FUJITSU SEMICONDUCTOR DATA SHEET DS04-27706-1E ASSP For Power Supply Applications (Secondary battery) DC/DC Converter IC for Charging MB3878 ■ DESCRIPTION The MB3878 is a DC/DC converter IC suitable for down-conversion, using pulse-width (PWM) charging and enabling output voltage to be set to any desired level from one cell to four cells. These ICs can dynamically control the secondary battery’s charge current by detecting a voltage drop in an AC adaptor in order to keep its power constant (dynamically-controlled charging). The charging method enables quick charging, for example, with the AC adaptor during operation of a notebook PC. The MB3878 provides a broad power supply voltage range and low standby current as well as high efficiency, making it ideal for use as a built-in charging device in products such as notebook PC. ■ FEATURES • Detecting a voltage drop in the AC adaptor and dynamically controlling the charge current (Dynamically-controlled charging) • Output voltage setting using external resistor : 1 cell to 4 cells • High efficiency : 94 % • Wide range of operating supply voltages : 7 V to 25 V • Output voltage setting accuracy : 4.2V ± 0.8% (per cell) • Built-in frequency setting capacitor enables frequency setting using external resistor only • Oscillator frequency range : 100kHz to 500kHz • Built-in current detector amplifier with wide in-phase input voltage range : 0 V to Vcc • In standby mode, leave output voltage setting resistor open to prevent inefficient current loss • Built-in standby current function : 0 µA (standard) • Built-in soft start function • Built-in totem-pole output stage supporting P-channel MOS FETs devices ■ PACKAGE 24-pin plastic SSOP (FPT-24P-M03) MB3878 ■ PIN ASSIGNMENT (TOP VIEW) 24 : +INC2 −INC2 : 1 23 : GND OUTC2 : 2 +INE2 : 3 22 : CS −INE2 : 4 21 : VCC (O) 20 : OUT FB2 : 5 19 : VH VREF : 6 18 : VCC FB1 : 7 −INE1 : 8 17 : RT +INE1 : 9 16 : −INE3 OUTC1 : 10 15 : FB3 OUTD : 11 14 : CTL −INC1 : 12 13 : +INC1 (FPT-24P-M03) 2 MB3878 ■ PIN DESCRIPTION Pin No. Symbol I/O Descriptions 1 −INC2 I Current detection amplifier (Current Amp. 2) input pin. 2 OUTC2 O Current detection amplifier (Current Amp. 2) output pin. 3 +INE2 I Error amplifier (Error Amp. 2) non-inverted input pin. 4 −INE2 I Error amplifier (Error Amp. 2) inverted input pin. 5 FB2 O Error amplifier (Error Amp. 2) output pin. 6 VREF O Reference voltage output pin. 7 FB1 O Error amplifier (Error Amp. 1) output pin. 8 −INE1 I Error amplifier (Error Amp. 1) inverted input pin 9 +INE1 I Error amplifier (Error Amp. 3) non-inverted input pin. 10 OUTC1 O Current detection amplifier (Current Amp. 1) output pin. 11 OUTD O With IC in standby mode, this pin is left open to prevent loss of current through output voltage setting resistance. Set CTL pin to “H” level and OUTD pin to “L” level. 