FUJITSU SEMICONDUCTOR DATA SHEET ASSP DS04-27704-2E For Power Supply Applications (Lithium ion battery charger) DC/DC Converter IC for Parallel Charging MB3874/MB3876 DESCRIPTION The MB3874 and MB3876 are parallel 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. The IC also enable parallel charging, or charging two batteries at the same time, dramatically reducing the charging time. 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 MB3874 support 3-cell battery and the MB3876 support 4-cell battery. FEATURES * Detecting a voltage drop in the AC adapter and dynamically controlling the charge current (Dynamically-controlled charging) * High efficiency : 93 %(In reverse-current preventive diode) * Wide range of operating supply voltages : 7 V to 25 V * Output voltage precision (Built-in output voltage setting resistor ) : 0.8 % (Ta = + 25 C) * High precision reference voltage source : 4.2 V 0.8 % (Continued) PACKAGE 24-pin plastic SSOP (FPT-24P-M03) MB3874/MB3876 (Continued) * Support for frequency setting using an external resistor (Frequency setting capacitor integrated) :100 kHz to 500 kHz * Built-in current detector amplifier with wide in-phase input voltage range : 0 V to VCC * Built-in standby current function : 0 A (Typ.) * Built-in soft start function * Capable of parallel charging (Charging the two battery packs at a time) * Internal totem-pole output stage supporting P-channel MOS FETs devices 2 MB3874/MB3876 PIN ASSIGNMENT (TOP VIEW) 24 : +INC1 -INC1 : 1 23 : GND FB2 : 2 -INE2 : 3 22 : CS +INE2 : 4 21 : VCC VREF : 5 20 : OUT CTL : 6 19 : VH FB1 : 7 18 : OUTM -INE1 : 8 17 : RT +INE3 : 9 16 : -INE4 -INE3 : 10 15 : FB4 FB3 : 11 14 : -INE5 -INC2 : 12 13 : +INC2 (FPT-24P-M03) 3 MB3874/MB3876 PIN DESCRIPTION 4 Pin No. Symbol I/O Descriptions 1 -INC1 I Output voltage feedback input pin. 2 FB2 O Error amplifier (Error Amp. 2) output pin. 3 -INE2 I Error amplifier (Error Amp. 2) inverted input pin. 4 +INE2 I Error amplifier (Error Amp. 2) non-inverted input pin. Input pin for charge current setting voltage 5 VREF O Reference voltage output pin. 6 CTL I Power supply control pin. Setting the CTL pin low places the IC in the standby mode. 7 FB1 O Error amplifier (Error Amp. 1) output pin. 8 -INE1 I Error amplifier (Error Amp. 1) inverted input pin Input pin for dynamically-controlled charging voltage setting 9 +INE3 I Error amplifier (Error Amp. 3) non-inverted input pin. Input pin for charge current setting voltage 10 -INE3 I Error amplifier (Error Amp. 3) inverted input pin. 11 FB3 O Error amplifier (Error Amp. 3) output pin. 12 -INC2 I Output voltage feedback input pin. 13 +INC2 I Current detection amplifier (Current Amp. 2) input pin . 14 -INE5 I Error amplifier (Error Amp. 5) inverted input pin. 15 FB4 O Error amplifier (Error Amp. 4, 5) output pin. 16 -INE4 I Error amplifier (Error Amp. 4) inverted input pin. 17 RT -- Triangular-wave oscillation frequency setting resistor connection pin. 18 OUTM O Output pin for dynamically controlled charging identification signal "H" level: Constant-voltage or constant-current charging mode "L" level: Dynamically controlled charging mode 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 -- Power supply pin for reference power supply and control circuit. 22 CS -- Soft-start capacitor connection pin. 23 GND -- Ground pin. 24 +INC1 I Current detection amplifier (Current Amp. 1) input pin . MB3874/MB3876 BLOCK DIAGRAM <Error Amp.1> VREF - 208 k + -INE1 8 VCC <MASK Comp.> - + 42 k FB1 -INE2 +INC1 -INC1 +INE2 7 3 24 1 2.5 V <Current Amp.1> <Error Amp.2> VREF + 100 k x 25 - - + <PWM Comp.