FUJITSU MICROELECTRONICS DATA SHEET DS04-27703-4Ea ASSP For Power Supply Applications (Lithium ion battery charger) DC/DC Converter IC for Charging MB3875/MB3877 DESCRIPTION The MB3875 and MB3877 are charging DC/DC converter ICs suitable for down-conversion, which uses pulse width modulation (PWM) for controlling the output voltage and current independently. These ICs can dynamically control the secondary battery's charge current by detecting a voltage drop in an AC adapter in order to keep its power constant (dynamically-controlled charging). The charging method enables quick charging, for example, with the AC adapter during operation of a notebook PC. With an on-chip output voltage setting resistor which allows the output voltage to be set at high precision, these ICs are best suited as internal battery chargers for notebook PCs. The MB3875 and MB3877 support 3-cell and 4-cell batteries, respectively. These products are covered by US Patent Number 6,147,477. FEATURES * Detecting a voltage drop in the AC adapter and dynamically controlling the charge current (Dynamically-controlled charging) * High efficiency : 95 % * Wide range of operating supply voltages: 7 V to 25 V * Output voltage precision (Output voltage setting resistor integrated): 0 0.8 % (Ta = + 25 C) (Continued) PACKAGE 24-pin plastic SSOP (FPT-24P-M03) Copyright(c)2003-2008 FUJITSU MICROELECTRONICS LIMITED All rights reserved 2003.8 MB3875/3877 (Continued) * High precision reference voltage source: 4.2 V 0.8 % * Support for frequency setting using an external resistor (Frequency setting capacitor integrated) :100 kHz to 500 kHz * On-chip current detector amplifier with wide in-phase input voltage range : 0 V to VCC * On-chip standby current function: 0 A (Typ) * On-chip soft-start function * Internal totem-pole output stage supporting P-channel MOS FETs devices PIN ASSIGNMENT (TOP VIEW) 24 : +INC2 -INC2 : 1 IN3 : 2 23 : GND FB2 : 3 22 : CS 21 : VCC (O) OUTC2 : 4 VREF : 5 20 : OUT -INE2 : 6 19 : VH +INE2 : 7 18 : VCC +INE1 : 8 17 : RT 16 : -INE3 FB1 : 9 OUTC1 : 10 15 : FB3 -INE1 : 11 14 : CTL -INC1 : 12 13 : +INC1 (FPT-24P-M03) 2 MB3875/3877 PIN DESCRIPTION Pin No. Symbol I/O Descriptions 1 -INC2 I Current detection amplifier (Current Amp. 2) input pin. 2 IN3 I DC/DC output voltage (charge voltage) input pin. 3 FB2 O Error amplifier (Error Amp. 2) output pin. 4 OUTC2 O Current detection amplifier (Current Amp. 2) output pin. 5 VREF O Reference voltage output pin. 6 -INE2 I Error amplifier (Error Amp. 2) inverted input pin. 7 +INE2 I Error amplifier (Error Amp. 2) non-inverted input pin. 8 +INE1 I Error amplifier (Error Amp. 1) non-inverted input pin 9 FB1 O Error amplifier (Error Amp. 1) output pin. 10 OUTC1 O Current detection amplifier (Current Amp. 1) output pin. 11 -INE1 I Error amplifier (Error Amp. 1) inverted input pin. 12 -INC1 I Current detection amplifier (Current Amp. 1) input pin. 13 +INC1 I Current detection amplifier (Current Amp. 1) input pin. 14 CTL I Power supply control pin. Setting the CTL pin low places the IC in the standby mode. 15 FB3 O Error amplifier (Error Amp. 3) output pin. 16 -INE3 I Error amplifier (Error Amp. 3) inverted input pin. 17 RT -- Triangular-wave oscillation frequency setting resistor connection pin. 18 VCC -- Power supply pin for reference power supply and control circuit. 19 VH O Power supply pin for FET drive circuit (VH = Vcc - 5 V). 20 OUT O High-side FET gate drive pin. 21 VCC(O) -- Output circuit power supply. 22 CS -- Soft-start capacitor connection pin. 23 GND -- Ground pin. 24 +INC2 I Current detection amplifier (Current Amp. 2) input pin. 3 MB3875/3877 BLOCK DIAGRAM -INE1 11 OUTC1 10 <Current Amp.1> + x 25 -INC1 - 12 +INC1 +INE1 FB1 -INE2 OUTC2 +INC2 -INC2 +INE2 FB2 IN3 13 <Error Amp.1> VREF - + 8 <PWM Comp.