12 −INC1 I Current detector amplifier (Current Amp. 1) input pin. 13 +INC1 I Current detector 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 pin. 22 CS Soft-start capacitor connection pin. 23 GND Ground pin. 24 +INC2 I Current detection amplifier (Current Amp. 2) input pin. 3 MB3878 ■ BLOCK DIAGRAM −INE1 8 OUTC1 10 <Current Amp.1> + × 25 − −INC1 12 +INC1 13 <Error Amp.1> VREF − + 21 VCC (O) +INE1 9 <PWM Comp.> <OUT> + + + Drive − FB1 7 −INE2 4 OUTC2 2 +INC2 24 −INC2 1 <Current Amp.2> + × 25 − +INE2 3 <Error Amp.2> VREF − 20 OUT VCC 19 VH (VCC − 5 V) Bias Voltage <VH> + FB2 5 2.5 V 1.5 V <UVLO> <Error Amp.3> VREF (VCC UVLO) 215 kΩ + − + + −INE3 16 OUTD 11 − 4.2 V FB3 15 VCC 35 kΩ 0.91 V (0.77 V) VREF UVLO <SOFT> VREF 1 µA VCC bias CS 22 <OSC> (45 pF) 17 RT 4 <REF> 18 VCC <CTL> VREF 5.0 V 6 23 GND VREF 14 CTL MB3878 ■ ABSOLUTE MAXIMUM RAGINGS Parameter Symbol Conditions Rating Unit Min. Max. 28 V 60 mA Power supply voltage VCC Output current IOUT Peak output current IOUT Duty ≤ 5 % (t = 1 / fOSC × Duty) 500 mA Power dissipation PD Ta ≤ +25 °C 740* mW −55 +125 °C Storage temperature VCC, VCC (O) Tstg * : The package is mounted on the dual-sided epoxy board (10 cm × 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 Input voltage VCC, VCC (O) VINE −INE1 to −INE3, +INE1, +INE2 0 VCC − 1.8 V VINC +INC1, +INC2, −INC1, −INC2 0 VCC V OUTD pin output voltage VOUTD 0 17 V OUTD pin output current IOUTD 0 2 mA CTL pin input voltage VCTL 0 25 V output current IOUT −45 45 mA Peak output current IOUT Duty ≤ 5 % (t = 1 / fosc × Duty) −450 450 mA Oscillator frequency fOSC 100 290 500 kHz Timing resistor RT 33 47 130 kΩ Soft-start capacitor CS 2200 100000 pF VH pin capacitor CVH 0.1 1.0 µF Reference voltage output capacitor CREF 0.1 1.0 µF 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. 5 MB3878 ■ ELECTRICAL CHARACTERISTICS Parameter Reference voltage block (Ref) (Ta = +25 °C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Value Pin Symbol Conditions Unit No. Min. Typ. Max. Ta = +25 °C 4.995 5.000 5.045 V Ta = −30 °C to +85 °C 4.945 5.000 5.055 V VCC = 7 V to 25 V 3 10 mV 6 VREF = 0 mA to −1 mA 1 10 mV Ios 6 VREF = 1 V −25 −15 −5 mA VTLH 18 VCC = VCC (O) , VCC = 6.1 6.4 6.7 V VTHL 18 VCC = VCC (O) , VCC = 5.1 5.4 5.7 V VH 18 VCC = VCC (O) 0.7 1.0 1.3 V VTLH 6 VREF = 2.6 2.8 3.0 V VTHL 6 VREF = 2.4 2.6 2.8 V Hysteresis width VH 6 VH = VTLH − VTHL 0.05 0.20 0.35 V Charge current ICS 22 −1.3 −0.8 −0.5 µA Oscillation frequency fOSC 20 RT = 47 kΩ 260 290 320 kHz Frequency temperature stability ∆f/fdt 20 Ta = −30 °C to +85 °C 1* % Input offset voltage VIO 1 5 mV Output voltage VREF 6 Input stability Line 6 Load stability Load Short-circuit output current Threshold voltage Under voltage lockout protection Hysteresis width circuit block (UVLO) Threshold voltage Soft-start block (SOFT) Triangular waveform oscillator circuit block (OSC) 3, 4, FB1 = FB2 = 2 V 8, 9 IB 3, 4, 8, 9 −100 −30 nA Common mode input voltage range VCM 3, 4, 8, 9 0 VCC − 1.8 V Voltage gain AV 5, 7 DC 100* dB Frequency bandwidth BW 5, 7 AV = 0 dB 2.0* MHz VFBH 5, 