> + + + + - 4 2 +INC2 -INC2 +INE3 10 13 12 <Current Amp.2> <Error Amp.3> VREF + 100 k - x 25 - + R2 50 k R1 R2 50 k - + + CS 15 22 19 OUT VH (VCC - 5 V) <UVLO> <Error Amp.5> VREF VCC (VCC UVLO) 215 k + - + + 35 k - 0.91 V (0.77 V) VREF (4.2 V) FB4 20 <Error Amp.4> VREF R1 14 Drive <VH> 11 -INE5 <OUT> Bias voltage block FB3 16 VCC VCC 9 -INE4 21 VCC FB2 -INE3 OUTM 18 VREF ULVO <SOFT> VREF 1 A bias 2.5 V 1.5 V CTL <OSC> <Ref> <CTL> 6 (45 pF) RT 17 VREF 5 GND 23 : MB3874 100 k MB3876 150 k 5 MB3874/MB3876 ABSOLUTE MAXIMUM RATINGS Parameter Symbol Conditions Power supply voltage VCC Output terminal current Peak output current OUTM terminal output voltage Power dissipation Storage temperature Rating Unit Min. Max. -- -- 28 V IOUT -- -- 60 mA IOUT Duty 5% (t =1 / fOSC x Duty) -- 500 mA VOUTM -- -- 17 V -- 740* mW -- -55 +125 C PD Ta +25C 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 Power supply voltage VCC Reference voltage output current VH pin output current Input voltage Value Unit Min. Typ. Max. -- 7 -- 25 V IREF -- -1 -- 0 mA IVH -- 0 -- 30 mA V-INC -INC1, -INC2 0 -- 17 V VINE -INE1 to -INE5, +INE2 0 -- VCC - 1.8 V V+INC +INC1, +INC2 0 -- VCC V 0 -- 25 V -- CTL pin input voltage VCTL Output current IOUT OUT pin -45 -- 45 mA Peak output current IOUT Duty 5% (t =1 / fOSC x Duty) -450 -- 450 mA OUTM pin output voltage VOUTM -- -- 3 15 V OUTM pin output current IOUTM -- -- -- 1 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 Ta -- -30 +25 +85 C Operating ambient temperature 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 FUJITSU representatives beforehand. 6 MB3874/MB3876 ELECTRICAL CHARACTERISTICS Reference voltage block (Ref) Parameter Symbol Pin No. Ta = +25C 4.167 4.200 4.233 V Ta = -30C to +85C 4.158 4.200 4.242 V VCC = 7 V to 25 V -- 3 10 mV 5 VREF = 0 mA to -1 mA -- 1 10 mV 5 VREF = 1 V -25 -15 -5 mA VCC = 6.3 6.6 6.9 V VCC = 5.3 5.6 5.9 V 0.7 1.0 1.3 V VREF = 2.6 2.8 3.0 V VREF= 2.4 2.6 2.8 V Output voltage VREF 5 Input stability Line 5 Load stability Load Short-circuit output current IOS VTLH Under voltage lockout protection circuit block (UVLO) Threshold voltage 21 VTHL Hysteresis width VH 21 VTLH Threshold voltage Soft-start block (SOFT) -- 5 VTHL Triangular waveform oscillator circuit block (OSC) (MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. 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 f/fdt 20 Ta = -30C to +85C -- 1* -- % Frequency temperature stability *: Standard design value. (Continued) 7 MB3874/MB3876 (Continued) Error amplifier block (Error Amp.1) Parameter Symbol Pin No FB1 = 2 V, -INE1 = 2.35 V 14.00 14.20 14.40 V MB3874 FB1 = 2 V, -INE1 = 2.83 V 16.80 17.10 17.40 V MB3876 -100 -30 -- nA Threshold voltage VTH Input pin current IIN 8 -INE1= 0 V Voltage gain AV 7 DC -- 100* -- dB Frequency bandwidth BW 7 AV = 0 dB -- 2.0* -- MHz VFBH 7 -- 3.9 4.1 -- V VFBL 7 -- -- 20 200 mV ISOURCE 7 FB1 = 2 V -- -2.0 -0.6 mA Output sink current ISINK 7 FB1 = 2 V 150 300 -- A Input offset voltage VIO 3,4 9,10 FB2 = FB3 = 2 V -- 1* -- mV Input pin current IINE 4,9 +INE2 = +INE3 = 0 V -100 -30 -- nA Common mode input voltage range VCM 3,4 9,10 0 -- VCC-1.8 V Voltage gain AV 2, 11 DC -- 100* -- dB Frequency bandwidth BW 2, 11 AV = 0 dB -- 2.0* -- MHz VFBH 2, 11 -- 3.9 4.1 -- V VFBL 2, 11 -- -- 20 200 mV ISOURCE 2, 11 FB2 = FB3 = 2 V -- -2.0 -0.6 mA ISINK 2, 11 FB2 = FB3 = 2 V 150 300 -- A Output voltage Output source current Error amplifier block (Error Amp.2, 3) (MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. Output voltage Output source current Output sink current 21 -- *: Standard design value. (Continued) 8 MB3874/MB3876 (Continued) Parameter Threshold voltage Symbol Pin No FB4 = 2 V, Ta = +25 C VTH 1, 12 FB1 = 2 V, Ta = -30 C to +85 C IINEH 1, 12 Input current Error amplifier block (Current Amp.4, 5) (MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. IINEL 1, 12 12.500 12.600 