MB3877PFV

FUJITSU SEMICONDUCTOR DATA SHEET DS04-27703-4E ASSP For Power Supply Applications (Lithium ion battery charger) DC/DC Converter IC for Charging MB3875/MB3877 s 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. s 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) s PACKAGE 24-pin plastic SSOP (FPT-24P-M03) 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 µA (Typ) • On-chip soft-start function • Internal totem-pole output stage supporting P-channel MOS FETs devices s PIN ASSIGNMENT (TOP VIEW) −INC2 : 1 IN3 : 2 FB2 : 3 OUTC2 : 4 VREF : 5 −INE2 : 6 +INE2 : 7 +INE1 : 8 FB1 : 9 OUTC1 : 10 −INE1 : 11 −INC1 : 12 24 : +INC2 23 : GND 22 : CS 21 : VCC (O) 20 : OUT 19 : VH 18 : VCC 17 : RT 16 : −INE3 15 : FB3 14 : CTL 13 : +INC1 (FPT-24P-M03) 2 MB3875/3877 s PIN DESCRIPTION Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Symbol –INC2 IN3 FB2 OUTC2 VREF –INE2 +INE2 +INE1 FB1 OUTC1 –INE1 –INC1 +INC1 CTL FB3 –INE3 RT VCC VH OUT VCC(O) CS GND +INC2 I/O I I O O O I I I O O I I I I O I — — O O — — — I Descriptions Current detection amplifier (Current Amp. 2) input pin. DC/DC output voltage (charge voltage) input pin. Error amplifier (Error Amp. 2) output pin. Current detection amplifier (Current Amp. 2) output pin. Reference voltage output pin. Error amplifier (Error Amp. 2) inverted input pin. Error amplifier (Error Amp. 2) non-inverted input pin. Error amplifier (Error Amp. 1) non-inverted input pin Error amplifier (Error Amp. 1) output pin. Current detection amplifier (Current Amp. 1) output pin. Error amplifier (Error Amp. 1) inverted input pin. Current detection amplifier (Current Amp. 1) input pin. Current detection amplifier (Current Amp. 1) input pin. Power supply control pin. Setting the CTL pin low places the IC in the standby mode. Error amplifier (Error Amp. 3) output pin. Error amplifier (Error Amp. 3) inverted input pin. Triangular-wave oscillation frequency setting resistor connection pin. Power supply pin for reference power supply and control circuit. Power supply pin for FET drive circuit (VH = Vcc − 5 V). High-side FET gate drive pin. Output circuit power supply. Soft-start capacitor connection pin. Ground pin. Current detection amplifier (Current Amp. 2) input pin. 3 MB3875/3877 s BLOCK DIAGRAM −INE1 11 OUTC1 + × 25 −INC1 − 12 +INC1 13 +INE1 FB1 −INE2 OUTC2 +INC2 −INC2 +INE2 8 9 6 4 24 1 7 3 10 VREF − + + + + − + × 25 − VREF − + OUT Drive 20 21 VCC (O) VCC Bias voltage block 19 (VCC − 5 V) VH FB2 IN3 2 VCC −INE3 R1 16 ∗ VREF − + + R2 50 kΩ (VCC UVLO) 215 kΩ + − 35 kΩ FB3 15 VREF 1 µA VREF (4.2 V) 0.91 V (0.77 V) VREF ULVO VCC CS 22 VCC 18 CTL 2.5 V 1.5 V (45 pF) RT 17 bias 14 VREF 5 GND 23 ∗ : MB3875 100 kΩ MB3877 150 kΩ 4 MB3875/3877 s ABSOLUTE MAXIMUM RAGINGS Parameter Power supply voltage Output current Peak output current Power dissipation Storage