ds04-27704-2e fujitsu semiconductor data sheet assp for power supply applications (lithium ion battery charger) dc/dc converter ic for parallel charging MB3874/mb3876 n 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 batterys 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. n features ? detecting a voltage drop in the ac adapter and dynamically controlling the charge current (dynamically-con- trolled 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) n pac k ag e 24-pin plastic ssop (fpt-24p-m03)
MB3874/mb3876 2 (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 v cc ? built-in standby current function : 0 m 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
MB3874/mb3876 3 n pin assignment (top view) (fpt-24p-m03) 1 2 3 4 5 6 7 8 9 10 11 12 - inc1 : fb2 : - ine2 : + ine2 : vref : ctl : fb1 : - ine1 : + ine3 : - ine3 : fb3 : - inc2 : 24 23 22 21 20 19 18 17 16 15 14 13 : + inc1 : gnd : cs : v cc : out : vh : outm : rt : - ine4 : fb4 : - ine5 : + inc2
MB3874/mb3876 4 n pin description pin no. symbol i/o descriptions 1 Cinc1 i output voltage feedback input pin. 2 fb2 o error amplifier (error amp. 2) output pin. 3 Cine2 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. 6ctl 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. 8Cine1 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 Cine3 i error amplifier (error amp. 3) inverted input pin. 11 fb3 o error amplifier (error amp. 3) output pin. 12 Cinc2 i output voltage feedback input pin. 13 +inc2 i current detection amplifier (current amp. 2) input pin . 14 Cine5 i error amplifier (error amp. 5) inverted input pin. 15 fb4 o error amplifier (error amp. 4, 5) output pin. 16 Cine4 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 v cc 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 5 + - - + 24 1 4 + - - + 10 13 12 9 25 25 + + + + - 11 20 21 19 - + + + - 14 22 17 5 23 6 18 vref - + vref v cc vref vref - + + vref vref vref (4.2 v) r1 * r1 * r2 50 k w r2 50 k w 100 k w 100 k w 42 k w 208 k w 1 m a 15 2.5 v 2.5 v 1.5 v [ drive v cc (v cc - 5 v) (v cc uvlo) v cc ctl 215 k w 35 k w 0.91 v (0.77 v) vref ulvo bias - inc2 fb3 - ine3 fb2 vref + ine3 + ine2 - ine2 - ine1 fb1 - inc1 + inc2 gnd cs v cc v cc out outm vh rt - ine5 - ine4 fb4 + inc1 MB3874 100 k w mb3876 150 k w * : (45 pf) + - 16 2 3 7 8 n block diagram bias voltage block
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MB3874/mb3876 6 n absolute maximum ratings *: 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. n recommended operating conditions warning: the recommended operating conditions are required in order to ensure the normal operation of the semiconductor device. all of the devices 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. parameter symbol conditions rating unit min. max. power supply voltage v cc 28v output terminal current i out 60ma peak output current i out duty 5% (t =1 / f osc duty) 500 ma outm terminal output voltage v outm 17v power dissipation p d ta +25 c 740* mw storage temperature tstg C55 +125 c parameter symbol conditions value unit min. typ. max. power supply voltage v cc 725v reference voltage output current i ref C10ma vh pin output current i vh 030ma input voltage v -inc Cinc1, Cinc2 0 17 v v ine Cine1 to Cine5, +ine2 0 v cc C 1.8 v v +inc +inc1, +inc2 0 v cc v ctl pin input voltage v ctl 025v output current i out out pin C45 45 ma peak output current i out duty 5% (t =1 / f osc duty) C450 450 ma outm pin output voltage v outm 315v outm pin output current i outm 1ma oscillator frequency f osc 100 290 500 khz timing resistor r t 33 47 130 k w soft-start capacitor c s 2200 100000 pf vh pin capacitor c vh 0.11.0 m f reference voltage output capacitor c ref 0.11.0 m f operating ambient temperature ta C30 +25 +85 c
