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FUJITSU SEMICONDUCTOR DATA SHEET
DS04-27703-1E
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.
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) * High precision reference voltage source : 4.2 V 0.8 % (Continued)
s PACKAGE
24-pin plastic SSOP
(FPT-24P-M03)
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MB3875/MB3877
(Continued) * Support for frequency setting using an external resistor (Frequency setting capacitor integrated) :100 kHz to 500 kHz * On-chip current detector amplifier with wide in-phase input voltage range : 0 V to VCC * On-chip standby current function : 0 A (Typ.) * On-chip soft start function * Internal totem-pole output stage supporting P-channel MOS FETs devices
2
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MB3875/MB3877
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)
3
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MB3875/MB3877
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 .
4
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MB3875/MB3877
s BLOCK DIAGRAM
-INE1 11 OUTC1 +INC1 + x 25 -INC1 - 12 13 +INE1 FB1 -INE2 OUTC2 +INC2 -INC2 +INE2 8 9 6 4 24 1 7 3 10 VREF - + + + + - + x 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 k
(VCC UVLO) 215 k + - 35 k
FB3 15 VREF 1 A
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 k
MB3877 150 k
5
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MB3875/MB3877
s ABSOLUTE MAXIMUM RAGINGS
Parameter Power supply voltage Output current Peak output current Power dissipation Storage temperature Symbol VCC IOUT IOUT PD Tstg Ta +25C -- Conditions VCC,VCC(O) -- Duty 5% (t =1 / fOSC x 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 x 10 cm). WARNING: Semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.) in excess of absolute maximum ratings. Do not exceed these ratings.
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 x 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 k pF F F 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. 6
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MB3875/MB3877
s ELECTRICAL CHARACTERISTICS
(MB3875 : Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877 : Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Reference voltage block (Ref) Output voltage Input stability Load stability Short-circuit output current Threshold voltage Under voltage lockout protection circuit block (UVLO) VTHL Hysteresis width VH VTLH Threshold voltage VTHL Hysteresis width Triangular waveform Soft-start oscillator circuit block block (OSC) (SOFT) VH 5 5 VREF= -- 2.4 0.05 2.6 0.20 2.8 0.35 V V 18
Symbol Pin No.
Conditions Ta = +25C Ta = -30C to +85C 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
A
Oscillation frequency
fOSC
20
RT = 47 k
260
290
320
kHz
Frequency temperature stability
f/fdT
20
Ta = -30C to +85C
--
1*
--
%
*: Standard design value.
(Continued)
7
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MB3875/MB3877
(MB3875 : Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877 : Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter Input offset voltage Error amplifier block (Error Amp.1, 2) Input bias current 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 A V V V V A A A A k k k dB MHz V mV mA A
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)
8
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MB3875/MB3877
(MB3875 : Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0 mA) (MB3877 : Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0 mA) Parameter
Symbol Pin No.
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 dB -- -- 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 A MB3875 A MB3877 A MB3875 A MB3877 A A V V V V V V V V/V MB3875 V/V MB3877 MHz V mV mA A
MB3875 MB3877 MB3875 MB3877
I+INCH
13, 24
Input current
I-INCH
1, 12
I+INCL I-INCL Current detection amplifier block (Current Amp.1,2)
13, 24 1, 12
VOUTC1
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
BW VOUTCH VOUTCL
4, 10 4, 10 4, 10 4, 10 4, 10
Output source curISOURCE rent Output sink current *: Standard design value. ISINK
(Continued)
9
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MB3875/MB3877
(Continued)
(MB3875 : Ta = +25C, VCC = 16 V, VCC (O) = 16 V, VREF = 0mA) (MB3877 : Ta = +25C, VCC = 19 V, VCC (O) = 19 V, VREF = 0mA) 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 x Duty )
OUT = 14 V Duty 5 % OUT = 16 V Duty 5 %
--
-200*
--
mA MB3875
(t = 1/fosc x Duty ) Output block (OUT)
--
-200*
--
mA MB3877
Output sink current
ISINK
20
(t = 1/fosc x Duty )
OUT = 19 V Duty 5 %
--
200*
--
mA MB3875
(t = 1/fosc x 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 ns ns V V A A 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
A mA MB3875 mA MB3877
*: Standard design value.