> + + + - 9 6 4 24 1 <Current Amp.2> + x 25 - <Error Amp.2> VREF - <OUT> OUT Drive 20 VCC Bias voltage block + 7 19 VH (VCC - 5 V) <VH> 3 2 <UVLO> -INE3 VCC (O) 21 R1 16 R2 50 k <Error Amp.3> VREF (VCC UVLO) 215 k + - + + 15 35 k - 0.91 V (0.77 V) VREF (4.2 V) FB3 VCC VREF ULVO <SOFT> VREF 1 A VCC CS 22 bias 2.5 V 1.5 V CTL <OSC> <REF> <CTL> (45 pF) RT 17 VREF 5 GND 23 : MB3875 100 k MB3877 150 k 4 VCC 18 14 MB3875/3877 ABSOLUTE MAXIMUM RAGINGS Parameter Symbol Rating Conditions Unit Min Max -- 28 V Power supply voltage VCC Output current IOUT -- -- 60 mA Peak output current IOUT Duty 5% (t =1 / fOSC x Duty) -- 500 mA Power dissipation PD Ta +25C -- 740* mW -55 +125 C Storage temperature VCC,VCC(O) Tstg -- *: The package is mounted on the dual-sided epoxy board (10 cm x 10 cm). 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. RECOMMENDED OPERATING CONDITIONS Parameter Symbol Conditions Value Unit Min Typ Max 7 -- 25 V Power supply voltage VCC Reference voltage output current IREF -- -1 -- 0 mA VH pin output current IVH -- 0 -- 30 mA VCC,VCC(O) VIN IN3 0 -- 17 V VINE -INE1,-INE2,+INE1,+INE2 0 -- VCC - 1.8 V VINC +INC1,+INC2,-INC1,-INC2, 0 -- VCC V CTL pin input voltage VCTL -- 0 -- 25 V Output current IOUT -- -45 -- 45 mA Peak output current IOUT Duty 5% (t =1 / fOSC x Duty) -450 -- 450 mA Oscillator frequency fOSC -- 100 290 500 kHz Timing resistor RT -- 33 47 130 k Soft-start capacitor CS -- -- 2200 100000 pF VH pin capacitor CVH -- -- 0.1 1.0 F Reference voltage output capacitor CREF -- -- 0.1 1.0 F Operating temperature Ta -- -30 +25 +85 C Input voltage WARNING: The recommended operating conditions are required in order to ensure the normal operation of the semiconductor device. All of the device's electrical characteristics are warranted when the device is operated within these ranges. Always use semiconductor devices within their recommended operating condition ranges. Operation outside these ranges may adversely affect reliability and could result in device failure. No warranty is made with respect to uses, operating conditions, or combinations not represented on the data sheet. Users considering application outside the listed conditions are advised to contact their representatives beforehand. 5 MB3875/3877 ELECTRICAL CHARACTERISTICS (MB3875: Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Reference voltage block (Ref) Parameter Symbol Pin No. Unit Remarks Min Typ Max Ta = +25C 4.167 4.200 4.233 V Ta = -30C to +85C 4.158 4.200 4.242 V VREF 5 Input stability Line 5 VCC = 7 V to 25 V -- 3 10 mV Load stability Load 5 VREF = 0 mA to -1 mA -- 1 10 mV Short-circuit output current IOS 5 VREF = 1 V -25 -15 -5 mA VCC =VCC (O), VCC = 6.3 6.6 6.9 V VCC =VCC (O), VCC = 5.3 5.6 5.9 V VCC =VCC (O) 0.7 1.0 1.3 V VREF = 2.6 2.8 3.0 V VREF= 2.4 2.6 2.8 V Threshold voltage 18 VTHL Under voltage lockout protection circuit block (UVLO) Value Output voltage VTLH Triangular waveform Soft-start block oscillator circuit (SOFT) block (OSC) Conditions Hysteresis width VH 18 VTLH Threshold voltage 5 VTHL Hysteresis width VH 5 -- 0.05 0.20 0.35 V Charge current ICS 22 -- -1.3 -0.8 -0.5 A Oscillation frequency fOSC 20 RT = 47 k 260 290 320 kHz Frequency temperature stability f/fdT 20 Ta = -30C to +85C -- 1* -- % *: Standard design value. (Continued) 6 MB3875/3877 (MB3875: Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Symbol Pin No Input offset voltage Error amplifier block (Error Amp.1, 2) Input bias current VIO 6,7,8,11 FB1 = FB2 = 2 V Value Unit Remarks Min Typ Max -- 1 5 mV IB 6,7,8,11 -- -100 -30 -- nA Common mode input voltage range VCM 6,7,8,11 -- 0 -- VCC-1.8 V Voltage gain AV 3,9 DC -- 100* -- dB Frequency bandwidth BW 3,9 AV = 0 dB -- 2.0* -- MHz VFBH 3,9 -- 3.9 4.1 -- V VFBL 3,9 -- -- 20 200 mV ISOURCE 3,9 FB1 = FB2 = 2 V -- -2.0 -0.6 mA ISINK 3,9 FB1 = FB2 = 2 V 150 300 -- A Output voltage Output source current Output