12.700 V MB3874 16.666 16.800 16.934 V MB3876 12.474 12.600 12.726 V MB3874 16.632 16.800 16.968 V MB3876 -INC1 = -INC2 = 12.6 V -- 84 150 A MB3874 -INC1 = -INC2 = 16.8 V -- 84 150 A MB3876 VCC = 0 V, -INC1 = -INC2 = 12.6 V -- 0 1 A MB3874 VCC = 0 V, -INC1 = -INC2 = 16.8 V -- 0 1 A MB3876 70 100 130 k MB3874 105 150 195 k MB3876 35 50 65 k R1 1, 12 -- R2 14, 16 -- Voltage gain AV 15 DC -- 100* -- dB Frequency bandwidth BW 15 AV = 0 dB -- 2.0* -- MHz VFBH 15 -- 3.9 4.1 -- V VFBL 15 -- -- 20 200 mV ISOURCE 15 FB4 = 2 V -- -2.0 -0.6 mA ISINK 15 FB4 = 2 V 150 300 -- A Input resistor Output voltage Output source current Output sink current *: Standard design value. (Continued) 9 MB3874/MB3876 (Continued) Parameter Symbol Pin No. I+INCH 13, 24 Input current I+INCL Current detection amplifier block (Current Amp.1, 2) V-INE1 Current detection voltage Common mode input voltage range Voltage gain Constant power detection block (MASK Comp.) PWM comparator block (PWM Comp.) Output voltage (MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. V-INE2 13, 24 3, 10 3, 10 +INC1= +INC2=12.7 V, -INC1= -INC2=12.6 V -- 10 20 A MB3874 +INC1= +INC2=16.9 V, -INC1= -INC2=16.8 V -- 10 20 A MB3876 +INC1= +INC2= 0.1 V, -INC1= -INC2= 0 V -130 -65 -- A +INC1= +INC2=12.7 V, -INC1= -INC2=12.6 V 2.25 2.50 2.75 V MB3874 +INC1= +INC2=16.9 V, -INC1= -INC2=16.8 V 2.25 2.50 2.75 V MB3876 +INC1= +INC2=12.63V, -INC1= -INC2=12.6 V 0.50 0.75 1.00 V MB3874 +INC1= +INC2=16.83 V, -INC1= -INC2=16.8 V 0.50 0.75 1.00 V MB3876 V-INE3 3, 10 +INC1= +INC2= 0.1 V , -INC1= -INC2= 0 V 1.25 2.50 3.75 V V-INE4 3, 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 MB3874 +INC1= +INC2=16.9 V, -INC1= -INC2=16.8 V 22.5 25 27.5 V/V MB3876 AV 3, 10 VOUTCH 3, 10 -- 3.9 4.1 -- V VOUTCL 3, 10 -- -- 20 200 mV VTL 2, 7, Duty cycle = 0 % 11, 15 1.4 1.5 -- V VTH 2, 7, Duty cycle = 100 % 11, 15 -- 2.5 2.6 V Threshold voltage VTLH 18 FB1 = 2.7 2.8 2.9 V VTHL 18 FB1 = 2.4 2.5 2.6 V VH 18 0.2 0.3 0.4 V Output leak current ILEAK 18 OUTM = 5 V -- 0 1 A Output voltage VOL 18 OUTM = 1 mA -- 0.15 0.4 V Threshold voltage Hysteresis width -- (Continued) 10 MB3874/MB3876 (Continued) (MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Parameter Output source current Symbol Pin No. ISOURCE 20 Conditions Typ. Max. OUT = 11 V, Duty 5 % -- -200* -- mA MB3874 OUT = 14 V, Duty 5 % -- -200* -- mA MB3876 OUT = 16 V, Duty 5 % -- 200* -- mA MB3874 OUT = 19 V, Duty 5 % -- 200* -- mA MB3876 (t = 1/fosc x Duty ) Output block (OUT) Control block (CTL) Bias voltage block (VH) 20 (t = 1/fosc x Duty ) (t = 1/fosc x Duty ) ROH 20 OUT = -45 mA -- 8.0 16.0 ROL 20 OUT = 45 mA -- 6.5 13.0 Rise time tr1 20 -- 70* -- ns Fall time tf1 20 -- 60* -- ns VON 6 Active mode 2.0 -- 25.0 V VOFF 6 Standby mode 0 -- 0.8 V ICTLH 6 CTL = 5 V -- 100 200 A ICTLL 6 CTL = 0 V -- 0 1 A Output voltage VH 19 VCC = 7 V to 25 V, VH = 0 to 30 mA VCC - 5.5 VCC - 5.0 VCC - 4.5 V Standby current ICCS 21 CTL = 0 V -- 0 10 A Power supply current ICC 21 CTL = 5 V -- 6.0 9.0 mA MB3874 -- 6.5 9.5 mA MB3876 Output ON resistor General ISINK Unit Remarks Min. (t = 1/fosc x Duty ) Output sink current Value CTL input voltage Input current OUT = 3300 pF (Equivalent to Si4435DY) OUT = 3300 pF (Equivalent to Si4435DY) *: Standard design value 11 MB3874/MB3876 TYPICAL CHARACTERISTICS Reference voltage vs. power supply voltage 10 10 Ta = +25 C CTL = 5 V 8 6 4 2 0 Reference voltage VREF (V) Power supply current ICC (mA) Power supply current vs. power supply voltage Ta = +25 C CTL = 5 V VREF = 0 mA 8 6 4 2 0 0 5 10 15 20 0 25 15 20 25 Reference voltage vs. VREF load current Reference voltage vs. ambient temperature 10 2.0 Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) CTL = 5 V 8 6 4 2 Reference voltage VREF (%) Reference voltage VREF (V) 10 Power supply voltage VCC (V) Power supply voltage VCC (V) 0 5 10 15 20 25 1.0 0.5 0.0 -0.5 -1.0 -1.5 30 Reference voltage vs. CTL pin voltage 0 20 40 60 80 100 CTL pin current vs. CTL pin voltage 6 4 2 1.0 CTL pin current ICTL (A) Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) VREF = 0 mA 8 -20 Ambient temperature Ta (C) VREF load current IREF (mA) 10 VCC = 16 V (MB3874) VCC = 19 V (MB3876) CTL = 5 V VREF = 0 mA 1.5 -2.0 -40 0 Reference voltage VREF (V) 5 Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) 0.8 0.6 0.4 0.2 0.0 0 0 5 10 15 CTL pin voltage VCTL(V) 20 25 0 5 10 15 20 25 CTL pin voltage VCTL (V) (Continued) 12 MB3874/MB3876 Triangular wave oscillator frequency vs. timing resistor 1M Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) 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) Triangular wave oscillator frequency vs. power supply voltage 350 Ta = +25 C CTL = 5 V RT = 47 k 340 330 320 310 300 290 280 270 260 250 0 330 320 310 300 290 280 270 260 250 -40 -20 0 20 40 60 Ambient temperature Ta (C) 15 20 25 80 100 Error amplifier threshold voltage vs. ambient temperature Error amplifier threshold voltage VTH(%) Triangular wave oscillator frequency fOSC(kHz) VCC = 16 V (MB3874) VCC = 19 V (MB3876) CTL = 5 V RT = 47 k 340 10 Power supply voltage VCC (V) Triangular wave oscillator frequency vs. ambient temperature 350 5 5.0 VCC = 16 V (MB3874) VCC = 19 V (MB3876) 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) 13 MB3874/MB3876 (Continued) Error amplifier gain and phase vs. frequency Ta = +25 C AV 4.2 V 20 VCC = 16 V (MB3874) VCC = 19 V (MB3876) 180 90 Phase (deg) Gain AV (dB) 40 0 0 -20 -90 -40 -180 100 1k 10 k 100 k 1M 240 k IN 1 F - + 10 k 2.4 k 10 k 3 - (10) OUT 2 (11) 4 + (9) 2.088 V Error Amp.2 (Error Amp.3) 10 M Frequency f (Hz) Current detection amplifier gain and phase vs. frequency Ta = +25 C 40 VCC = 16 V (MB3874) VCC = 19 V (MB3876) 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) 14 80 100 IN 0.1 V 24 (13) 1 (12) + x 25 - 100 k 3 OUT (10) Current Amp.1 (Current Amp.2) : MB3874 12.6 V MB3876 16.8 V MB3874/MB3876 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 21) 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 as well as a signal to the dynamically controlled charging detection block (MASK Comp.). In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB1 terminal (pin 7) to the -INE1 terminal (pin 8) of the error amplifier, enabling stable phase compensation to the system. (4) Error amplifier block (Error Amp.2, 3) These error amplifiers (Error Amp.2, Error Amp.3) detect the output signals from the current detector amplifiers (Current Amp.1, Current Amp.2), compare them with the +INE2 terminal (pin 4) and +INE3 terminal (pin 9), and output PWM control signals to control the charge current. In addition, these amplifiers allow an arbitrary loop gain to be set by connecting a feedback resistor and capacitor from the FB2 terminal (pin 2) to -INE2 terminal (pin 3) and from the FB3 terminal (pin 11) to -INE3 terminal (pin 10) of the error amplifiers, enabling stable phase compensation to the system. (5) Error amplifier block (Error Amp.4, 5) This error amplifier (Error Amp.4, Error Amp.5) detects the output voltage from the switching rerulator and outputs the PWM control signal. The error amplifier inverted 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 MB3874 and MB3876 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 FB4 terminal (pin 15) to the -INE4 terminal (pin 16) to the -INE5 terminal (pin 14) 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.1, 2) The current detection amplifier (Current Amp.1, Current Amp.2) detects a voltage drop which occurs between both ends of the