7 4.7 4.9 V VFBL 5, 7 20 200 mV Input bias current Error amplifier block (Error Amp.1, Error Amp.2) Output voltage Output source current Output sink current ISOURCE 5, 7 FB1 = FB2 = 2 V −2.0 −0.6 mA ISINK 5, 7 FB1 = FB2 = 2 V 150 300 µA * : Standard design value. (Continued) 6 MB3878 Parameter 16 VTH2 16 Input current IINE3 16 FB3 = 2 V, Ta = −30 °C to +85 °C −INE3 = 0 V Voltage gain AV 15 Frequency bandwidth BW 15 VFBH 15 VFBL 15 ISOURCE 15 ISINK Output voltage Output source current Output sink current OUTD pin output leak current OUTD pin output ON resistor 4.167 4.200 4.233 V 4.158 4.200 4.242 V −100 −30 nA DC 100* dB AV = 0 dB 2.0* MHz 4.7 4.9 V 20 200 mV FB3 = 2 V −2.0 −0.6 mA 15 FB3 = 2 V 150 300 µA ILEAK 11 OUTD = 16.8 V 0 1 µA RON 11 OUTD = 1 mA 70 100 Ω I+INCH 13, 24 1, 12 13, 24 1, 12 2, 10 2, 10 2, 10 2, 10 1, 12, 13, 24 +INC1 = +INC2 = 12.7 V, −INC1 = −INC2 = 12.6 V 10 20 µA +INC1 = +INC2 = 12.7 V, −INC1 = −INC2 = 12.6 V 0.1 0.2 µA +INC1 = +INC2 = 0.1 V, −INC1 = −INC2 = 0 V −130 −65 µA +INC1 = +INC2 = 0.1 V, −INC1 = −INC2 = 0 V −140 −70 µA +INC1 = +INC2 = 12.7 V, −INC1 = −INC2 = 12.6 V 2.25 2.5 2.75 V +INC1 = +INC2 = 12.63 V, −INC1 = −INC2 = 12.6 V 0.50 0.75 1.00 V +INC1 = +INC2 = 0.1 V, −INC1 = −INC2 = 0 V 1.25 2.50 3.75 V +INC1 = +INC2 = 0.03 V, −INC1 = −INC2 = 0 V 0.125 0.750 1.375 V 0 Vcc V 22.5 25 27.5 V/V 2.0* MHz I−INCH Input current I+INCL I−INCL VOUTC1 Current detection amplifier block (Current Amp.1, Current Amp.2) FB3 = 2 V, Ta = +25 °C VTH1 Threshold voltage Error amplifier block (Error Amp.3) (Ta = +25 °C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Value Pin Symbol Conditions Unit No. Min. Typ. Max. Current detection voltage VOUTC2 VOUTC3 VOUTC4 Common mode input voltage range VCM Voltage gain AV 2, 10 +INC1 = +INC2 = 12.7 V, −INC1 = −INC2 = 12.6 V Frequency bandwidth BW 2, 10 AV = 0 dB * : Standard design value. (Continued) 7 MB3878 (Continued) Parameter Output voltage Current detection amplifier block Output source (Current Amp.1, current Current Amp.2) Output sink current PWM comparator block Threshold voltage (PWM Comp.) 4.9 V VOUTCL 2, 10 20 200 mV ISOURCE 2, 10 OUTC1 = OUTC2 = 2 V −2.0 −0.6 mA ISINK 2, 10 OUTC1 = OUTC2 = 2 V 150 300 µA VTL 5, 7, Duty cycle = 0 % 15 1.4 1.5 V VTH 5, 7, Duty cycle = 100 % 15 2.5 2.6 V −200* mA ISINK 20 OUT = 16 V, Duty ≤ 5 % (t = 1 / fOSC × Duty) 200* mA Output ON resistor ROH 20 OUT = −45 mA 8.0 12.0 Ω ROL 20 OUT = 45 mA 6.5 9.7 Ω Rise time tr1 20 (equivalent to Si4435 × 1) 70* ns Fall time tf1 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 µA ICTLL 14 CTL = 0 V 0 1 µA Output voltage VH 19 VCC = VCC (O) = 7 V to 25 V, VH = 0 to 30 mA VCC − 5.5 VCC − 5.0 VCC − 4.5 V Standby current ICCS 18, 19 VCC = VCC (O) , CTL = 0 V 0 10 µA Power supply current ICC 18, 19 VCC = VCC (O) , CTL = 5 V 8.0 12.0 mA Control block (CTL) Input current * : Standard design value 8 4.7 OUT = 11 V, Duty ≤ 5 % (t = 1 / fOSC × Duty) CTL input voltage