sink current Threshold voltage VTH FB3 = 2 V, Ta = +25 C 12.500 12.600 12.700 V MB3875 16.666 16.800 16.934 V MB3877 FB3 = 2 V, Ta = -30 C to +85 C 12.474 12.600 12.726 V MB3875 16.632 16.800 16.968 V MB3877 2 IN3 = 12.6 V -- 84 150 A MB3875 IN3 = 16.8 V -- 84 150 A MB3877 VCC = 0 V, IN3 = 12.6 V -- 0 1 A MB3875 VCC = 0 V, IN3 = 16.8 V -- 0 1 A MB3877 70 100 130 k MB3875 105 150 195 k MB3877 35 50 65 k DC -- 100* -- dB AV = 0 dB -- 2.0* -- MHz -- 3.9 4.1 -- V -- -- 20 200 mV FB3 = 2 V -- -2.0 -0.6 mA FB3 = 2 V 150 300 -- A IINE3H 2 IINE3L 2 R1 2 -- R2 16 -- Voltage gain AV 15 Frequency bandwidth BW 15 VFBH 15 VFBL 15 ISOURCE 15 ISINK 15 Input current Error amplifier block (Error Amp.3) Conditions Input resistor Output voltage Output source current Output sink current *: Standard design value. (Continued) 7 MB3875/3877 (MB3875: Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Symbol Pin No. I+INCH Input current I-INCH Current detection amplifier block (Current Amp.1,2) Common mode input voltage range Voltage gain Frequency bandwidth Output voltage Output source current Output sink current 1, 12 Value Unit Remarks Min Typ Max +INC1= +INC2=12.7 V -INC1= -INC2=12.6 V -- 10 20 A MB3875 +INC1= +INC2=16.9 V -INC1= -INC2=16.8 V -- 10 20 A MB3877 +INC1= +INC2=12.7 V -INC1= -INC2=12.6 V -- 0.1 0.2 A MB3875 +INC1= +INC2=16.9 V -INC1= -INC2=16.8 V -- 0.1 0.2 A MB3877 I+INCL 13, 24 +INC1= +INC2= 0.1 V -INC1= -INC2= 0 V -130 -65 -- A I-INCL 1, 12 +INC1= +INC2= 0.1V -INC1= -INC2= 0 V -140 -70 -- A +INC1= +INC2=12.7 V -INC1= -INC2=12.6 V 2.25 2.5 2.75 V MB3875 +INC1= +INC2=16.9 V -INC1= -INC2=16.8 V 2.25 2.5 2.75 V MB3877 +INC1= +INC2=12.63V -INC1= -INC2=12.6 V 0.50 0.75 1.00 V MB3875 +INC1= +INC2=16.83V -INC1= -INC2=16.8 V 0.50 0.75 1.00 V MB3877 VOUTC1 Current detection voltage 13, 24 Conditions VOUTC2 4, 10 4, 10 VOUTC3 4, 10 +INC1= +INC2= 0.1 V -INC1= -INC2= 0 V 1.25 2.50 3.75 V VOUTC4 4, 10 +INC1= +INC2= 0.03 V -INC1= -INC2= 0 V 0.125 0.750 1.375 V VCM 1, 12, 13, 24 -- 0 -- VCC V +INC1= +INC2=12.7 V -INC1= -INC2=12.6 V 22.5 25 27.5 V/V MB3875 +INC1= +INC2=16.9 V -INC1= -INC2=16.8 V 22.5 25 27.5 V/V MB3877 -- 2.0* -- AV 4, 10 BW 4, 10 AV = 0 dB VOUTCH 4, 10 -- 3.9 4.1 VOUTCL 4, 10 -- -- 20 200 mV ISOURCE 4, 10 OUTC1 = OUTC2 = 2 V -- -2.0 -0.6 mA ISINK 4, 10 OUTC1 = OUTC2 = 2 V 150 300 -- A MHz V *: Standard design value. (Continued) 8 MB3875/3877 (Continued) (MB3875 : Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0mA) (MB3877 : Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0mA) PWM comparator block (PWM Comp.) Parameter Symbol Pin No. Conditions Output block (OUT) Typ Max Unit Remarks VTL 3,9,15 Duty cycle = 0 % 1.4 1.5 -- V VTH 3,9,15 Duty cycle = 100 % -- 2.5 2.6 V OUT = 11 V Duty 5 % -- -200* -- mA MB3875 OUT = 14 V Duty 5 % -- -200* -- mA MB3877 OUT = 16 V Duty 5 % -- 200* -- mA MB3875 OUT = 19 V Duty 5 % -- 200* -- mA MB3877 ISOURCE 20 (t = 1/fosc x Duty ) (t = 1/fosc x Duty ) Output sink current ISINK 20 (t = 1/fosc x Duty ) (t = 1/fosc x Duty ) ROH 20 OUT = -45 mA -- 8.0 16 ROL 20 OUT = 45 mA -- 6.5 13 Rise time tr1 20 -- 70* -- ns Fall time tf2 20 -- 60* -- ns VON 14 Active mode 2 -- 25 V VOFF 14 Standby mode 0 -- 0.8 V ICTLH 14 CTL = 5 V -- 100 200 A ICTLL 14 CTL = 0 V -- 0 1 A Output voltage VH 19 VCC = VCC(O) = 7 V to 25 V, VH = 0 to 30 mA Standby current ICCS 18 VCC = VCC(O), CTL = 0 V Power supply current ICC 18 VCC = VCC(O), CTL = 5 V Output ON resistor Bias Control block voltage (CTL) block (VH) Min Threshold voltage Output source current General Value CTL input voltage Input current OUT = 3300 pF (Equivalent to Si4435DY) OUT = 3300 pF (Equivalent to Si4435DY) VCC-5.5 VCC-5.0 VCC-4.5 V -- 0 10 A -- 6.0 9.0 mA MB3875 -- 6.5 9.5 mA MB3877 *: Standard design value. 