MB3874/mb3876 7 n electrical characteristics (MB3874 : ta = +25 c, v cc = 16 v, vref = 0 ma) (mb3876 : ta = +25 c, v cc = 19 v, vref = 0 ma) *: standard design value. (continued) parameter symbol pin no. conditions value unit remarks min. typ. max. output voltage v ref 5 ta = +25c 4.167 4.200 4.233 v ta = C30c to +85c 4.158 4.200 4.242 v input stability line 5 v cc = 7 v to 25 v 3 10 mv load stability load 5 vref = 0 ma to C1 ma 1 10 mv short-circuit output current i os 5 vref = 1 v C25 C15 C5 ma threshold voltage v tlh 21 v cc = 6.3 6.6 6.9 v v thl v cc = 5.3 5.6 5.9 v hysteresis width v h 21 0.7 1.0 1.3 v threshold voltage v tlh 5 vref = 2.6 2.8 3.0 v v thl vref= 2.4 2.6 2.8 v hysteresis width v h 5 0.05 0.20 0.35 v charge current i cs 22 C1.3 C0.8 C0.5 m a oscillation frequency f osc 20 rt = 47 k w 260 290 320 khz frequency tem- perature stability d f/fdt 20 ta = C30c to +85c 1* % reference voltage block (ref) under voltage lockout protection circuit block (uvlo) soft-start block (soft) triangular waveform oscillator circuit block (osc)
MB3874/mb3876 8 (continued) (MB3874 : ta = +25 c, v cc = 16 v, vref = 0 ma) (mb3876 : ta = +25 c, v cc = 19 v, vref = 0 ma) *: standard design value. (continued) parameter symbol pin no conditions value unit remarks min. typ. max. threshold voltage v th 21 fb1 = 2 v, Cine1 = 2.35 v 14.00 14.20 14.40 v MB3874 fb1 = 2 v, Cine1 = 2.83 v 16.80 17.10 17.40 v mb3876 input pin current i in 8 Cine1= 0 v C100 C30 na voltage gain a v 7 dc 100* db frequency bandwidth bw 7 av = 0 db 2.0* mhz output voltage v fbh 73.94.1v v fbl 7 20 200 mv output source current i source 7 fb1 = 2 v C2.0 C0.6 ma output sink current i sink 7 fb1 = 2 v 150 300 m a input offset voltage v io 3,4 9,10 fb2 = fb3 = 2 v 1* mv input pin current i ine 4,9 +ine2 = +ine3 = 0 v C100 C30 na common mode input voltage range v cm 3,4 9,10 0v cc C1.8 v voltage gain a v 2, 11 dc 100* db frequency bandwidth bw 2, 11 a v = 0 db 2.0* mhz output voltage v fbh 2, 11 3.9 4.1 v v fbl 2, 11 20 200 mv output source current i source 2, 11 fb2 = fb3 = 2 v C2.0 C0.6 ma output sink current i sink 2, 11 fb2 = fb3 = 2 v 150 300 m a error amplifier block (error amp.1) error amplifier block (error amp.2, 3)
MB3874/mb3876 9 (continued) (MB3874 : ta = +25 c, v cc = 16 v, vref = 0 ma) (mb3876 : ta = +25 c, v cc = 19 v, vref = 0 ma) *: standard design value. (continued) parameter symbol pin no conditions value unit remarks min. typ. max. threshold voltage v th 1, 12 fb4 = 2 v, ta = +25 c 12.500 12.600 12.700 v MB3874 16.666 16.800 16.934 v mb3876 fb1 = 2 v, ta = C30 c to +85 c 12.474 12.600 12.726 v MB3874 16.632 16.800 16.968 v mb3876 input current i ineh 1, 12 Cinc1 = Cinc2 = 12.6 v 84 150 m a MB3874 Cinc1 = Cinc2 = 16.8 v 84 150 m a mb3876 i inel 1, 12 v cc = 0 v, Cinc1 = Cinc2 = 12.6 v 0 1 m a MB3874 v cc = 0 v, Cinc1 = Cinc2 = 16.8 v 0 1 m a mb3876 input resistor r 1 1, 12 70 100 130 k w MB3874 105 150 195 k w mb3876 r 2 14, 16 355065k w voltage gain a v 15 dc 100* db frequency bandwidth bw 15 av = 0 db 2.0* mhz output voltage v fbh 15 3.9 4.1 v v fbl 15 20 200 mv output source current i source 15 fb4 = 2 v C2.0 C0.6 ma output sink current i sink 15 fb4 = 2 v 150 300 m a error amplifier block (current amp.4, 5)