General 20 Output sink current Bias voltage block (VH) 2, 10 VOUTCH ISOURCE Output source current Output block (OUT) (Ta = +25 °C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Value Pin Symbol Conditions Unit No. Min. Typ. Max. OUT = 3300 pF OUT = 3300 pF (equivalent to Si4435 × 1) MB3878 ■ TYPICAL CHARACTERISTICS Power supply current vs. power supply voltage Reference voltage vs. power supply voltage 10 Ta = +25 °C CTL = 5 V 10 Reference voltage VREF (V) Power supply current ICC (mA) 12 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 5 Power supply voltage VCC (V) Reference voltage vs. VREF load current 2.0 Ta = +25 °C VCC = 19 V CTL = 5 V 8 6 4 2 5 10 15 20 25 0.5 0.0 −0.5 −1.0 −1.5 30 0 20 40 60 80 100 Ta = +25 °C VCC = 19 V VREF = 0 mA 6 4 2 CTL pin current vs. CTL pin voltage 1.0 CTL pin current ICTL (mA) Reference voltage VREF (V) −20 Ambient temperature Ta ( °C) Reference voltage vs. CTL pin voltage 8 25 1.0 VREF load current IREF (mA) 10 20 VCC = 19 V CTL = 5 V VREF = 0 mA 1.5 −2.0 −40 0 0 15 Reference voltage vs. ambient temperature Reference voltage ∆VREF (%) Reference voltage VREF (V) 10 10 Power supply voltage VCC (V) Ta = +25 °C VCC = 19 V 0.8 0.6 0.4 0.2 0.0 0 0 0.5 1 1.5 2 CTL pin voltage VCTL (V) 2.5 0 5 10 15 20 25 CTL pin voltage VCTL (V) (Continued) 9 Triangular wave oscillator frequency vs. timing resistor 1M Ta = +25 °C VCC = 19 V CTL = 5 V 100 k 10 k 10 k 100 k 1M Triangular wave oscillator frequency fOSC (kHz) Triangular wave oscillator frequency fOSC (Hz) MB3878 Triangular wave oscillator frequency vs. power supply voltage 340 Ta = +25 °C CTL = 5 V RT = 47 kΩ 330 320 310 300 290 280 270 260 250 240 0 Timing resistor RT (Ω) Triangular wave oscillator frequency fOSC (kHz) 320 310 300 290 280 270 260 250 240 −40 −20 0 20 40 60 80 Ambient temperature Ta ( °C) 100 Error amplifier threshold voltage ∆VTH (%) VCC = 19 V CTL = 5 V RT = 47 kΩ 330 10 15 20 25 Power supply voltage VCC (V) Error amplifier threshold voltage vs. ambient temperature (Error Amp.3) Triangular wave oscillator frequency 340 5 5.0 VCC = 19 V 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) (Continued) 10 MB3878 (Continued) Error amplifier gain and phase vs. frequency 40 Ta = +25 °C AV 180 VCC = 19 V φ 20 90 0 0 240 kΩ Phase φ (deg) Gain AV (dB) 5.2 V −20 −90 −40 −180 1k 10 k 100 k 1M IN 1 µF − + 10 kΩ 2.4 kΩ 10 kΩ 8 (4) − OUT 7 (5) 9 + (3) 2.5 V Error Amp.1 (Error Amp.2) 10 M Frequency f (Hz) Current detection amplifier gain and phase vs. frequency 180 90 AV 0 0 −20 −90 VCC = 19 V Phase φ (deg) 20 Gain AV (dB) Ta = +25 °C φ 40 12.6 V −40 13 + OUT (24) ×25 10 (2) 12 − (1) 12.55 V Current Amp.1 (Current Amp.2) −180 1k 10 k 100 k 1M 10 M 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 80 Ambient temperature Ta ( °C) 100 11 MB3878 ■ 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 (5.0V typ.) used as the reference supply voltage for the IC’s internal circuitry. This pin can also be used to