9 MB3875/3877 TYPICAL CHARACTERISTICS 10 Reference voltage vs. power supply voltage 10 Ta = +25 C CTL = 5 V Reference voltage VREF (V) Power supply current ICC (mA) Power supply current vs. power supply voltage 8 6 4 2 0 0 5 10 15 20 Ta = +25 C CTL = 5 V VREF = 0 mA 8 6 4 2 0 25 0 Reference voltage VREF (%) Reference voltage VREF (V) Ta = +25 C VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V 6 4 2 0 0 5 10 15 20 25 2.0 1.0 0.0 -0.5 -1.0 -1.5 -2.0 -40 30 -20 0 20 40 60 80 100 Ambient temperature Ta (C) CTL pin current vs. CTL pin voltage 10 Ta = +25 C VCC = 16 V (MB3875) VCC = 19 V (MB3877) VREF = 0 mA CTL pin current ICTL (A) Reference voltage VREF (V) 25 0.5 Reference voltage vs. CTL pin voltage 8 20 VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V VREF = 0 mA 1.5 VREF load current IREF (mA) 10 15 Reference voltage vs. ambient temperature Reference voltage vs. VREF load current 8 10 Power supply voltage VCC (V) Power supply voltage VCC (V) 10 5 6 4 2 Ta = +25 C VCC = 16 V (MB3875) VCC = 19 V (MB3877) 8 6 4 2 0 0 0 5 10 15 CTL pin voltage VCTL(V) 20 25 0 5 10 15 20 25 Control pin voltage VCTL (V) (Continued) 10 MB3875/3877 Triangular wave oscillator frequency vs. timing resistor 1M Ta = +25 C VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V 100 k 10 k 10 k 100 k 1M Timing resistor RT () Triangular wave oscillator frequency fOSC(kHz) Triangular wave oscillator frequency fOSC(Hz) (Continued) 350 VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V RT = 47 k 340 330 320 310 300 290 280 270 260 250 -40 -20 0 20 40 60 Ambient temperature Ta (C) 80 100 350 Ta = +25 C CTL = 5 V RT = 47 k 340 330 320 310 300 290 280 270 260 250 0 5 10 15 20 25 Power supply voltage VCC (V) Error amplifier threshold voltage vs. ambient temperature Error amplifier threshold voltage VTH(%) Triangular wave oscillator frequency fOSC(kHz) Triangular wave oscillator frequency vs. ambient temperature Triangular wave oscillator frequency vs. power supply voltage 5.0 VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V 4.0 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 -40 -20 0 20 40 60 80 100 Ambient temperature Ta (C) 11 MB3875/3877 (Continued) Error amplifier gain and phase vs. frequency Ta = +25 C AV 4.2 V 20 VCC = 16 V (MB3875) VCC = 19 V (MB3877) 180 90 Phase (deg) Gain AV (dB) 40 0 0 -20 -90 -40 -180 100 1k 10 k 100 k 1M 240 k IN - + 10 k 2.4 k 10 k - 11 (6) 8 + (7) 2.088 V OUT 9 (3) 10 M Frequency f (Hz) Current detection amplifier gain and phase vs. frequency Ta = +25 C 40 VCC = 16 V (MB3875) VCC = 19 V (MB3877) 180 20 90 0 0 -20 -90 -40 -180 100 1k 10 k 100 k Phase (deg) Gain AV (dB) AV 1M Frequency f (Hz) Power dissipation PD (mW) Power dissipation vs. ambient temperature 800 740 700 600 500 400 300 200 100 0 -40 -20 0 20 40 60 Ambient temperature Ta (C) 12 80 100 24 (13) 0.1 V 1 (12) + x 25 - 100 k 4 (10) Current Amp.2 (Current Amp.1) : MB3875 12.6 V MB3877 16.8 V OUT MB3875/3877 FUNCTIONAL DESCRIPTION 1. DC/DC Converter Unit (1) Reference voltage block (Ref) The reference voltage generator uses the voltage supplied from the Vcc terminal (pin 18) to generate a temperature-compensated, stable voltage ( =: 4.2 V) used as the reference supply voltage for the IC's internal circuitry. The reference voltage can be output, up to 1 mA, to an external device through the VREF terminal (pin 5). (2) Triangular wave oscillator block(OSC) The triangular wave oscillator generates a triangular waveform with a frequency setting resistor connected to the internal frequency setting capacitor via the RT terminal (pin 17). The triangular wave is input to the PWM comparator on the IC. (3) Error amplifier block (Error Amp. 1) This error amplifier (Error Amp. 1) detects a voltage drop in the AC adapter and outputs a PWM control signal. In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB1 terminal (pin 9) to the -INE1 terminal (pin 11) of the error amplifier, enabling