MB3874/mb3876 10 (continued) (MB3874 : ta = +25 c, v cc = 16 v, vref = 0 ma) (mb3876 : ta = +25 c, v cc = 19 v, vref = 0 ma) (continued) parameter symbol pin no. conditions value unit remarks min. typ. max. input current i +inch 13, 24 +inc1= +inc2=12.7 v, Cinc1= Cinc2=12.6 v 1020 m a MB3874 +inc1= +inc2=16.9 v, Cinc1= Cinc2=16.8 v 1020 m a mb3876 i +incl 13, 24 +inc1= +inc2= 0.1 v, Cinc1= Cinc2= 0 v C130 C65 m a current detection voltage v -ine1 3, 10 +inc1= +inc2=12.7 v, Cinc1= Cinc2=12.6 v 2.25 2.50 2.75 v MB3874 +inc1= +inc2=16.9 v, Cinc1= Cinc2=16.8 v 2.25 2.50 2.75 v mb3876 v -ine2 3, 10 +inc1= +inc2=12.63v, Cinc1= Cinc2=12.6 v 0.50 0.75 1.00 v MB3874 +inc1= +inc2=16.83 v, Cinc1= Cinc2=16.8 v 0.50 0.75 1.00 v mb3876 v -ine3 3, 10 +inc1= +inc2= 0.1 v , Cinc1= Cinc2= 0 v 1.25 2.50 3.75 v v -ine4 3, 10 +inc1= +inc2= 0.03 v, Cinc1= Cinc2= 0 v 0.125 0.750 1.375 v common mode input voltage range v cm 1, 12, 13, 24 0v cc v voltage gain a v 3, 10 +inc1= +inc2=12.7 v, Cinc1= Cinc2=12.6 v 22.5 25 27.5 v/v MB3874 +inc1= +inc2=16.9 v, Cinc1= Cinc2=16.8 v 22.5 25 27.5 v/v mb3876 output voltage v outch 3, 10 3.9 4.1 v v outcl 3, 10 20 200 mv pwm comparator block (pwm comp.) threshold voltage v tl 2, 7, 11, 15 duty cycle = 0 % 1.4 1.5 v v th 2, 7, 11, 15 duty cycle = 100 % 2.5 2.6 v threshold voltage v tlh 18 fb1 = 2.7 2.8 2.9 v v thl 18 fb1 = 2.4 2.5 2.6 v hysteresis width v h 18 0.2 0.3 0.4 v output leak current i leak 18 outm = 5 v 0 1 m a output voltage v ol 18 outm = 1 ma 0.15 0.4 v current detection amplifier block (current amp.1, 2) constant power detection block (mask comp.)
MB3874/mb3876 11 (continued) (MB3874 : ta = +25 c, v cc = 16 v, vref = 0 ma) (mb3876 : ta = +25 c, v cc = 19 v, vref = 0 ma) *: standard design value parameter symbol pin no. conditions value unit remarks min. typ. max. output source current i source 20 out = 11 v, duty 5 % (t = 1/fosc duty ) C200* ma MB3874 out = 14 v, duty 5 % (t = 1/fosc duty ) C200* ma mb3876 output sink current i sink 20 out = 16 v, duty 5 % (t = 1/fosc duty ) 200* ma MB3874 out = 19 v, duty 5 % (t = 1/fosc duty ) 200* ma mb3876 output on resistor r oh 20 out = - 45 ma 8.0 16.0 w r ol 20 out = 45 ma 6.5 13.0 w rise time tr1 20 out = 3300 pf (equivalent to si4435dy) 70*ns fall time tf1 20 out = 3300 pf (equivalent to si4435dy) 60*ns ctl input voltage v on 6 active mode 2.0 25.0 v v off 6 standby mode 00.8v input current i ctlh 6 ctl = 5 v 100 200 m a i ctll 6 ctl = 0 v 0 1 m a output voltage vh 19 v cc = 7 v to 25 v, vh = 0 to 30 ma v cc C 5.5 v cc C 5.0 v cc C 4.5 v standby current i ccs 21 ctl = 0 v 010 m a power supply current i cc 21 ctl = 5 v 6.09.0ma MB3874 6.59.5ma mb3876 output block (out) control block (ctl) bias voltage block (vh) general