obtain a load current to a maximum of 1mA from the reference voltage VREF terminal (pin 6). (2) Triangular wave oscillator block (OSC) The triangular wave oscillator builds the capacitor for frequency setting into, and generates the triangular wave oscillator waveform by connecting the frequency setting resistor with 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 amplifier detects the output signal from the current detector ampifier (Current amp .1), compares this to the +INE1 terminal (pin 9), and outputs a PWM control signal to be used in controlling the charging current. In addition, an arbitrary loop gain can be set up by connecting a feedback resistor and capacitor between the FB1 terminal (pin 7) and -INE terminal (pin 8), providing stable phase compensation to the system. (4) Error amplifier block (Error Amp.2) This amplifier (Error Amp.2) detects voltage pendency of the AC adaptor and outputs a PWM control signal. In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB2 terminal (pin 5) to the -INE2 terminal (pin 4) 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. External output voltage setting resistors can be connected to the error amplifier inverse input pin to set the desired level of output voltage from 1 cell to 4 cells. 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.1) The current detection amplifier (Current Amp.1) 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 +INC1 terminal (pin 13) and −INC1 terminal (pin 12). Then it outputs the signal amplified by 25 times to the error amplifier (Error Amp.1) at the next stage. 12 MB3878 (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 (typ.) 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 µA at maximum in the standby mode.) (10) Bias voltage block (VH) The bias voltage circuit outputs Vcc − 5 V (typ.) as the minimum potential of the output circuit. In the standby mode, this circuit outputs the potential equal to Vcc. 2. Protection Functions Under voltage lockout protection 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 under voltage lockout protection 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 under voltage lockout protection 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. 13 MB3878 ■ SETTING THE CHARGING VOLTAGE The charging voltage (DC/DC output voltage) can be set by connecting external voltage setting resistors (R3, R4) to the -INE3 terminal. Be sure to select a resistor value that allows you to ignore the on resistor (70 Ω, 1mA) of the internal FET connected to the OUTD terminal (pin 11). Battery charging voltage: VO VO (V) = (R3 + R4) / R4 × 4.2 (V) B VO R3 < Error Amp.3 > −INE3 16 R4 11 OUTD − + + 4.2 V 22 CS ■ METHOD OF SETTING THE CHARGING CURRENT The charge current (output control current) value can be set with the voltage at the +INE1 terminal (pin 9). 