output sense resistor (RS1) due to the flow of the charge current, using the +INC1 terminal (pin 24) and -INC1 terminal (pin 1). Then it outputs the signal amplified by 25 times to the error amplifier (Error Amp.2) at the next stage.The amplifiers also detect a voltage drop which occurs at both ends of the output sense resistor 15 MB3874/MB3876 (RS2) using the +INC2 terminal (pin 13) and -INC2 terminal (pin 12) and output the signal amplified by 25 times to the error amplifier (Error Amp. 3) at the next stage. (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. 5) 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 6) 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. 4. Additional Functions Dynamically controlled charging detection block (MASK Comp.) The dynamically controlled charging detection block (MASK Comp.) usually output the "H" level signal. The OUTM signal becomes low ("L" level) when the output voltage of the error amplifier (Error Amp. 1) that detects the input voltage (Vcc) becomes lower than the crest value (2.5 V) of the triangular waveform generator (OSC). The OUTM signal return high ("H" level) when the input voltage reaches 2.8 V or more. 16 MB3874/MB3876 METHOD OF SETTING THE CHARGING CURRENT The charge current (output control current) value can be set with the voltage at the +INE2, +INE3 terminal. If a current exceeding the set value attempts to flow, the charge voltage drops according to the set current value. Battery 1 charge current setting voltage : +INE2 +INE2 (V) = 25 x I1 (A) x RS1 () Battery 2 charge current setting voltage : +INE3 +INE3 (V) = 25 x I2 (A) x RS 2 () METHOD OF SETTING THE SOFT START TIME Upon activation, the IC starts charging the capacitor (Cs) connected to the CS terminal . 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) AC ADAPTER VOLTAGE DETECTION When partial potential point A of the AC adapter voltage (Vcc) becomes lower than the voltage at the -INE1 pin, the IC enters the constant-power mode to reduce the charge current in order to keep AC adapter power constant. AC adapter detected voltage setting Vth Vth (V) = (208k + 42k) / 42k x - INE1 =: 5.95 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 - 8 A VCC + 208 k 42 k 17 MB3874/MB3876 OPERATION TIMING DIAGRAM 2.8 V 2.5 V Err Amp.2, 3 FB2,3 Err Amp.4, 5 FB4 Err Amp.1 FB1 1.5 V OUT AC adapter dynamicallycontrolled charging Constant voltage control Constant current control AC adapter dynamicallycontrolled charging OUTM About the OUTM signal The OUTM signal becomes low when the output voltage of the error amplifier (Error Amp. 1) that detects the AC adapter voltage (Vcc) becomes lower than the crest value (2.5 V) of the triangular waveform generator (OSC). If the sum of the current consumption by the system and that by the charger exceeds the current capacity of the AC adapter, the IC detects a voltage drop in the AC adapter output and switches to the dynamically-controlled charging mode from C.V.C.C (constant-voltage/constant-current charging control) mode. In the dynamically-controlled charging mode, the OUTM pin outputs the L level signal to distinguish between the case in which the charge current has become small as the system current consumption has increased and the case in which it has become small as battery charging has been finished. L: Dynamically-controlled charging H: C.V.C.C (constant-voltage/constant-current charging control) or IC standby mode ISYS System Power VIN AC Adaptor Mode Signal Battery Charger MB3874 MB3876 Ichg Battery 18 MB3874/MB3876 NOTE ON AN EXTERNAL REVERSE-CURRENT PREVENTIVE DIODE If there is an imbalance in charge current (I1, I2) under constant-voltage control, voltage is controled at the side with a lower battery voltage and thus