MB3874/mb3876 12 n typical characteristics (continued) 10 8 6 4 2 0 0 5 10 15 20 25 ta = + 25 c v cc = 16 v (MB3874) v cc = 19 v (mb3876) vref = 0 ma power supply current i cc (ma) power supply voltage v cc (v) power supply current vs. power supply voltage power supply voltage v cc (v) reference voltage vs. power supply voltage reference voltage v ref (v) reference voltage v ref (v) reference voltage vs. vref load current reference voltage vs. ctl pin voltage reference voltage v ref (v) ctl pin voltage v ctl (v) ctl pin voltage v ctl (v) ctl pin current vs. ctl pin voltage ctl pin current i ctl ( m a) 10 8 6 4 2 0 0 5 10 15 20 25 ta = + 25 c ctl = 5 v ta = + 25 c ctl = 5 v vref = 0 ma 10 8 6 4 2 0 0 5 10 15 20 25 10 8 6 4 2 0 0 5 10 15 20 25 30 ta = + 25 c v cc = 16 v (MB3874) v cc = 19 v (mb3876) ctl = 5 v 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 v cc = 16 v (MB3874) v cc = 19 v (mb3876) ctl = 5 v vref = 0 ma 1.0 0.8 0.6 0.4 0.2 0.0 0 5 10 15 20 25 ta = + 25 c v cc = 16 v (MB3874) v cc = 19 v (mb3876) reference voltage vs. ambient temperature reference voltage d v ref (%) ambient temperature ta ( c) vref load current i ref (ma)
MB3874/mb3876 13 (continued) 1 m 100 k 10 k 10 k 100 k 1 m ta = + 25 c v cc = 16 v (MB3874) v cc = 19 v (mb3876) ctl = 5 v 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 k w triangular wave oscillator frequency vs. timing resistor triangular wave oscillator frequency f osc (hz) timing resistor r t ( w ) triangular wave oscillator frequency f osc (khz) triangular wave oscillator frequency vs. power supply voltage power supply voltage v cc (v) ambient temperature ta ( c) 350 340 330 320 310 300 290 280 270 260 250 - 40 - 20 0 20 40 60 80 100 v cc = 16 v (MB3874) v cc = 19 v (mb3876) ctl = 5 v rt = 47 k w 5.0 4.0 3.0 2.0 1.0 0.0 - 40 - 20 0 20 40 60 80 100 - 1.0 - 2.0 - 3.0 - 4.0 - 5.0 v cc = 16 v (MB3874) v cc = 19 v (mb3876) ctl = 5 v triangular wave oscillator frequency vs. ambient temperature triangular wave oscillator frequency f osc (khz) error amplifier threshold voltage vs. ambient temperature error amplifier threshold voltage d v th (%) ambient temperature ta ( c)
MB3874/mb3876 14 (continued) power dissipation vs. ambient temperature power dissipation p d (mw) ambient temperature ta ( c) error amplifier gain and phase vs. frequency gain a v (db) frequency f (hz) current detection amplifier gain and phase vs. frequency gain a v (db) frequency f (hz) ta = + 25 c f a v 40 20 0 - 20 - 40 100 1 k 10 k 100 k 1 m 10 m 180 90 0 - 90 - 180 v cc = 16 v (MB3874) v cc = 19 v (mb3876) - + - + 4 (9) (11) (10) 2.088 v 3 10 k w 2.4 k w 240 k w 10 k w 4.2 v 2 out in 1 m f error amp.2 (error amp.3) phase f (deg) + - 1 24 3 (13) (12) (10) 100 k w out 25 0.1 v * : MB3874 12.6 v mb3876 16.8 v current amp.1 (current amp.2) v cc = 16 v (MB3874) v cc = 19 v (mb3876) 40 20 0 100 1 k 10 k 100 k 1 m - 20 - 40 180 90 0 - 90 - 180 ta = + 25 c a v f in * phase f (deg) 800 740 700 600 500 400 300 200 100 0 - 40 - 20 0 20 40 60 80 100
MB3874/mb3876 15 n 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 temper- ature-compensated, stable voltage ( : = 4.2 v) used as the reference supply voltage for the ics 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
MB3874/mb3876 16 (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 m 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.