temperature Symbol VCC IOUT IOUT PD Tstg Ta ≤ +25°C — Conditions VCC,VCC(O) — Duty ≤ 5% (t =1 / fOSC × Duty) Rating Min — — — — –55 Max 28 60 500 740* +125 Unit V mA mA mW °C *: 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. s RECOMMENDED OPERATING CONDITIONS Parameter Power supply voltage Reference voltage output current VH pin output current Input voltage CTL pin input voltage Output current Peak output current Oscillator frequency Timing resistor Soft-start capacitor VH pin capacitor Reference voltage output capacitor Symbol VCC IREF IVH VIN VINE VINC VCTL IOUT IOUT fOSC RT CS CVH CREF Ta IN3 Conditions VCC,VCC(O) — — –INE1,–INE2,+INE1,+INE2 +INC1,+INC2,–INC1,–INC2, — — Duty ≤ 5% (t =1 / fOSC × Duty) — — — — — — Value Min 7 –1 0 0 0 0 0 –45 –450 100 33 — — — –30 Typ — — — — — — — — — 290 47 2200 0.1 0.1 +25 Max 25 0 30 17 VCC – 1.8 VCC 25 45 450 500 130 100000 1.0 1.0 +85 Unit V mA mA V V V V mA mA kHz kΩ pF µF µF °C Operating 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 MB3875/3877 s ELECTRICAL CHARACTERISTICS (MB3875: Ta = +25°C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25°C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Reference voltage block (Ref) Output voltage Input stability Load stability Short-circuit output current Threshold voltage VTHL Under voltage lockout protection circuit block (UVLO) Hysteresis width VH VTLH Threshold voltage VTHL Hysteresis width Triangular waveform Soft-start block oscillator circuit (SOFT) block (OSC) VH 5 5 VREF= — 2.4 0.05 2.6 0.20 2.8 0.35 V V 18 Symbol Pin No. Conditions Ta = +25°C Ta = –30°C to +85°C VCC = 7 V to 25 V VREF = 0 mA to –1 mA VREF = 1 V VCC =VCC (O), VCC = Value Min 4.167 4.158 — — –25 6.3 5.3 0.7 2.6 Typ 4.200 4.200 3 1 –15 6.6 5.6 1.0 2.8 Max 4.233 4.242 10 10 –5 6.9 5.9 1.3 3.0 Unit Remarks V V mV mV mA V V V V VREF Line Load IOS VTLH 5 5 5 5 18 VCC =VCC (O), VCC = VCC =VCC (O) VREF = 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* — % *: Standard design value. (Continued) 6 MB3875/3877 (MB3875: Ta = +25°C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25°C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Input offset voltage Input bias current Error amplifier block (Error Amp.1, 2) Common mode input voltage range Voltage gain Frequency bandwidth Output voltage Output source current Output sink current Symbol Pin No VIO IB Conditions Value Min — –100 Typ 1 –30 Max 5 — Unit Remarks mV nA 6,7,8,11 FB1 = FB2 = 2 V 6,7,8,11 — VCM AV BW VFBH VFBL ISOURCE ISINK 6,7,8,11 3,9 3,9 3,9 3,9 3,9 3,9 DC AV = 0 dB — 0 — — — 100* 2.0* 4.1 20 –2.0 300 VCC–1.8 — — — 200 –0.6 — V dB MHz V mV mA µA V V V V µA µA µA µA kΩ kΩ kΩ dB MHz V mV mA µA MB3875 MB3877 MB3875 MB3877 MB3875 MB3877 MB3875 MB3877 MB3875 MB3877 — — FB1 = FB2 = 2 V FB1 = FB2 = 2 V FB3 = 2 V, Ta = +25 °C 3.9 — — 150 12.500 12.600 