10
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MB3875/MB3877
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 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
0
20
40
60
80
100
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 (A)
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)
11
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MB3875/MB3877
(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 waveoscillator 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 k
100 k
10 k 10 k
100 k
1M
Timing resistor RT () 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
Power supply voltage VCC (V) 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 k
Ambient temperature Ta (C)
Ambient temperature Ta (C)
12
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MB3875/MB3877
(Continued)
Error amplifier gain and phase vs. frequency
40 Ta = +25 C AV 180 4.2 V 90 VCC = 16 V (MB3875) VCC = 19 V (MB3877)
Phase (deg)
Gain AV (dB)
20
240 k IN
- @+
0 -20 -40 100 1k 10 k 100 k 1M
0 -90 -180 10 M
10 k 2.4 k
11 (6)
- 9 (3)
OUT
10 k
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 (deg)
20
90
24 (13) 0.1 V 1 (12)
+ x 25 -
0 -20 -40 100 1k
0 -90 -180 10 k 100 k 1M
100 k 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)
13
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MB3875/MB3877
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 -INC1 terminal (pin 1). Then it outputs the signal amplified by 25 times to the error amplifier (Error Amp. 2) at the next stage. 14
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MB3875/MB3877
(7) PWM comparator block (PWM Comp.) The PWM comparator circuit is a voltage-pulse width converter for controlling the output duty of the error amplifiers (Error Amp. 1 to Error Amp. 3) depending on their output voltage. The PWM comparator circuit compares the triangular wave generated by the triangular wave oscillator to the error amplifier output voltage and turns on the external output transistor during the interval in which the triangular wave voltage is lower than the error amplifier output voltage. (8) Output block (OUT) The output circuit uses a totem-pole configuration capable of driving an external P-channel MOS FET. The output "L" level sets the output amplitude to 5 V (typical) using the voltage generated by the bias voltage block (VH). This results in increasing conversion efficiency and suppressing the withstand voltage of the connected external transistor in a wide range of input voltages. (9) Control block (CTL) Setting the CTL terminal (pin 14) low places the IC in the standby mode. (The supply current is 10 A at maximum in the standby mode.) (10) Bias voltage block (VH) The bias voltage circuit outputs Vcc - 5 V (typical) as the minimum potential of the output circuit. In the standby mode, this circuit outputs the potential equal to Vcc.
2. Protection Functions
Low-Vcc malfunction preventive circuit (UVLO) The transient state or a momentary decrease in supply voltage or internal reference voltage (VREF), which occurs when the power supply is turned on, may cause malfunctions in the control IC, resulting in breakdown or degradation of the system. To prevent such malfunction, the low-Vcc malfunction preventive circuit detects a supply voltage or internal reference voltage drop and fixes the OUT terminal (pin 20) to the "H" level. The system restores voltage supply when the supply voltage or internal reference voltage reaches the threshold voltage of the low-Vcc malfunction preventive circuit.
3. Soft Start Function
Soft start block (SOFT) Connecting a capacitor to the CS terminal (pin 22) prevents surge currents when the IC is turned on. Using an error amplifier for soft start detection makes the soft start time constant, independent of the output load of the DC/DC converter.