the battery voltage at one side is higher than that at the other by the voltage difference between the reverse-current preventive diodes (D1, D2) and between the sense resistors (Rs1, Rs2) Pay attention to the voltage/current characteristics of the reverse-current preventive diode (D1, D2) not to let it exceed the overcharge stop voltage. VCC 21 VIN (16 V/19 V) to 24 pin to 1 pin A OUT 20 B BATT1 RS1 12.6 V/16.8 V I1 D1 19 VH Battery 1 to 13 pin to 12 pin C I2 D BATT2 RS2 12.6 V/16.8 V D2 Battery 2 19 MB3874/MB3876 APPLICATION EXAMPLE R10 2 8 6800 pF C8 R8 47 k R11 30 k R6 330 k <Error Amp.1> VREF - 208 k + -INE1 VCC 7 3900 pF -INE2 C9 +INC1 R16 22 k A 24 B 1 R9 -INC1 150 k R14 5.6 k 0.1 F C13 R19 200 k 3 2.5 V (2.8 V) <Current Amp.1> <Error Amp.2> VREF + 100 k x 25 - - + <PWM Comp.> + + + + - 2 Q2 SW1 R15 5.6 k R18 200 k Q3 3900 pF -INE3 10 33 k C7 +INC2 R12 C 13 R17 22 k D 12 R7 -INC2 150 k 9 0.1 F +INE3 C12 FB3 11 3 14 C6 3900 pF C5 3900 pF R4 200 k R3 200 k FB4 CS CS 2200 pF 15 22 1 50 k C10 0.1 F I1 27 H C3 100 F VH D1 + - D2 C4 100 F + - Pin 13 Pin 12 VCC C 35 k - VREF ULVO CTL <OSC> <Ref> <CTL> RT RT 17 VREF 47 k 5 GND 23 6 1 : MB3874 100 k MB3876 150 k 2 : MB3874 22 k MB3876 15 k 3 : MB3874 16 V MB3876 19 V 4 : MB3874 12.6 V MB3876 16.8 V 4 0.075 Battery 2 bias 2.5 V 1.5 V BATT2 RS2 D3 <SOFT> VREF 1 A D I2 0.91 V (0.77 V) VREF (4.2 V) 0.075 Battery 1 (VCC UVLO) 215 k + - + + B BATT1 RS1 4 L1 (45 pF) 20 - A <UVLO> <Error Amp.5> VREF + - Q1 VCC - + + + Pin 24 Pin 1 OUT 20 <Error Amp.4> VREF 50 k -INE5 Drive <VH> 16 VIN SW2 C14 0.1 F <OUT> Bias voltage 19 block (VCC - 5 V) 1 -INE4 33 k R13 <Current Amp.2> <Error Amp.3> VREF + 100 k - x 25 - + C1 C2 22 F 22 F VCC 21 VCC 4 +INE2 FB2 OUTM + 42 k FB1 18 <MASK Comp.> - MB3874/MB3876 PARTS LIST COMPONET ITEM SPECIFICATION VENDOR PARTS NO. Q1 Q2, Q3 FET FET Si4435DY 2N7002 VISHAY SILICONIX VISHAY SILICONIX Si4435DY 2N7002 D1 D2, D3 Diode Diode MBRS130LT3 RB151L-40F MOTOROLA ROHM MBRS130LT3 RB151L-40F L1 Coil 27 H 2.8 A, 80 m SUMIDA CDRH127-27H C1, C2 C3, C4 OS Condensor OS Condensor 22 F 100 F C5, C6 C7 C8 C9 C10 CS C12, C13 C14 Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor 3900 pF 3900 pF 6800 pF 3900 pF 0.1 F 2200 F 0.1 F 0.1 F 25 V (10 %) 16 V (10 %) 25 V (10 %) 10 % 10 % 10 % 10 % 25 V 10 % 16 V 16 V -- -- R1, R2 R3, R4 RT R6 R7 R8 R9 R10 R11, R12 R13 R14, R15 R16, R17 R18, R19 Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor 0.075 200 k 47 k 330 k 150 k 47 k 150 k 22 k 30 k 30 k 5.6 k 22 k 200 k 1.0 % 1.0 % 1.0 % 5% 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 0.5 % 0.5 % 5% -- -- Note: VISHAY SILICONIX : VISHAY Intertechnology, Inc. MOTOROLA : Motorola Japan Ltd. ROHM : RHOM CO., LTD SUMIDA : SUMIDA ELECTRIC CO., Ltd. 21 MB3874/MB3876 REFERENCE DATA * MB3874 Conversion efficiency vs. charge current (Fixed voltage mode) 100 BATT1 charge voltage = 12.6V, fOSC = 286.37kHz, BATT2 = OPEN (%)=(VBATT1 x IBATT1)/(Vin x Iin) x 100 98 96 94 Conversion effciency (%) Conversion efficiency (%) 100 Conversion efficiency vs. charge voltage (Fixed current mode) Vin = 16 V 92 90 88 86 84 82 98 BATT2= OPEN, BATT1: Electronic load, 96 (Product of KIKUSUI PLZ-150W) 94 92 88 86 84 82 80 80 10 m 100 m 1 Vin = 16 V R10 = 22 k 90 10 0 2 100 IBATTI = IBATT2 Vin = 16 V 92 90 88 86 84 82 100 m 1 10 12 DCC MODE 8 6 4 2 0 0.0 0.2 0.4 DCC : Dynamically-Controlled Charging 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 BATT1 charge current IBATT1 (A) Note: KIKUSUI : KIKUSUI Electronics Corp. 22 16 88 86 84 82 80 0 2 4 6 8 10 12 14 16 BATT voltage vs. BATT charge current 18 BATT1 voltage VBATT1 (V) BATT1 voltage VBATT1 (V) Vin = 16V, BATT2= OPEN, BATT1 : Electronic load, (Product of KIKUSUI PLZ-150W) Dead Battery MODE 14 90 