12.700 16.666 16.800 16.934 12.474 12.600 12.726 16.632 16.800 16.968 — — — — 70 105 35 — — 84 84 0 0 100 150 50 100* 2.0* 4.1 20 –2.0 300 150 150 1 1 130 195 65 — — — 200 –0.6 — Threshold voltage VTH 2 FB3 = 2 V, Ta = –30 °C to +85 °C IINE3H Input current Error amplifier block (Error Amp.3) IINE3L R1 R2 Voltage gain Frequency bandwidth Output voltage Output source current Output sink current *: Standard design value. AV BW VFBH VFBL ISOURCE ISINK 2 2 2 16 15 15 15 15 15 15 IN3 = 12.6 V IN3 = 16.8 V VCC = 0 V, IN3 = 12.6 V VCC = 0 V, IN3 = 16.8 V — — DC AV = 0 dB — — FB3 = 2 V FB3 = 2 V Input resistor 3.9 — — 150 (Continued) 7 MB3875/3877 (MB3875: Ta = +25°C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877: Ta = +25°C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Symbol Pin No. Conditions +INC1= +INC2=12.7 V –INC1= –INC2=12.6 V +INC1= +INC2=16.9 V –INC1= –INC2=16.8 V +INC1= +INC2=12.7 V –INC1= –INC2=12.6 V +INC1= +INC2=16.9 V –INC1= –INC2=16.8 V +INC1= +INC2= 0.1 V –INC1= –INC2= 0 V +INC1= +INC2= 0.1V –INC1= –INC2= 0 V +INC1= +INC2=12.7 V –INC1= –INC2=12.6 V +INC1= +INC2=16.9 V –INC1= –INC2=16.8 V +INC1= +INC2=12.63V –INC1= –INC2=12.6 V +INC1= +INC2=16.83V –INC1= –INC2=16.8 V +INC1= +INC2= 0.1 V –INC1= –INC2= 0 V +INC1= +INC2= 0.03 V –INC1= –INC2= 0 V — +INC1= +INC2=12.7 V –INC1= –INC2=12.6 V +INC1= +INC2=16.9 V –INC1= –INC2=16.8 V AV = 0 d B — — OUTC1 = OUTC2 = 2 V OUTC1 = OUTC2 = 2 V Value Min — — — — –130 –140 2.25 2.25 0.50 0.50 1.25 0.125 0 22.5 22.5 — 3.9 — — 150 Typ 10 10 0.1 0.1 –65 –70 2.5 2.5 0.75 0.75 2.50 0.750 — 25 25 2.0* 4.1 20 –2.0 300 200 –0.6 — Max 20 20 0.2 0.2 — — 2.75 2.75 1.00 1.00 3.75 1.375 VCC 27.5 27.5 — Unit Remarks µA MB3875 µA MB3877 µA MB3875 µA MB3877 µA µA V V V V V V V V/V MB3875 V/V MB3877 MHz V mV mA µA MB3875 MB3877 MB3875 MB3877 I+INCH 13, 24 Input current I–INCH 1, 12 I+INCL I–INCL 13, 24 1, 12 VOUTC1 Current detection amplifier block (Current Amp.1,2) 4, 10 Current detection voltage VOUTC2 4, 10 VOUTC3 VOUTC4 Common mode input voltage range VCM 4, 10 4, 10 1, 12, 13, 24 Voltage gain AV 4, 10 Frequency bandwidth Output voltage Output source current Output sink current *: Standard design value. BW VOUTCH VOUTCL ISOURCE ISINK 4, 10 4, 10 4, 10 4, 10 4, 10 (Continued) 8 MB3875/3877 (Continued) (MB3875 : Ta = +25°C, VCC = 16 V, VCC (O) = 16 V, VREF = 0mA) (MB3877 : Ta = +25°C, VCC = 19 V, VCC (O) = 19 V, VREF = 0mA) Parameter PWM comparator block (PWM Comp.) Symbol Pin No. Conditions Value Min 1.4 Typ 1.5 Max — Unit Remarks VTL Threshold voltage VTH 3,9,15 Duty cycle = 0 % V 3,9,15 Duty cycle = 100 % OUT = 11 V Duty ≤ 5 % — 2.5 2.6 V Output source current ISOURCE 20 (t = 1/fosc × Duty ) OUT = 14 V Duty ≤ 5 % OUT = 16 V Duty ≤ 5 % — –200* — mA MB3875 (t = 1/fosc × Duty ) Output block (OUT) — –200* — mA MB3877 Output sink current ISINK 20 (t = 1/fosc × Duty ) OUT = 19 V Duty ≤ 5 % — 200* — mA MB3875 (t = 1/fosc × Duty ) Output ON resistor Rise time Fall time ROH ROL tr1 tf2 VON VOFF ICTLH ICTLL VH 20 20 20 20 14 14 14 14 19 OUT = −45 mA OUT = 45 mA OUT = 3300 pF (Equivalent to Si4435DY) — — — — — 2 0 — — 200* 8.0 6.5 70* 60* — — 100 0 — 16 13 — — 25 0.8 200 1 mA MB3877 Ω Ω ns ns V V µA µA V OUT = 3300 pF (Equivalent to Si4435DY) Bias Control block voltage (CTL) block (VH) CTL input voltage Input current Active mode Standby mode CTL = 5 V CTL = 0 V VCC = VCC(O) = 7 V to 25 V, VH = 0 to 30 mA VCC = VCC(O), CTL = 0 V VCC = VCC(O), CTL = 5 V Output voltage VCC–5.5 VCC–5.0 VCC–4.5 General Standby current Power supply current ICCS ICC 18 18 — — — 0 6.0 6.5 10 9.0 9.5 µA mA MB3875 mA MB3877 *: Standard design value. 9 MB3875/3877 s TYPICAL CHARACTERISTICS Power supply current vs. power supply voltage Power supply current ICC (mA) 10 8 6 Reference voltage vs. power supply voltage 10 Reference voltage VREF (V) Ta = +25 °C CTL = 5 V 8 6 4 2 0 0 5 10 15 Ta = +25 °C CTL = 5 V VREF = 0 mA 4 2 0 0 5 10 15 20 25 20 25 Power supply voltage VCC (V) Reference voltage vs. VREF load current 10 Power supply voltage VCC (V) Reference voltage vs. ambient temperature Reference voltage ∆VREF (%) 2.0 1.5 1.0 0.5 0.0 −0.5 −1.0 −1.5 −2.0 −40 −20 0 20 40 60 80 100 VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V VREF = 0 mA Reference voltage VREF (V) 8 6 4 2 0 0 5 10 15 Ta = +25 °C VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V 20 25 30 VREF load current IREF (mA) Reference voltage vs. CTL pin voltage 10 Ta = +25 °C VCC = 16 V (MB3875) VCC = 19 V (MB3877) VREF = 0 mA 10 Ambient temperature Ta (°C) CTL pin current vs. CTL pin voltage Ta = +25 °C VCC = 16 V (MB3875) VCC = 19 V (MB3877) Reference voltage VREF (V) CTL pin current ICTL (µA) 8 6 4 2 8 6 4 2 0 0 5 10 15 20 25 0 0 5 10 15 20 25 CTL pin voltage VCTL(V) Control pin voltage VCTL (V) (Continued) 10 MB3875/3877 (Continued) Triangular wave oscillator frequency fOSC(kHz) Triangular wave oscillator frequency vs. timing resistor 1M Ta = +25 °C VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V Triangular wave oscillator frequency fOSC(Hz) Triangular wave oscillator frequency vs. power supply voltage 350 340 330 320 310 300 290 280 270 260 250 0 5 10 15 20 25 Ta = +25 °C CTL = 5 V RT = 47 kΩ 100 k 10 k 10 k 100 k 1M Timing resistor RT (Ω) Power supply voltage VCC (V) Triangular wave oscillator frequency vs. ambient temperature Triangular wave oscillator frequency fOSC(kHz) 350 340 330 320 310 300 290 280 270 260 250 −40 −20 0 20 40 60 80 100 Error amplifier threshold voltage vs. ambient temperature Error amplifier threshold voltage ∆VTH(%) 5.0 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 VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V VCC = 16 V (MB3875) VCC = 19 