MB3874/mb3876 17 n 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 i1 (a) r s 1 ( w ) battery 2 charge current setting voltage : +ine3 +ine3 (v) = 25 i2 (a) r s 2 ( w ) n 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 c s ( m f) n method of setting the triangular wave oscillator frequency setting the trianguar wave oscillator frequency can be set by the timing resistor (r t ) connected the rt terminal (pin 17). triangular wave oscillator frequency f osc f osc (khz) : = 14444 / r t (k w ) n ac adapter voltage detection when partial potential point a of the ac adapter voltage (vcc) becomes lower than the voltage at the Cine1 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 - ine1 : = 5.95 - ine1 - ine1 setting voltage range : 1.176 v to 4.2 v (equivalent to 7 v to 25 v for vcc) - + 8 v cc 208 k w - ine1 a 42 k w
MB3874/mb3876 18 n operation timing diagram 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 2.8 v 2.5 v 1.5 v err amp.2 , 3 err amp.4 , 5 err amp.1 fb2,3 fb4 fb1 out outm constant voltage control ac adapter dynamically- controlled charging constant current control ac adapter dynamically- controlled charging battery charger MB3874 mb3876 mode signal system power v in ac adaptor battery ichg isys
MB3874/mb3876 19 n 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 (rs 1 , rs 2 ) pay attention to the voltage/current characteristics of the reverse-current preventive diode (d1, d2) not to let it exceed the overcharge stop voltage. v cc out vin (16 v/19 v) vh i1 r s1 batt1 12.6 v/16.8 v 20 21 19 a b d1 i2 r s2 batt2 12.6 v/16.8 v c d d2 to 24 pin to 1 pin battery 1 to 12 pin to 13 pin battery 2
MB3874/mb3876 20 n application example + - - + 24 1 4 + - - + 10 13 12 c d 9 25 25 + + + + - 11 20 21 19 - + + + - 14 22 17 5 23 6 18 vref - + vref v cc vref vref - + + vref vref vref (4.2 v) * 1 * 3 * 1 50 k w c5 3900 pf c6 3900 pf 3900 pf r3 200 k w r7 150 k w r17 22 k w r18 200 k w r6 330 k w r15 5.6 k w 33 k w r13 r4 200 k w c s 2200 pf 50 k w 100 k w 100 k w 42 k w 208 k w 1 m a 15 2.5 v 2.5 v (2.8 v) 1.5 v [ drive v cc (v cc - 5 v) (v cc uvlo) v cc ctl 215 k w 35 k w 47 k w 0.91 v (0.77 v) vref ulvo bias - inc2 fb3 - ine3 fb2 vref + ine3 + ine2 - ine2 - ine1 fb1 - inc1 + inc2 vin sw2 gnd cs v cc v cc out outm vh rt r t - ine5 - ine4 fb4 + inc1 MB3874 100 k w mb3876 150 k w MB3874 22 k w mb3876 15 k w MB3874 16 v mb3876 19 v MB3874 12.6 v mb3876 16.8 v * 1 : * 2 : * 3 : * 4 : (45 pf) + - 16 2 3 7 8 c7 0.1 m f c12 a b 3900 pf 6800 pf r9 150 k w r8 47 k w r11 30 k w r10 * 2 r16 22 k w r19 200 k w r14 5.6 k w 33 k w r12 sw1 c9 c8 0.1 m f c13 q2 q3 l1 i1 r s1 batt1 * 4 a b d2 i2 d3 r s2 batt2 * 4 c d d1 + - 0.075 w 0.075 w c1 22 m f c14 0.1 m f c10 0.1 m f c2 22 m f c4 100 m f 27 m h c3 100 m f q1 + + - - + - bias voltage block pin 24 pin 1 battery 1 pin 13 pin 12 battery 2