BATT voltage vs. BATT charge current 10 12 BATT1 charge voltage VBATT1 (V) 18 14 10 Paralle charging, 98 BATT1: Electronic load, 96 (Product of KIKUSUI PLZ-150W), IBATTI = IBATT2 94 Vin = 16 V R10 = 22 k 92 BATT1 charge current IBATT1 (A) 16 8 100 Conversion effciency (%) Conversion efficiency (%) Paralle charging, BATT1 charge voltage = 12.6V 98 fOSC = 286.37kHz 96 (%)=((VBATT1 x IBATT1)+(VBATT2 x IBATT2))/(Vin x Iin) x 100 80 10 m 6 Conversion efficiency vs. charge voltage (Fixed current mode) Conversion efficiency vs. charge current (Fixed voltage mode) 94 4 BATT1 charge voltage VBATT1 (V) BATT1 charge current IBATT1 (A) 16 Paralle charging, Vin = 16V, BATT1 : Electronic load, 14 (Product of KIKUSUI PLZ-150W), IBATTI=IBATT2 12 10 Dead Battery MODE DCC MODE 8 6 4 2 0 0.0 0.2 0.4 DCC : Dynamically-Controlled Charging 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 BATT1 charge current IBATT1 (A) MB3874/MB3876 (Continued) Soft start operating waveforms DC/DC converter switching waveforms Vin = 16 V Load : BATT1 = 20 - INE1 = 0 V BATT2 = OPEN Vin = 16 V FOSC = 286.7 kHz Load : BATT1 = 1A BATT2 = OPEN 5V 5V BATT1 (V) 20 15 CTL (V) 20 10 5 OUT (V) 20 15 0 15 10 10 5 5 1 s 0 0 5V 0 40 20 ms 80 120 160 -5 200 t (ms) 0 2 4 6 8 10 t (s) 23 MB3874/MB3876 * MB3876 Conversion efficiency vs. charge voltage (Fixed current mode) Conversion efficiency vs.charge current (Fixed voltage mode) 96 Vin = 19 V 94 92 90 88 86 84 82 98 96 1 96 94 92 Vin = 19 V R10 = 15 k 90 88 86 84 82 10 0 2 4 6 8 10 12 14 16 18 BATT1 charge current IBATT1 (A) BATT1 charge voltage VBATT1 (V) Conversion efficiency vs.charge current (Fixed voltage mode) Conversion efficiency vs. charge voltage (Fixed current mode) 100 Parallel charging, BATT1 Charge voltage =16.8 V, fOSC = 282.71 kHz, (%)=((VBATT1 x IBATT1)+(VBATT2 x IBATT2))/(Vin x Iin) x 100, IBATTI = IBATT2 94 Vin = 19 V 92 90 88 86 84 82 100 m 1 Parallel charging, BATT1 : Electronic load, (Prouct of KIKUSUI PLZ-150W), 98 96 IBATTI = IBATT2 94 92 Vin = 19 V R10 = 15 k 90 88 86 84 82 80 80 10 m 10 0 2 4 6 8 10 12 14 16 BATT1 charge current IBATT1 (A) BATT1 charge voltage VBATT1 (V) BATT voltage vs. BATT charge current BATT voltage vs. BATT charge current 20 Vin = 19V, BATT2 = open, BATT1:Electronic load, (Product of KIKUSUI PLZ-150W) 18 16 14 12 10 Dead Battery MODE DCC MODE 8 6 4 2 0 BATT2 = OPEN, BATT1 : Electronic load, (Prouct of KIKUSUI PLZ-150W) 98 80 100 m Conversion efficiency (%) Conversion efficiency (%) 100 BATT1 voltage VBATT1 (V) Conversion efficiency (%) 98 80 10 m DCC : Dynamically-Controlled Charging 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 BATT1 charge current IBATT1 (A) Note: KIKUSUI : KIKUSUI Electronics Corp. 24 100 BATT1 charge voltage =16.8V, fOSC = 282.71kHz, BATT2 = OPEN, (%)=(VBATT1 x IBATT1)/(Vin x Iin) x 100 1.8 2.0 20 BATT1 voltage VBATT1 (V) Conversion efficiency (%) 100 18 Parallel charging, Vin = 19V, BATT1: Electronic load, (Product of KIKUSUI PLZ-150W), IBATTI = IBATT2 18 16 14 12 10 Dead Battery MODE DCC MODE 8 6 4 2 0 DCC : Dynamically-Controlled Charging 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 BATT1 charge current IBATT1 (A) 1.8 2.0 MB3874/MB3876 (Continued) Soft start operating waveforms DC/DC converter switching waveforms Vin = 19 V FOSC = 282.6 kHz Load : BATT1 = 1 A BATT2 = OPEN Vin = 19 V Load : BATT1 = 50 - INE1 = 0 V BATT2 = OPEN 10 V 15 1 s 5V BATT1 (V) 20 CTL (V) 10 20 OUT (V) 20 0 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) 25 MB3874/MB3876 USAGE PRECAUTIONS 1. Never use settings exceeding maximum rated conditions. Exceeding maximum rated conditions may cause permanent damage to the LSI. Also, it is recommended that recommended operating conditions be observed in normal use. Exceeding recommended operating conditions may adversely affect LSI reliability. 