V (MB3877) CTL = 5 V RT = 47 kΩ Ambient temperature Ta (°C) Ambient temperature Ta (°C) 11 MB3875/3877 (Continued) Error amplifier gain and phase vs. frequency 40 φ Ta = +25 °C AV 180 4.2 V 90 VCC = 16 V (MB3875) VCC = 19 V (MB3877) Gain AV (dB) Phase φ (deg) 20 240 kΩ 0 −20 −40 100 1k 10 k 100 k 1M 0 −90 −180 10 M IN −+ 10 kΩ 2.4 kΩ 11 (6) − 9 (3) OUT 10 kΩ 8+ (7) 2.088 V Frequency f (Hz) Current detection amplifier gain and phase vs. frequency Ta = +25 °C AV VCC = 16 V (MB3875) VCC = 19 V (MB3877) 40 180 Gain AV (dB) Phase φ (deg) 20 90 24 (13) 0.1 V + × 25 − 0 −20 −40 100 1k φ 0 −90 −180 10 k 100 k 1M ∗ 1 (12) 100 kΩ 4 (10) OUT Current Amp.2 (Current Amp.1) ∗ : MB3875 12.6 V MB3877 16.8 V Frequency f (Hz) Power dissipation vs. ambient temperature Power dissipation PD (mW) 800 740 700 600 500 400 300 200 100 0 −40 −20 0 20 40 60 80 100 Ambient temperature Ta (°C) 12 MB3875/3877 s 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 µA 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 s 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 × I1 (A) × RS (Ω) s 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 × CS (µF) : s 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 (kΩ) : 15 MB3875/3877 s 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 × − INE1 − INE1 setting voltage range : 1.176 V to 4.2 V (equivalent to 7 V to 25 V for Vcc) −INE1 11 VCC R1 R2 A +INE1 8 − + s 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 Constant voltage control Constant current control AC adapter dynamicallycontrolled charging 16 MB3875/3877 s 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) ∗ OUT 20 D A B ∗ D I1 BATT RS 12.6 V/16.8 V ∗ 19 VH D Battery 1 17 MB3875/3877 s APPLICATION EXAMPLE ∗2 R5 330 kΩ R6 68 kΩ R4 −INE1 11 R10 22 kΩ OUTC1 C10 3900 pF 10 +INC1 + 13 × 25 −INC1 R11 − 12 30 kΩ 150 kΩ R9 8 +INE1 FB1 −INE2 R8 C8 3900 pF 150 kΩ R7 100 kΩ OUTC2 9 6 VREF − + + + + − VREF − + OUT Drive 20 Q1 L1 27 µH VCC Bias voltage block 21 VCC (O) + − C5 0.1 µF C1 22 µF A RS B BATT ∗4 R12 22 kΩ R14 1.3 kΩ R16 200 kΩ Q2 +INE2 30 kΩ R13 19 (VCC − 5 V) VH D1 − − 7 3 FB2 110 Ω R15 IN3 SW1 2 VIN ∗3 −INE3 C6 3900 pF 200 kΩ R3 FB3 15 16 VCC ∗1 50 kΩ VREF − + + (VCC UVLO) 215 kΩ + − 35 kΩ VREF (4.2 V) VREF 1 µA 2.5 V 1.5 V (45 pF) RT RT 17 VREF 47 kΩ 5 bias 0.91 V (0.77 V) VREF ULVO VCC CS 22 CS 2200 pF VCC 18 CTL C7 0.1 µF 14 GND 23 ∗ 1 : MB3875 MB3877 ∗ 2 : Vin = 16 V Vin = 19 V ∗ 3 : MB3875 MB3877 ∗ 4 : MB3875 MB3877 C9 0.1 µF 100 kΩ 150 kΩ 0Ω 82 kΩ 16 V/19 V 19 V 12.6 V 16.8 V 18 Battery 4 +INC2 + A 24 × 25 −INC2 − B 1 0.033 Ω C3 C2 100 µF 100 µF + + MB3875/3877 s PARTS LIST COMPONET QI Q2 D1 L1 C1 C2 C3 CS C5 C6 C7 C8 C9 C10 RS RT R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 ITEM FET FET Diode Coil OS Condensor OS Condensor OS Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Ceramics