stable phase compensation to the system. (4) Error amplifier block (Error Amp. 2) This error amplifier (Error Amp. 2) detects the output signal from the current detector amplifier (Current Amp. 2), compares it with the +INE2 terminal (pin 7), and outputs a PWM control signal to control the charge current. In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB2 terminal (pin 3) to the -INE2 terminal (pin 6) of the error amplifier, enabling stable phase compensation to the system. (5) Error amplifier block (Error Amp. 3) This error amplifier (Error Amp. 3) detects the output voltage from the DC/DC converter and outputs the PWM control signal. The error amplifier inverting input pin is connected to the output voltage setting resistor in the IC, eliminating the need for an external resistor for setting the output voltage. The MB3875 and MB3877 are set to output voltage of 12.6 V (for a 3-cell battery) and 16.8 V (for a 4-cell battery), respectively; these ICs are suitable for use in equipment that uses a lithium-ion battery. In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB3 terminal (pin 15) to the -INE3 terminal (pin 16) of the error amplifier, enabling stable phase compensation to the system. Connecting a soft-start capacitor to the CS terminal (pin 22) prevents surge currents when the IC is turned on. Using an error amplifier for soft-start detection makes the soft-start time constant, independent of the output load. (6) Current detector amplifier block (Current Amp. 2) The current detection amplifier (Current Amp. 2) detects a voltage drop which occurs between both ends of the output sense resistor (RS) due to the flow of the charge current, using the +INC2 terminal (pin 24) and -INC2 terminal (pin 1). Then it outputs the signal amplified by 25 times to the error amplifier (Error Amp. 2) at the next stage. 13 MB3875/3877 (7) PWM comparator block (PWM Comp.) The PWM comparator circuit is a voltage-pulse width converter for controlling the output duty of the error amplifiers (Error Amp. 1 to Error Amp. 3) depending on their output voltage. The PWM comparator circuit compares the triangular wave generated by the triangular wave oscillator to the error amplifier output voltage and turns on the external output transistor during the interval in which the triangular wave voltage is lower than the error amplifier output voltage. (8) Output block (OUT) The output circuit uses a totem-pole configuration capable of driving an external P-channel MOS FET. The output "L" level sets the output amplitude to 5 V (typical) using the voltage generated by the bias voltage block (VH). This results in increasing conversion efficiency and suppressing the withstand voltage of the connected external transistor in a wide range of input voltages. (9) Control block (CTL) Setting the CTL terminal (pin 14) low places the IC in the standby mode. (The supply current is 10 A at maximum in the standby mode.) (10) Bias voltage block (VH) The bias voltage circuit outputs Vcc - 5 V (typical) as the minimum potential of the output circuit. In the standby mode, this circuit outputs the potential equal to Vcc. 2. Protection Functions Low-Vcc malfunction preventive circuit (UVLO) The transient state or a momentary decrease in supply voltage or internal reference voltage (VREF), which occurs when the power supply is turned on, may cause malfunctions in the control IC, resulting in breakdown or degradation of the system. To prevent such malfunction, the low-Vcc malfunction preventive circuit detects a supply voltage or internal reference voltage drop and fixes the OUT terminal (pin 20) to the "H" level. The system restores voltage supply when the supply voltage or internal reference voltage reaches the threshold voltage of the low-Vcc malfunction preventive circuit. 