2. Use this device within recommended operating conditions. Recommended operating conditions are values within which normal LSI operation is warranted. Standard electrical characteristics are warranted within the range of recommended operating conditions and within the listed conditions for each parameter. 3. Printed circuit board ground lines should be set up with consideration for common impedance. 4. Take appropriate static electricity measures. * * * * Containers for semiconductor materials should have anti-static protection or be made of conductive material. After mounting, printed circuit boards should be stored and shipped in conductive bags or containers. Work platforms, tools, and instruments should be properly grounded. Working personnel should be grounded with resistance of 250 k to 1 M between body and ground. 5. Do not apply negative voltages. The use of negative voltages below -0.3 V may create parasitic transistors on LSI lines, which can cause abnormal operation ORDERING INFORMATION Part number MB3874PFV MB3876PFV 26 Package 24-pin plastic SSOP (FPT-24P-M03) Remarks MB3874/MB3876 PACKAGE DIMENSION 24-pin plastic SSOP (FPT-24P-M03) * : These dimensions do not include resin protrusion. +0.20 * 7.750.10(.305.004) * 7.750.10(.305.004) 1.25 +0.20 -0.10 1.25 -0.10 +.008 -.004 .049 +.008 .049 -.004 (Mounting height) (Mounting height) 0.10(.004) 0.10(.004) INDEX INDEX 0.650.12(.0256.0047) 0.650.12(.0256.0047) 7.15(.281)REF 7.15(.281)REF CC **5.600.10 5.600.10 (.220.004) (.220.004) +0.10 +0.10 0.22 0.22-0.05 -0.05 +.004 +.004 .009 -.002 .009 -.002 7.600.20 7.600.20 (.299.008) (.299.008) "A" "A" 6.60(.260) 6.60(.260) NOM NOM +0.05 +0.05 0.15 -0.02 -0.02 +.002 .006 +.002 -.001 -.001 Details of of "A" "A" part part Details 0.100.10(.004.004) 0.100.10(.004.004) (STANDOFF) OFF) (STAND 10 00 10 0.500.20 0.500.20 (.020.008) (.020.008) 1994FUJITSU FUJITSULIMITED LIMITEDF24018S-2C-2 F24018S-2C-2 1994 Dimensions in: mm (inches) 27 MB3874/MB3876 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. Semiconductor Division 3545 North First Street San Jose, CA 95134-1804, USA Tel: (408) 922-9000 Fax: (408) 922-9179 Customer Response Center Mon. - Fri.: 7 am - 5 pm (PST) Tel: (800) 866-8608 Fax: (408) 922-9179 http://www.fujitsumicro.com/ Europe FUJITSU MICROELECTRONICS EUROPE GmbH Am Siebenstein 6-10 D-63303 Dreieich-Buchschlag Germany Tel: (06103) 690-0 Fax: (06103) 690-122 http://www.fujitsu-fme.com/ Asia Pacific FUJITSU MICROELECTRONICS ASIA PTE LTD #05-08, 151 Lorong Chuan New Tech Park Singapore 556741 Tel: (65) 281-0770 Fax: (65) 281-0220 http://www.fmap.com.sg/ F0001 FUJITSU LIMITED Printed in Japan All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering. The information and circuit diagrams in this document are presented as examples of semiconductor device applications, and are not intended to be incorporated in devices for actual use. Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams. FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment, industrial, communications, and measurement equipment, personal or household devices, etc.). CAUTION: Customers considering the use of our products in special applications where failure or abnormal operation may directly affect human lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with FUJITSU sales representatives before such use. The company will not be responsible for damages arising from such use without prior approval. 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. If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Law of Japan, the prior authorization by Japanese government will be required for export of those products from Japan.