Condensor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor SPECIFICATION Si4435DY 2N7002 MBRS130LT3 27µH 22µF 100µF 100µF 2200pF 0.1µF 3900pF 0.1pF 3900pF 0.1µF 3900pF 0.033Ω 47kΩ 200kΩ 0Ω 82kΩ 330kΩ 68kΩ 150kΩ 100kΩ 150kΩ 22kΩ 30kΩ 22kΩ 30kΩ 1.3kΩ 110Ω 200kΩ 3.4A, 34mΩ 25V(10%) 16V(10%) 25V(10%) 16V(10%) 25V(10%) 10% 16V 10% 25V 10% 16V 10% 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% VENDOR VISHAY SILICONIX VISHAY SILICONIX PARTS NO. Si4435DY 2N7002 MBRS130LT3 CDRH127-27uH MOTOROLA SUMIDA — — — — Note: VISHAY SILICONIX : VISHAY Intertechrology, Inc. MOTOROLA : Motorola Japan Ltd. SUMIDA : SUMIDA ELECTRIC CO., Ltd. 19 MB3875/3877 s REFERENCE DATA • MB3875 Conversion efficiency vs. charge current (Fixed voltage mode) 100 Conversion efficiency vs. charge voltage (Fixed current mode) 100 Conversion efficiency η(%) Conversion efficiency η(%) 98 96 94 92 90 88 86 84 82 80 10 m BATT charge voltage=12.6V fOSC=288.78kHz efficiency η(%)=(VBATT × IBATT)/(Vin × Iin) × 100 Vin = 16 V Vin = 19 V 98 96 94 92 90 88 86 84 82 80 0 2 4 6 Vin = 16 V R4 = 0 Ω BATT= Electronic load (Product of KIKUSUI PLZ-150W) Vin = 19 V R4 = 82 kΩ 8 10 12 14 16 100 m 1 10 BATT charge current IBATT(A) BATT charge voltage VBATT(V) BATT voltage vs. BATT charge current 18 BATT voltage vs. BATT charge current 18 16 BATT voltage VBATT(V) 14 12 10 8 6 4 2 0 0 1 Dead Battery MODE (Product of KIKUSUI PLZ-150W) BATT voltage VBATT(V) Vin=16v BATT: Electronic load 16 14 12 10 8 6 4 2 0 0 1 Dead Battery MODE Vin=19v BATT: Electronic load (Product of KIKUSUI PLZ-150W) DCC MODE DCC MODE DCC : Dynamically-Controlled Charging 2 3 4 5 DCC : Dynamically-Controlled Charging 2 3 4 5 BATT charge current IBATT(A) BATT charge current IBATT(A) Note: KIKUSUI : KIKUSUI Electronics Corp. 20 MB3875/3877 (Continued) Soft-start operating waveforms Vin = 16 V Load: BATT = 20 Ω − INE1 = 0 V BATT (V) 20 15 CTL (V) 20 15 10 5 0 5V 0 40 80 120 20 ms 160 200 t (ms) 10 5 0 5V OUT (V) 20 15 10 5 0 −5 0 2 4 6 8 10 t (µs) 5V DC/DC converter switching waveforms Vin = 16 V FOSC = 288.8 kHz Load: BATT = 2A 1 µs Soft-start operating waveforms Vin = 19 V Load: BATT = 20 Ω − INE1 = 0 V BATT (V) 20 15 CTL (V) 20 15 10 5 0 5V 0 40 80 120 20 ms 160 200 t (ms) 10 5 0 5V DC/DC converter switching waveforms Vin = 19 V FOSC = 288.8 kHz Load: BATT = 2A 5V OUT (V) 20 15 10 5 0 −5 0 2 4 6 1 µs 8 10 t (µs) 21 MB3875/3877 • MB3877 Conversion efficiency vs.charge current Conversion efficiency vs. charge voltage 100 Conversion efficiency η(%) 98 96 94 92 90 88 86 84 82 80 10 m BATT charge voltage=12.6V fOSC=288.78kHz efficiency η(%)=(VBATT × IBATT)/(Vin × Iin) × 100 100 Conversion efficiency η(%) 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 BATT= Electronic load (Product of KIKUSUI PLZ-150W) Vin = 19 V Vin = 19 V R4 = 82 kΩ 100 m 1 10 10 12 14 