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 : +INE1 +INE1 (V) = 25 × I1 (A) × RS (Ω) ■ 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 terminal 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 × CS (µF) ■ METHOD OF SETTING THE TRIANGULAR WAVE OSCILLATOR FREQUENCY 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) =: 13630 / RT (kΩ) 14 MB3878 ■ AC ADAPTOR VOLTAGE DETECTION With an external resistor connected to the +INE2 terminal(pin 3), the IC enters the dynamically-controlled charging mode to reduce the charge current to keep AC adaptor power constant when the partial potential point A of the AC adaptor voltage (Vcc) becomes lower than the voltage at the -INE2 terminal. AC adaptor detected voltage setting: Vth Vth (V) = (R1 + R2) / R2 × −INE2 −INE2 setting voltage range : 1.176 V to 4.2 V (equivalent to 7 V to 25 V for Vcc) <Error Amp.2> −INE2 4 − 3 + A VCC R1 +INE2 R2 ■ OPERATION TIMING DIAGRAM 2.5 V Error Amp.1 FB1 Error Amp.3 FB3 Error Amp.2 FB2 1.5 V OUT AC adaptor dynamically- Constant controlled charging voltage control Constant current control AC adaptor dynamicallycontrolled charging 15 MB3878 ■ PROCESSING WITHOUT USE OF THE CS PIN If the soft start function is not used, the CS terminal (pin 22) should be left open. Open CS 22 When no soft start time is specified. ■ NOTE ON AN EXTERNAL REVERSE-CURRENT PREVENTIVE DIODE • Insert a reverse-current preventive diode at one of the three locations marked * to prevent reverse current from the battery. • When selecting the reverse current prevention diode, be sure to consider the reverse voltage (VR) and reverse current (IR) of the diode. 21 VCC(O) VIN ∗ A 20 B OUT ∗ I1 RS ∗ VH 19 16 Battery BATT SW R16 R15 200 kΩ 110 Ω Q2 R14 1.3 kΩ R6 68 kΩ R5 330 kΩ R4 82 kΩ 8 FB2 5 CS 2200 pF 15 CS 22 FB3 R18 200 kΩ −INE3 16 R17 C6 100 kΩ 1500 pF 11 R3 OUTD 330 kΩ R7 22 kΩ +INE2 3 <SOFT> VREF 1 µA C8 4 10000 pF OUTC2 R10 2 <Current Amp.2> 30 kΩ +INC2 24 + R11 × 25 30 kΩ −INC2 1 − −INE2 OUTC1 10 <Current Amp.1> C10 5600 pF +INC1 + A 13 R9 × 25 10 kΩ − B −INC1 12 R12 30 kΩ +INE1 9 R13 FB1 30 kΩ 7 R8 100 kΩ −INE1 4.2 V RT RT 47 kΩ (45 pF) VCC 2.5 V 1.5 V VREF UVLO VREF 6 <CTL> VCC C9 0.1 µF VREF 5.0 V 23 GND <REF> bias 35 kΩ 0.91 V (0.77 V) − VCC (O) 20 14 18 C2 100 µF L1 12 µH + − C1 22 µF A B + Battery − C3 100 µF BATT AC Adaptor RS 0.033 Ω I1 VIN C7 0.1 µF Output voltage (Battery voltage) is adjustable D1 Q1 + − IIN Note : SW ON : DCC MODE SW OFF : Dead Battery MODE Range of input voltage VIN=13V to 21V(at Load = 3A) CTL VCC VH OUT C5 0.1 µF 21 19 (VCC − 5 V) (VCC UVLO) 215 kΩ + <UVLO> Bias Voltage <VH> VCC <PWM Comp.> <OUT> + + + Drive − 17 <OSC> <Error Amp.3> VREF − + + + <Error Amp.2> VREF − + <Error Amp.1> VREF − MB3878 ■ APPLICATION EXAMPLE 1 17 MB3878 ■ PARTS LIST (for APPLICATION EXAMPLE 1) COMPONENT ITEM SPECIFICATION VENDOR PARTS No. Q1 Q2 FET FET Si4435DY 2N7002 VISHAY SILICONIX VISHAY SILICONIX Si4435DY 2N7002 D1 Diode MBRS130LT3 MOTOROLA MBRS130LT3 L1 Coil 12 µH 4.0 A, 38 mΩ SUMIDA CDRH124-12 µH C1 C2, C3 CS C5 C6 C7 C8 C9 C10 OS Condenser