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MB3874/mb3876 21 n parts list note: vishay siliconix : vishay intertechnology, inc. motorola : motorola japan ltd. rohm : rhom co., ltd sumida : sumida electric co., ltd. 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 m h 2.8 a, 80 m w sumida cdrh127-27 m h c1, c2 c3, c4 c5, c6 c7 c8 c9 c10 c s c12, c13 c14 os condensor os condensor ceramics condensor ceramics condensor ceramics condensor ceramics condensor ceramics condensor ceramics condensor ceramics condensor ceramics condensor 22 m f 100 m f 3900 pf 3900 pf 6800 pf 3900 pf 0.1 m f 2200 m f 0.1 m f 0.1 m 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 r t 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 w 200 k w 47 k w 330 k w 150 k w 47 k w 150 k w 22 k w 30 k w 30 k w 5.6 k w 22 k w 200 k w 1.0 % 1.0 % 1.0 % 5 % 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 0.5 % 0.5 % 5 %
MB3874/mb3876 22 n reference data ? MB3874 note: kikusui : kikusui electronics corp. vin = 16 v 10 m 100 m 1 10 100 98 96 94 92 90 88 86 84 82 80 vin = 16 v r10 = 22 k w 100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 10121416 dead battery mode dcc mode dcc : dynamically-controlled charging 0.0 18 16 14 12 10 8 6 4 2 0 0.4 0.2 0.8 0.6 1.2 1.0 1.6 1.4 2.0 1.8 dead battery mode dcc mode dcc : dynamically-controlled charging 0.0 18 16 14 12 10 8 6 4 2 0 0.4 0.2 0.8 0.6 1.2 1.0 1.6 1.4 2.0 1.8 conversion efficiency vs. charge current (fixed voltage mode) conversion efficiency vs. charge voltage (fixed current mode) batt1 charge current i batt1 (a) conversion efficiency h( %) conversion effciency h( %) batt1 charge voltage v batt1 (v) batt voltage vs. batt charge current batt voltage vs. batt charge current batt1 voltage v batt1 (v) batt1 voltage v batt1 (v) batt1 charge current i batt1 (a) batt1 charge current i batt1 (a) vin = 16v, batt2= open, batt1 : electronic load, (product of kikusui plz-150w) paralle charging, vin = 16v, batt1 : electronic load, (product of kikusui plz-150w), i batti =i batt2 batt1 charge voltage = 12.6v, f osc = 286.37khz, batt2 = open h( %)=( v batt1 i batt1 )/( v in iin) 100 batt2= open, batt1: electronic load, (product of kikusui plz-150w) batt1 charge current i batt1 (a) batt1 charge voltage v batt1 (v) conversion efficiency h( %) conversion effciency h( %) vin = 16 v 10 m 100 m 1 10 100 98 96 94 92 90 88 86 84 82 80 vin = 16 v r10 = 22 k w 100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 10121416 conversion efficiency vs. charge current (fixed voltage mode) conversion efficiency vs. charge voltage (fixed current mode) paralle charging, batt1 charge voltage = 12.6v f osc = 286.37khz h( %)=((v batt1 i batt1 )+(v batt2 i batt2 ))/(vin iin) 100 i batti = i batt2 paralle charging, batt1: electronic load, (product of kikusui plz-150w), i batti = i batt2
MB3874/mb3876 23 (continued) 20 15 10 5 0 20 15 10 5 0 0 80 120 160 200 t (ms) 40 batt1 (v) ctl (v) 5 v 5 v 20 ms 20 15 046810 t ( m s) 2 10 5 0 - 5 out (v) 1 m s 5 v soft start operating waveforms vin = 16 v load : batt1 = 20 w - ine1 = 0 v batt2 = open dc/dc converter switching waveforms vin = 16 v f osc = 286.7 khz load : batt1 = 1a batt2 = open
MB3874/mb3876 24 ? mb3876 note: kikusui : kikusui electronics corp. vin = 19 v 10 m 100 m 1 10 100 98 96 94 92 90 88 86 84 82 80 vin = 19 v r10 = 15 k w 100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 1012141618 dead battery mode dcc mode dcc : dynamically-controlled charging 0.0 18 20 16 14 12 10 8 6 4 2 0 0.4 0.2 0.8 0.6 1.2 1.0 1.6 1.4 2.0 1.8 conversion efficiency vs.charge current (fixed voltage mode) batt1 charge current i batt1 (a) conversion efficiency h( %) batt1 charge