) 1MB123456P-789-GE1 1000 (3N)2 1561190005 107210 QC PASS 1,000 MB123456P - 789 - GE1 ASSEMBLED IN JAPAN 2006/03/01 MB123456P - 789 - GE1 0605 - Z01A 1000 1561190005...
Page 36 MB39A104 ■ MB39A104PFV-❏❏❏E1 RECOMMENDED CONDITIONS OF MOISTURE SENSITIVITY LEVEL Item Condition Mounting Method IR (infrared reflow) , Manual soldering (partial heating method) Mounting times 2 times Please use it within two years after Before opening Manufacture. From opening to the 2nd Storage period Less than 8 days reflow...
Page 37: Package Dimension
.049 –.004 0.25(.010) 0~8 ˚ "A" +0.08 0.65(.026) 0.24 –0.07 0.13(.005) +.003 .009 0.50±0.20 0.10±0.10 –.003 (.020±.008) (.004±.004) (Stand off) 0.60±0.15 (.024±.006) 0.10(.004) 0.10(.004) Dimensions in mm (inches). 2003 FUJITSU LIMITED F24018S-c-4-5 Note: The values in parentheses are reference values.
Page 38 MB39A104 MEMO...
Page 39 MB39A104 MEMO...
Page 40 (2) for use requiring extremely high reliability (i.e., submersible repeater and artificial satellite). Please note that FUJITSU MICROELECTRONICS will not be liable against you and/or any third party for any claims or damages arising in connection with above-mentioned uses of the products.

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