OS Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser 22 µF 100 µF 2200 pF 0.1 µF 1500 pF 0.1 µF 10000 pF 0.1 µF 5600 pF 25 V (10 %) 25 V (10 %) 10 % 16 V 10 % 25 V 10 % 16 V 10 % RS RT R3 R4 R5 R6 R7 R8 R9 R10 to R13 R14 R15 R16 R17 R18 Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor 0.033 Ω 47 kΩ 330 kΩ 82 kΩ 330 kΩ 68 kΩ 22 kΩ 100 kΩ 10 kΩ 30 kΩ 1.3 kΩ 110 Ω 200 kΩ 100 kΩ 200 kΩ 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 5% 0.5 % 0.5 % Note 18 VISHAY SILICONIX : VISHAY Intertechnology, Inc. MOTOROLA : Motorola Japan Ltd. SUMIDA : SUMIDA ELECTRIC CO., Ltd. MB3878 ■ REFERENCE DATA Conversion efficiency vs. charge current (Fixed voltage mode) VIN = 19 V BATT charge voltage = 12.6 V fOSC = 277.9 kHz η (%) = (VBATT × IBATT) / (VIN × IIN) × 100 98 96 94 92 90 88 86 84 82 80 10 m 100 m 1 10 100 Conversion efficiency η (%) Conversion efficiency η (%) 100 Conversion efficiency vs. charge voltage (Fixed current mode) VIN = 19 V BATT : Electronic load, (Product of KIKUSUI PLZ-150W) 98 96 94 92 90 88 86 84 82 80 0 2 BATT charge current IBATT (A) 4 6 8 10 12 14 16 BATT charge voltage VBATT (V) BATT voltage vs. BATT charge current BATT voltage VBATT (V) 18 VIN = 19 V BATT : Electronic load, (Product of KIKUSUI PLZ-150W) 16 14 12 10 DCC MODE Dead Battery MODE 8 6 4 2 DCC : Dynamically Controlled Charging 0 0 1 2 3 BATT charge current 4 5 IBATT (A) DC/DC converter switching waveforms Soft start operating waveforms VIN = 19 V Load : BATT = 20 Ω −INE2 = 0 V BATT (V) 20 OUTH (V) 20 5V 15 5V 15 CTL (V) 10 5 20 10 0 0 15 VIN = 19 V fOSC = 277.9 kHz Load : BATT = 1 A 5 10 FB3 (V) 4 5 2 0 5V 0 40 20 ms 80 120 160 200 t (ms) 1 µs 2V 0 0 2 4 6 8 10 t (µs) 19 20 R21 100 kΩ R22 100 kΩ − − R20 100 kΩ VIN + A(2/2) Q2 R19 100 kΩ + A(1/2) VIN SW R16 200 kΩ R15 110 Ω CS 2200 pF C6 1500 pF R3 330 kΩ R18 200 kΩ D R7 22 kΩ R10 24 kΩ R11 36 kΩ C R23 100 kΩ B A C8 10000 pF R13 30 kΩ C10 5600 pF R9 10 kΩ R14 R12 1.3 kΩ 30 kΩ 8 15 CS 22 FB3 −INE3 16 R17 100 kΩ 11 OUTD FB2 5 +INC2 24 <SOFT> VREF 1 µA <Current Amp.2> + × 25 −INC2 1 − +INE2 3 4 7 9 13 OUTC2 2 −INE2 FB1 +INE1 +INC1 <Current Amp.1> + × 25 −INC1 − 12 OUTC1 10 R8 100 kΩ −INE1 4.2 V RT RT 47 kΩ (45 pF) VCC 2.5 V 1.5 V VREF UVLO VREF 6 <CTL> VCC C9 0.1 µF VREF 5.0 V 23 GND <REF> bias 35 kΩ 0.91 V (0.77 V) − VCC (O) 20 CTL VCC C2 100 µF L1 12 µH + − C1 22 µF B + Battery − C3 100 µF RS1 0.033 Ω A RS2 0.033 Ω D BATT System C7 0.1 µF Output voltage (Battery voltage) is adjustable D1 Q1 + − C Note : SW ON : Differential Charging MODE SW OFF : Dead Battery MODE Range of input voltage VIN = 13V to 21V(at Load = 3A) 14 18 VH OUT C5 0.1 µF 21 19 (VCC − 5 V) (VCC UVLO) 215 kΩ + <UVLO> Bias Voltage <VH> VCC <PWM Comp.