3. Soft-Start Function Soft-start block (SOFT) Connecting a capacitor to the CS terminal (pin 22) prevents surge currents when the IC is turned on. Using an error amplifier for soft-start detection makes the soft-start time constant, independent of the output load of the DC/DC converter. 14 MB3875/3877 METHOD OF SETTING THE CHARGING CURRENT The charge current (output control current) value can be set with the voltage at the +INE2 terminal. If a current exceeding the set value attempts to flow, the charge voltage drops according to the set current value. Battery charge current setting voltage +INE2 (V) = 25 x I1 (A) x RS () METHOD OF SETTING THE SOFT-START TIME Upon activation, the IC starts charging the capacitor (Cs) connected to the CS terminal (pin 22). The error amplifier causes soft-start operation to be performed with the output voltage in proportion to the CS pin voltage regardless of the load current of the DC/DC converter. Soft-start time ts (Time taken for the output voltage to reach 100 %) ts (s) =: 4.2 x CS (F) METHOD OF SETTING THE TRIANGULAR WAVE OSCILLATOR FREQUENCY SETTING The trianguar wave oscillator frequency can be set by the timing resistor (RT) connected the RT terminal (pin 17). Triangular wave oscillator frequency fOSC fOSC (kHz) =: 14444 / RT (k) 15 MB3875/3877 AC ADAPTER VOLTAGE DETECTION With an external resistor connected to the +INE1 terminal, the IC enters the dynamically-controlled charging mode to reduce the charge current to keep AC adapter power constant when the partial potential point A of the AC adapter voltage (Vcc) becomes lower than the voltage at the -INE1 terminal. AC adapter detected voltage setting Vth Vth (V) = (R1 + R2) / R2 x - INE1 - INE1 setting voltage range : 1.176 V to 4.2 V (equivalent to 7 V to 25 V for Vcc) <Error Amp.1> -INE1 A VCC R1 +INE1 11 - 8 + R2 OPERATION TIMING DIAGRAM 2.5 V Error Amp.2 FB2 Error Amp.3 FB3 Error Amp.1 FB1 1.5 V OUT AC adapter dynamicallycontrolled charging 16 Constant voltage control Constant current control AC adapter dynamicallycontrolled charging MB3875/3877 NOTE ON AN EXTERNAL REVERSE-CURRENTPREVENTIVE DIODE Insert a reverse-current preventive diode (D) at one of the three locations marked * to prevent reverse current from the battery. Pay attention to the voltage/current characteristics of the reverse-current preventive diode (D) not to let it exceed the overcharge stop voltage. 21 VCC(O) VIN (16 V/19 V) D A B OUT 20 D I1 BATT RS 12.6 V/16.8 V 19 VH D Battery 1 17 MB3875/3877 APPLICATION EXAMPLE R5 330 k R6 68 k FB1 150 k R7 R12 22 k R14 1.3 k Q2 <PWM Comp.> + + + - 6 4 <Current Amp.2> +INC2 + A 24 x 25 -INC2 - B 1 +INE2 FB2 110 R15 IN3 SW1 + C5 0.1 F C1 22 F <OUT> A OUT Drive Q1 L1 20 B RS Bias voltage block + <VH> 19 VH + + - - D1 (VCC - 5 V) 3 2 1 16 C6 3900 pF 200 k R3 50 k <Error Amp.3> VREF 15 VCC (VCC UVLO) 215 k + - + + 35 k - 0.91 V (0.77 V) VREF (4.2 V) FB3 VREF ULVO <SOFT> VREF 1 A VCC CS 22 bias 2.5 V 1.5 V VCC 18 CTL <OSC> <REF> <CTL> C7 0.1 F 14 (45 pF) RT RT 17 VREF 47 k 5 GND C9 0.1 F 18 BATT 4 0.033 C3 C2 100 F 100 F VCC <UVLO> CS 2200 pF - 27 H <Error Amp.2> VREF - 7 VIN 3 -INE3 VCC (O) 21 100 k OUTC2 30 k R13 R16 200 k + 9 -INE2 R8 C8 3900 pF <Error Amp.1> VREF - 23 1 : MB3875 MB3877 2 : Vin = 16 V Vin = 19 V 3 : MB3875 MB3877 4 : MB3875 MB3877 100 k 150 k 0 82 k 16 V/19 V 19 V 12.6 V 16.8 V Battery R4 2 -INE1 11 R10 22 k OUTC1 C10 3900 pF 10 <Current Amp.1> +INC1 + 13 x 25 -INC1 R11 - 12 30 k 150 k R9 8 +INE1 MB3875/3877 PARTS LIST COMPONET ITEM SPECIFICATION VENDOR PARTS NO. QI Q2 FET FET Si4435DY 2N7002 VISHAY SILICONIX VISHAY SILICONIX Si4435DY 2N7002 D1 Diode MBRS130LT3 MOTOROLA MBRS130LT3 L1 Coil 27H 3.4A, 34m SUMIDA CDRH127-27uH C1 C2 OS Condensor OS Condensor 22F 100F C3 OS Condensor 100F CS C5 C6 C7 C8 C9 C10 Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor 2200pF 0.1F 3900pF 0.1pF 3900pF 