15
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MB3875/MB3877
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 x I1 (A) x RS ()
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 (sec) = 4.2 x CS (F) :
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 (k) :
16
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MB3875/MB3877
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 x - 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.3 FB3 Error Amp.2 FB2 Error Amp.1 FB1
1.5 V
OUT
AC adapter dynamicallycontrolled charging
Constant voltage control
Constant current control
AC adapter dynamicallycontrolled charging
17
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MB3875/MB3877
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
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
18
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MB3875/MB3877
s APPLICATION EXAMPLE
2
R5 330 k R6 68 k
R4
-INE1 11 R10 22 k OUTC1 C10 3900 pF 10 +INC1 + 13 x 25 -INC1 R11 - 12 30 k 150 k R9 8 +INE1 FB1 -INE2 R8 C8 3900 pF 100 k OUTC2 9 6 4
VREF - + + + + - VREF - + OUT Drive 20 Q1 L1 27 H VCC
Bias voltage block
21
VCC (O)
+
C5 0.1 F
@
-
C1 22 F A RS B BATT 4
+INC2 24 150 k A R7 -INC2 B 1 R12 22 k +INE2 R14 7 1.3 k 30 k R16 R13 FB2 200 k 3 110 Q2 R15 IN3 2 SW1 VIN 3 -INE3 C6 3900 pF 200 k R3 FB3 15 16
+ -
+ -
19 (VCC - 5 V)
VH D1
@
@
VCC
1
50 k
VREF
- + +
(VCC UVLO) 215 k + - 35 k
VREF (4.2 V) VREF 1 A 2.5 V 1.5 V (45 pF) RT RT 17 VREF 47 k 5 bias
0.91 V (0.77 V) VREF ULVO VCC
CS 22 CS 2200 pF
VCC 18 CTL C7 0.1 F
14
GND
23
1 : MB3875
MB3877 2 : Vin = 16 V Vin = 19 V 3 : MB3875 MB3877 4 : MB3875 MB3877
C9 0.1 F
100 k 150 k 0 82 k 16 V/19 V 19 V 12.6 V 16.8 V
Battery
+ x 25 -
0.033 C3 C2 100 F 100 F
19
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MB3875/MB3877
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 27H 22F 100F 100F 2200pF 0.1F 3900pF 0.1pF 3900pF 0.1F 3900pF 0.033 47k 200k 0 82k 330k 68k 150k 100k 150k 22k 30k 22k 30k 1.3k 110 200k 3.4A, 34m 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
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Note: VISHAY SILICONIX : VISHAY Intertechrology, Inc. MOTOROLA : Motorola Japan Ltd. SUMIDA : SUMIDA ELECTRIC CO., Ltd.
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MB3875/MB3877
s REFERENCE DATA
* MB3875 Conversion efficiency vs. charge current (Fixed voltage mode)
100
Conversion efficiency vs. charge voltage (Fixed current mode)
100
Conversion efficiency (%)
Conversion effciency (%)
98 96 94 92 90 88 86 84 82 80 10 m
BATT charge voltage=12.6V fOSC=288.78kHz efficiency (%)=(VBATT x IBATT)/(Vin x Iin) x 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
BATT= Electronic load
(Product of KIKUSUI PLZ-150W)
Vin = 19 V R4 = 82 k
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)
BATT voltage VBATT(V)
Vin=16v BATT: Electronic load
(Product of KIKUSUI PLZ-150W)
16 14 12 10 8 6 4 2 0 0 1 Dead Battery MODE
Vin=19v BATT:Electronic load
(Product of KIKUSUI PLZ-150W)
14 12 10 8 6 4 2 0 0 1 Dead Battery MODE
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.