> <OUT> + + + Drive − 17 <OSC> <Error Amp.3> VREF − + + + <Error Amp.2> VREF − + <Error Amp.1> VREF − VIN AC Adaptor MB3878 ■ APPLICATION EXAMPLE 2 MB3878 ■ PARTS LIST (for APPLICATION EXAMPLE 2) COMPONENT ITEM SPECIFICATION VENDOR PARTS No. Q1 Q2 FET FET Si4435DY 2N7002 VISHAY SILICONIX VISHAY SILICONIX Si4435DY 2N7002 D1 Diode MBRS130LT3 MOTOROLA MBRS130LT3 A Dual Op-amp MB47358 Our Company MB47358 L1 Coil 12 µH 4.0 A, 38 mΩ SUMIDA CDRH124-12 µH C1 C2, C3 CS C5 C6 C7 C8 C9 C10 OS Condenser OS Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser 22 µF 100 µF 2200 pF 0.1 µF 1500 pF 0.1 µF 10000 pF 0.1 µF 5600 pF 25 V (10 %) 25 V (10 %) 10 % 16 V 10 % 25 V 10 % 16 V 10 % RS1, RS2 RT R3 R7 R8 R9 R10 R11 R12, R13 R14 R15 R16 R17 R18 R19, R20 R21, R22 R23 Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor 0.033 Ω 47 kΩ 330 kΩ 22 kΩ 100 kΩ 10 kΩ 36 kΩ 27 kΩ 30 kΩ 1.3 kΩ 110 Ω 200 kΩ 100 kΩ 200 kΩ 100 kΩ 100 kΩ 100 kΩ 1.0 % 1.0 % 1.0 % 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 0.5 % 0.5 % 5% 1.0 % 0.5 % 1.0 % 0.5 % 1.0 % Note VISHAY SILICONIX : VISHAY Intertechnology, Inc. MOTOROLA : Motorola Japan Ltd. SUMIDA : SUMIDA ELECTRIC CO., Ltd. 21 MB3878 ■ USAGE PRECAUTIONS • Printed circuit board ground lines should be set up with consideration for common impedance. • 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 kΩ to 1 MΩ between body and ground. • 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 MB3878PFV 22 Package 24-pin plastic SSOP (FPT-24P-M03) Remarks MB3878 ■ PACKAGE DIMENSION 24-pin plastic SSOP (FPT-24P-M03) * : These dimensions do not include resin protrusion. +0.20 * 7.75±0.10(.305±.004) 1.25 –0.10 +.008 .049 –.004 (Mounting height) 0.10(.004) * 5.60±0.10 INDEX 0.65±0.12(.0256±.0047) (.220±.004) +0.10 C 6.60(.260) NOM "A" +0.05 0.22 –0.05 0.15 –0.02 +.004 –.002 .006 –.001 .009 7.15(.281)REF 7.60±0.20 (.299±.008) Details of "A" part +.002 0.10±0.10(.004±.004) (STAND OFF) 0 10° 0.50±0.20 (.020±.008) 2000 FUJITSU LIMITED F24018S-2C-3 Dimensions in mm (inches). 23 MB3878 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 North First Street, San Jose, CA 95134-1804, U.S.A. Tel: +1-408-922-9000 Fax: +1-408-922-9179 Customer Response Center Mon. - Fri.: 7 am - 5 pm (PST) Tel: +1-800-866-8608 Fax: +1-408-922-9179 http://www.fujitsumicro.com/ Europe FUJITSU MICROELECTRONICS EUROPE GmbH Am Siebenstein 6-10, D-63303 Dreieich-Buchschlag, Germany Tel: +49-6103-690-0 Fax: +49-6103-690-122 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/ Korea FUJITSU MICROELECTRONICS KOREA LTD. 1702 KOSMO TOWER, 1002 Daechi-Dong, Kangnam-Gu,Seoul 135-280 Korea Tel: +82-2-3484-7100 Fax: +82-2-3484-7111 F0008 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. The contents of this document may not be reproduced or copied without the permission of FUJITSU LIMITED. FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipments, industrial, communications, and measurement equipments, 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 inherently a certain rate 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 Control Law of Japan, the prior authorization by Japanese government should be required for export of those products from Japan.