16 18 BATT charge current IBATT(A) BATT charge voltage VBATT(V) BATT voltage vs. BATT charge current 20 18 BATT voltage VBATT(V) 16 14 12 10 8 6 4 2 0 0 1 Dead Battery MODE Vin=19v BATT: Electronic load (Product of KIKUSUI PLZ-150W) DCC MODE DCC : Dynamically-Controlled Charging 2 3 4 5 BATT charge current IBATT(A) Note: KIKUSUI : KIKUSUI Electronics Corp. 22 MB3875/3877 (Continued) Soft-start operating waveforms Vin = 19 V Load: BATT = 50 Ω − INE1 = 0 V 10 V BATT (V) 20 CTL (V) 20 10 15 10 5 0 5V 0 40 80 120 20 ms 160 200 t (ms) 0 DC/DC converter switching waveforms Vin = 19 V FOSC = 287.4 kHz Load: BATT = 2 A 5V OUT (V) 20 15 10 5 0 −5 0 2 4 6 1 µs 8 10 t (µs) 23 MB3875/3877 s 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 kΩ to 1 MΩ 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. s ORDERING INFORMATION Part number MB3875PFV MB3877PFV Package 24-pin plastic SSOP (FPT-24P-M03) Remarks 24 MB3875/3877 s PACKAGE DIMENSION 24-pin plastic SSOP (FPT-24P-M03) 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. 0.17±0.03 (.007±.001) 13 *17.75±0.10(.305±.004) 24 *2 5.60±0.10 INDEX 7.60±0.20 (.220±.004) (.299±.008) Details of "A" part 1.25 –0.10 .049 –.004 +0.20 +.008 (Mounting height) 0.25(.010) 0~8˚ 1 12 "A" M 0.65(.026) 0.24 .009 +0.08 –0.07 +.003 –.003 0.13(.005) 0.50±0.20 (.020±.008) 0.60±0.15 (.024±.006) 0.10±0.10 (.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 FUJITSU LIMITED 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, such as descriptions of function and application circuit examples, in this document are presented solely for the purpose of reference to show examples of operations and uses of Fujitsu semiconductor device; Fujitsu does not warrant proper operation of the device with respect to use based on such information. When you develop equipment incorporating the device based on such information, you must assume any responsibility arising out of such use of the information. Fujitsu assumes no liability for any damages whatsoever arising out of the use of the information. Any information in this document, including descriptions of function and schematic diagrams, shall not be construed as license of the use or exercise of any intellectual property right, such as patent right or copyright, or any other right of Fujitsu or any third party or does Fujitsu warrant non-infringement of any third-party’s intellectual property right or other right by using such information. Fujitsu assumes no liability for any infringement of the intellectual property rights or other rights of third parties which would result from the use of information contained herein. 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 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. 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. F0308 © FUJITSU LIMITED Printed in Japan