0.1F 3900pF 25V(10%) 16V(10%) 25V(10%) 16V(10%) 25V(10%) 10% 16V 10% 25V 10% 16V 10% -- -- RS RT R3 R4 Resistor Resistor Resistor Resistor R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor 0.033 47k 200k 0 82k 330k 68k 150k 100k 150k 22k 30k 22k 30k 1.3k 110 200k 1.0% 1.0% 1.0% Jumper line 0.5% 0.5% 0.5% 1.0% 1.0% 1.0% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 5% -- -- Note: VISHAY SILICONIX : VISHAY Intertechrology, Inc. MOTOROLA : Motorola Japan Ltd. SUMIDA : SUMIDA ELECTRIC CO., Ltd. 19 MB3875/3877 REFERENCE DATA * MB3875 Conversion efficiency vs. charge voltage (Fixed current mode) Conversion efficiency vs. charge current (Fixed voltage mode) 100 BATT charge voltage=12.6V fOSC=288.78kHz efficiency (%)=(VBATT x IBATT)/(Vin x Iin) x 100 98 96 Conversion efficiency (%) Conversion efficiency (%) 100 Vin = 16 V 94 92 Vin = 19 V 90 88 86 84 82 80 10 m 100 m 1 94 90 Vin = 19 V R4 = 82 k 88 86 84 82 80 0 2 4 6 8 10 12 14 16 10 BATT charge voltage VBATT(V) BATT voltage vs. BATT charge current 16 Vin=16v BATT: Electronic load 14 (Product of KIKUSUI PLZ-150W) 12 10 Dead Battery MODE DCC MODE 8 6 4 2 0 1 DCC : Dynamically-Controlled Charging 2 3 4 5 BATT charge current IBATT(A) Note: KIKUSUI : KIKUSUI Electronics Corp. BATT voltage VBATT(V) 18 18 BATT voltage VBATT(V) Vin = 16 V R4 = 0 92 BATT voltage vs. BATT charge current 20 (Product of KIKUSUI PLZ-150W) 96 BATT charge current IBATT(A) 0 BATT= Electronic load 98 16 Vin=19v BATT: Electronic load 14 (Product of KIKUSUI PLZ-150W) 12 10 Dead Battery MODE DCC MODE 8 6 4 2 0 0 1 DCC : Dynamically-Controlled Charging 2 3 4 5 BATT charge current IBATT(A) MB3875/3877 (Continued) Soft-start operating waveforms DC/DC converter switching waveforms Vin = 16 V Load: BATT = 20 - INE1 = 0 V Vin = 16 V FOSC = 288.8 kHz Load: BATT = 2A BATT (V) 20 CTL (V) 20 10 15 0 1 s 5V 5V 15 OUT (V) 20 5 15 10 10 5 5 0 0 5V 0 20 ms 40 80 120 160 -5 200 t (ms) Soft-start operating waveforms 0 10 15 0 6 8 10 t (s) Vin = 19 V FOSC = 288.8 kHz Load: BATT = 2A BATT (V) 20 CTL (V) 20 4 DC/DC converter switching waveforms Vin = 19 V Load: BATT = 20 - INE1 = 0 V 1 s 5V 5V 15 2 OUT (V) 20 5 15 10 10 5 5 0 0 5V 0 40 20 ms 80 120 160 -5 200 t (ms) 0 2 4 6 8 10 t (s) 21 MB3875/3877 * MB3877 Conversion efficiency vs.charge current BATT charge voltage=12.6V fOSC=288.78kHz efficiency (%)=(VBATT x IBATT)/(Vin x Iin) x 100 98 100 Conversion efficiency (%) Conversion efficiency (%) 100 Conversion efficiency vs. charge voltage 96 94 92 Vin = 19 V 90 88 86 84 82 80 10 m 100 m 1 10 BATT charge current IBATT(A) BATT voltage vs. BATT charge current 20 Vin=19v BATT: Electronic load BATT voltage VBATT(V) 18 16 (Product of KIKUSUI PLZ-150W) 14 12 Dead Battery MODE 10 DCC MODE 8 6 4 2 0 0 1 DCC : Dynamically-Controlled Charging 2 3 4 5 BATT charge current IBATT(A) Note: KIKUSUI : KIKUSUI Electronics Corp. 22 BATT= Electronic load 98 (Product of KIKUSUI PLZ-150W) 96 94 92 90 Vin = 19 V R4 = 82 k 88 86 84 82 80 0 2 4 6 8 10 12 14 BATT charge voltage VBATT(V) 16 18 MB3875/3877 (Continued) Soft-start operating waveforms DC/DC converter switching waveforms Vin = 19 V FOSC = 287.4 kHz Load: BATT = 2 A Vin = 19 V Load: BATT = 50 - INE1 = 0 V 10 V 15 1 s 5V BATT (V) 20 CTL (V) 10 20 OUT (V) 20 0 15 10 10 5 5 0 5V 0 40 0 20 ms 80 120 160 -5 200 t (ms) 0 2 4 6 8 10 t (s) 23 MB3875/3877 NOTES ON USE * Take account of common impedance when designing the earth line on a printed wiring board. * Take measures against static electricity. - For semiconductors, use antistatic or conductive containers. - When storing or carrying a printed circuit board after chip mounting, put it in a conductive bag or container. - The work table, tools and measuring instruments must be grounded. - The worker must put on a grounding device containing 250 k to 1 M resistors in series. * Do not apply a negative voltage - Applying a negative voltage of -0.3 V or less to an LSI may generate a parasitic transistor, resulting in malfunction. ORDERING INFORMATION Part number MB3875PFV MB3877PFV 24 Package 24-pin plastic SSOP (FPT-24P-M03) Remarks MB3875/3877 PACKAGE DIMENSION Note 1) *1 : Resin protrusion. (Each side : +0.15 (.006) MAX) . Note 2) *2 : These dimensions do not include resin protrusion. Note 3) Pins width and pins thickness include plating thickness. Note 4) Pins width do not include tie bar cutting remainder. 