voltage =16.8v, f osc = 282.71khz, batt2 = open, h( %)=(v batt1 i batt1 )/(vin iin) 100 conversion efficiency vs. charge voltage (fixed current mode) conversion efficiency h( %) batt1 charge voltage v batt1 (v) batt voltage vs. batt charge current batt1 voltage v batt1 (v) batt1 charge current i batt1 (a) vin = 19v, batt2 = open, batt1:electronic load, (product of kikusui plz-150w) batt1 charge current i batt1 (a) batt1 voltage v batt1 (v) dead battery mode dcc mode dcc : dynamically-controlled charging 0.0 18 20 16 14 12 10 8 6 4 2 0 0.4 0.2 0.8 0.6 1.2 1.0 1.6 1.4 2.0 1.8 batt voltage vs. batt charge current batt1 charge current i batt1 (a) conversion efficiency h( %) conversion efficiency h( %) vin = 19 v 10 m 100 m 1 10 100 98 96 94 92 90 88 86 84 82 80 vin = 19 v r10 = 15 k w 100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 1012141618 conversion efficiency vs.charge current (fixed voltage mode) conversion efficiency vs. charge voltage (fixed current mode) batt2 = open, batt1 : electronic load, (prouct of kikusui plz-150w) batt1 charge voltage v batt1 (v) parallel charging, batt1 charge voltage =16.8 v, f osc = 282.71 khz, h( %)=((v batt1 i batt1 )+(v batt2 i batt2 ))/(vin iin) 100, i batti = i batt2 parallel charging, batt1 : electronic load, (prouct of kikusui plz-150w), i batti = i batt2 parallel charging, vin = 19v, batt1: electronic load, (product of kikusui plz-150w), i batti = i batt2
MB3874/mb3876 25 (continued) 20 10 0 0 80 120 160 200 t (ms) 40 batt1 (v) 20 15 10 5 0 ctl (v) 10 v 5 v 20 ms 20 15 046810 t ( m s) 2 10 5 0 - 5 out (v) 1 m s 5 v soft start operating waveforms vin = 19 v load : batt1 = 50 w - ine1 = 0 v batt2 = open dc/dc converter switching waveforms vin = 19 v f osc = 282.6 khz load : batt1 = 1 a batt2 = open
MB3874/mb3876 26 n 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 elec- trical 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 imped- ance. 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 w to 1 m w between body and ground. 5. do not apply negative voltages. the use of negative voltages below C0.3 v may create parasitic transistors on lsi lines, which can cause abnormal operation n ordering information part number package remarks MB3874pfv mb3876pfv 24-pin plastic ssop (fpt-24p-m03)
MB3874/mb3876 27 n package dimension 24-pin plastic ssop (fpt-24p-m03) * : these dimensions do not include resin protrusi on. dimensions in: mm (inches) c 1994 fujitsu limited f24018s-2c-2 0.50?.20 (.020?008) 0.10?.10(.004?004) (stand off) 0 10 details of "a" part 7.75?.10(.305?004) 0.65?.12(.0256?0047) 7.15(.281)ref 6.60(.260) 5.60?.10 nom 7.60?.20 (.220?004) (.299?008) "a" .006 ?001 +.002 ?.02 +0.05 0.15 .049 ?004 +.008 ?.10 + 0 . 20 1.25 .009 ?002 +.004 ?.05 +0.10 0.22 0.10(.004) index * * (mounting height) c 1994 fujitsu limited f24018s-2c-2 0.50?.20 (.020?008) 0.10?.10(.004?004) (stand off) 0 10 details of "a" part 7.75?.10(.305?004) 0.65?.12(.0256?0047) 7.15(.281)ref 6.60(.260) 5.60?.10 nom 7.60?.20 (.220?004) (.299?008) "a" .006 ?001 +.002 ?.02 +0.05 0.15 .049 ?004 +.008 ?.10 +0.20 1.25 .009 ?002 +.004 ?.05 +0.10 0.22 0.10(.004) index * * (mounting height)
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.
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