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MB3875/MB3877
(Continued)
Soft start operating waveforms
Vin = 16 V Load : BATT = 20 - 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 (s) 5V
DC/DC converter switching waveforms
Vin = 16 V FOSC = 288.8 kHz Load : BATT = 2A
1 s
Soft start operating waveforms
Vin = 19 V Load : BATT = 20 - 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 s
8
10 t (s)
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MB3875/MB3877
* MB3877 Conversion efficiency vs.charge current Conversion efficiency vs. charge voltage
100
Conversion efficiency (%)
96 94 92 90 88 86 84 82 80 10 m 100 m 1 10 Vin = 19 V
Conversion efficiency (%)
98
BATT charge voltage=12.6V fOSC=288.78kHz efficiency (%)=(VBATT x IBATT)/(Vin x Iin) x 100
100 98 96 94 92 90 88 86 84 82 80 0 2 4 6 8 10 12 14 16 18 Vin = 19 V R4 = 82 k
BATT= Electronic load
(Prouct of KIKUSUI PLZ-150W)
BATT charge current IBATT(A)
BATT charge voltage VBATT(V)
BATT voltage vs. BATT charge current
20 18
Vin=19v BATT:Electronic load
(Product of KIKUSUI PLZ-150W)
BATT voltage VBATT(V)
16 14 12 10 8 6 4 2 0 0 1 Dead Battery MODE
DCC MODE
DCC : Dynamically-Controlled Charging 2 3 4 5
BATT charge current IBATT(A)
Note: KIKUSUI : KIKUSUI Electronics Corp.
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MB3875/MB3877
(Continued)
Soft start operating waveforms
Vin = 19 V Load : BATT = 50 - INE = 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 s
8
10 t (s)
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MB3875/MB3877
s USAGE PRECAUTIONS
1. Never use settings exceeding maximum rated conditions.
:These dimensions do not include resin protrusion.
Exceeding maximum rated conditions may cause permanent damage to the LSI. Also, it is recommended that recommended operating conditions be observed in normal use. Exceeding recommended operating conditions may adversely affect LSI reliability.
2. Use this device within recommended operating conditions.
Recommended operating conditions are values within which normal LSI operation is warranted. Standard electrical characteristics are warranted within the range of recommended operating conditions and within the listed conditions for each parameter.
3. Printed circuit board ground lines should be set up with consideration for common impedance. 4. Take appropriate static electricity measures.
* * * * Containers for semiconductor materials should have anti-static protection or be made of conductive material. After mounting, printed circuit boards should be stored and shipped in conductive bags or containers. Work platforms, tools, and instruments should be properly grounded. Working personnel should be grounded with resistance of 250 k to 1 M between body and ground.
s ORDERING INFORMATION
Part number MB3875PFV MB3877PFV Package 24-pin plastic SSOP (FPT-24P-M03) Remarks
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MB3875/MB3877
s PACKAGE DIMENSION
24-pin plastic SSOP (FPT-24P-M03)
* 7.750.10(.305.004) * 7.750.10(.305.004)
1.25 +0.20 -0.10 1.25 -0.10 +.008 -.004 .049 +.008 .049 -.004
+0.20
(Mounting height) (Mounting height)
0.10(.004) 0.10(.004)
INDEX INDEX
* 5.600.10 * 5.600.10
(.220.004) (.220.004)
7.600.20 7.600.20 (.299.008) (.299.008)
6.60(.260) 6.60(.260) NOM NOM
0.650.12(.0256.0047) 0.650.12(.0256.0047)
+0.10 0.22 -0.05 0.22 -0.05 +.004 +.004 .009 -.002 .009 -.002
+0.10
"A" "A"
0.15 -0.02 -0.02 +.002 .006 +.002 -.001 -.001
+0.05 +0.05
Details of "A" part Details of "A" part 0.100.10(.004.004) 0.100.10(.004.004) (STAND OFF) (STAND OFF)
7.15(.281)REF 7.15(.281)REF
0 10 0 10
0.500.20 0.500.20 (.020.008) (.020.008)
CC
1994 FUJITSU LIMITED F24018S-2C-2 1994 FUJITSU LIMITED F24018S-2C-2
Dimensions in: mm (inches)
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MB3875/MB3877
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
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.
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 MIKROELEKTRONIK GmbH Am Siebenstein 6-10 D-63303 Dreieich-Buchschlag Germany Tel: (06103) 690-0 Fax: (06103) 690-122
http://www.fujitsu-ede.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/
F9908 (c) FUJITSU LIMITED Printed in Japan
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