24-pin plastic SSOP (FPT-24P-M03) 0.170.03 (.007.001) *17.750.10(.305.004) 24 13 *2 5.600.10 7.600.20 (.220.004) (.299.008) INDEX Details of "A" part +0.20 1.25 -0.10 +.008 .049 -.004 (Mounting height) 0.25(.010) 1 "A" 12 0.65(.026) 0.24 .009 +0.08 -0.07 +.003 -.003 0.13(.005) 0~8 M 0.500.20 (.020.008) 0.600.15 (.024.006) 0.100.10 (.004.004) (Stand off) 0.10(.004) C 2003 FUJITSU LIMITED F24018S-c-4-5 Dimensions in mm (inches) . Note : The values in parentheses are reference values. 25 MB3875/3877 MEMO 26 MB3875/3877 MEMO 27 FUJITSU MICROELECTRONICS LIMITED Shinjuku Dai-Ichi Seimei Bldg. 7-1, Nishishinjuku 2-chome, Shinjuku-ku, Tokyo 163-0722, Japan Tel: +81-3-5322-3347 Fax: +81-3-5322-3387 http://jp.fujitsu.com/fml/en/ For further information please contact: North and South America FUJITSU MICROELECTRONICS AMERICA, INC. 1250 E. Arques Avenue, M/S 333 Sunnyvale, CA 94085-5401, U.S.A. Tel: +1-408-737-5600 Fax: +1-408-737-5999 http://www.fma.fujitsu.com/ Asia Pacific FUJITSU MICROELECTRONICS ASIA PTE LTD. 151 Lorong Chuan, #05-08 New Tech Park, Singapore 556741 Tel: +65-6281-0770 Fax: +65-6281-0220 http://www.fujitsu.com/sg/services/micro/semiconductor/ Europe FUJITSU MICROELECTRONICS EUROPE GmbH Pittlerstrasse 47, 63225 Langen, Germany Tel: +49-6103-690-0 Fax: +49-6103-690-122 http://emea.fujitsu.com/microelectronics/ FUJITSU MICROELECTRONICS SHANGHAI CO., LTD. Rm.3102, Bund Center, No.222 Yan An Road(E), Shanghai 200002, China Tel: +86-21-6335-1560 Fax: +86-21-6335-1605 http://cn.fujitsu.com/fmc/ Korea FUJITSU MICROELECTRONICS KOREA LTD. 206 KOSMO TOWER, 1002 Daechi-Dong, Kangnam-Gu,Seoul 135-280 Korea Tel: +82-2-3484-7100 Fax: +82-2-3484-7111 http://www.fmk.fujitsu.com/ FUJITSU MICROELECTRONICS PACIFIC ASIA LTD. 10/F., World Commerce Centre, 11 Canton Road Tsimshatsui, Kowloon Hong Kong Tel: +852-2377-0226 Fax: +852-2376-3269 http://cn.fujitsu.com/fmc/tw All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with sales representatives before ordering. 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The products described in this document are designed, developed and manufactured as contemplated for general use, including without limitation, ordinary industrial use, general office use, personal use, and household use, but are not designed, developed and manufactured as contemplated (1) for use accompanying fatal risks or dangers that, unless extremely high safety is secured, could have a serious effect to the public, and could lead directly to death, personal injury, severe physical damage or other loss (i.e., nuclear reaction control in nuclear facility, aircraft flight control, air traffic control, mass transport control, medical life support system, missile launch control in weapon system), or (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. Any semiconductor devices have an inherent chance of failure. You must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions. Exportation/release of any products described in this document may require necessary procedures in accordance with the regulations of the Foreign Exchange and Foreign Trade Control Law of Japan and/or US export control laws. The company names and brand names herein are the trademarks or registered trademarks of their respective owners. Edited Strategic Business Development Dept.