FUJITSU SEMICONDUCTOR DATA SHEET
DS04-27704-2E
ASSP
For Power Supply Applications (Lithium ion battery charger)
DC/DC Converter IC for Parallel Charging
MB3874/MB3876
s DESCRIPTION
The MB3874 and MB3876 are parallel charging DC/DC converter ICs suitable for down-conversion, which uses pulse width modulation (PWM) for controlling the output voltage and current independently. These ICs can dynamically control the secondary battery's charge current by detecting a voltage drop in an AC adapter in order to keep its power constant (dynamically-controlled charging). The charging method enables quick charging, for example, with the AC adapter during operation of a notebook PC. The IC also enable parallel charging, or charging two batteries at the same time, dramatically reducing the charging time. With an on-chip output voltage setting resistor which allows the output voltage to be set at high precision, these ICs are best suited as internal battery chargers for notebook PCs. The MB3874 support 3-cell battery and the MB3876 support 4-cell battery.
s FEATURES
* Detecting a voltage drop in the AC adapter and dynamically controlling the charge current (Dynamically-controlled charging) * High efficiency : 93 %(In reverse-current preventive diode) * Wide range of operating supply voltages : 7 V to 25 V * Output voltage precision (Built-in output voltage setting resistor ) : 0.8 % (Ta = + 25 C) * High precision reference voltage source : 4.2 V 0.8 % (Continued)
s PACKAGE
24-pin plastic SSOP
(FPT-24P-M03)
MB3874/MB3876
(Continued) * Support for frequency setting using an external resistor (Frequency setting capacitor integrated) :100 kHz to 500 kHz * Built-in current detector amplifier with wide in-phase input voltage range : 0 V to VCC * Built-in standby current function : 0 A (Typ.) * Built-in soft start function * Capable of parallel charging (Charging the two battery packs at a time) * Internal totem-pole output stage supporting P-channel MOS FETs devices
2
MB3874/MB3876
s PIN ASSIGNMENT
(TOP VIEW)
-INC1 : 1 FB2 : 2 -INE2 : 3 +INE2 : 4 VREF : 5 CTL : 6 FB1 : 7 -INE1 : 8 +INE3 : 9 -INE3 : 10 FB3 : 11 -INC2 : 12
24 : +INC1 23 : GND 22 : CS 21 : VCC 20 : OUT 19 : VH 18 : OUTM 17 : RT 16 : -INE4 15 : FB4 14 : -INE5 13 : +INC2
(FPT-24P-M03)
3
MB3874/MB3876
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 -INC1 FB2 -INE2 +INE2 VREF CTL FB1 -INE1 +INE3 -INE3 FB3 -INC2 +INC2 -INE5 FB4 -INE4 RT OUTM VH OUT VCC CS GND +INC1 I/O I O I I O I O I I I O I I I O I -- O O O -- -- -- I Descriptions Output voltage feedback input pin. Error amplifier (Error Amp. 2) output pin. Error amplifier (Error Amp. 2) inverted input pin. Error amplifier (Error Amp. 2) non-inverted input pin. Input pin for charge current setting voltage Reference voltage output pin. Power supply control pin. Setting the CTL pin low places the IC in the standby mode. Error amplifier (Error Amp. 1) output pin. Error amplifier (Error Amp. 1) inverted input pin Input pin for dynamically-controlled charging voltage setting Error amplifier (Error Amp. 3) non-inverted input pin. Input pin for charge current setting voltage Error amplifier (Error Amp. 3) inverted input pin. Error amplifier (Error Amp. 3) output pin. Output voltage feedback input pin. Current detection amplifier (Current Amp. 2) input pin . Error amplifier (Error Amp. 5) inverted input pin. Error amplifier (Error Amp. 4, 5) output pin. Error amplifier (Error Amp. 4) inverted input pin. Triangular-wave oscillation frequency setting resistor connection pin. Output pin for dynamically controlled charging identification signal "H" level: Constant-voltage or constant-current charging mode "L" level: Dynamically controlled charging mode Power supply pin for FET drive circuit (VH = Vcc - 5 V). High-side FET gate drive pin. Power supply pin for reference power supply and control circuit. Soft-start capacitor connection pin. Ground pin. Current detection amplifier (Current Amp. 1) input pin .
4
MB3874/MB3876
s BLOCK DIAGRAM
-INE1 8
VCC VREF - 208 k + 42 k
- 2.5 V
OUTM 18
FB1 -INE2 +INC1 -INC1 +INE2 FB2
7 3 24 1 4 2
VREF + 100 k x 25 - - +
VCC
+ + + + - Drive
-INE3 +INC2 -INC2 +INE3 FB3
10 13 12 9 11
VREF + 100 k - x 25 - +
VCC
Bias voltage block
R1
-INE4 16
VREF
- + +
R2 50 k
-INE5
R1
14
VREF
- + +
R2 50 k
(VCC UVLO) 215 k + - 35 k
VREF (4.2 V)
0.91 V (0.77 V) VREF ULVO
FB4
15
VREF 1 A 2.5 V 1.5 V (45 pF) bias
CS
22
RT
17
VREF
5
: MB3874 100 k
MB3876 150 k
+
21
VCC
20
OUT
19
(VCC - 5 V)
VH
VCC
CTL
6
GND
23
5
MB3874/MB3876
s ABSOLUTE MAXIMUM RATINGS
Parameter Power supply voltage Output terminal current Peak output current OUTM terminal output voltage Power dissipation Storage temperature Symbol VCC IOUT IOUT VOUTM PD Tstg Ta +25C -- Conditions -- -- Duty 5% (t =1 / fOSC x Duty) -- Rating Min. -- -- -- -- -- -55 Max. 28 60 500 17 740* +125 Unit V mA mA V 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 OUTM pin output voltage OUTM pin output current Oscillator frequency Timing resistor Soft-start capacitor VH pin capacitor Reference voltage output capacitor Operating ambient temperature Symbol VCC IREF IVH V-INC VINE V+INC VCTL IOUT IOUT VOUTM IOUTM fOSC RT CS CVH CREF Ta OUT pin Duty 5% (t =1 / fOSC x Duty) -- -- -- -- -- -- -- -- -INC1, -INC2 -INE1 to -INE5, +INE2 +INC1, +INC2 -- Conditions -- -- -- Value Min. 7 -1 0 0 0 0 0 -45 -450 -- -- 100 33 -- -- -- -30 Typ. -- -- -- -- -- -- -- -- -- 3 -- 290 47 2200 0.1 0.1 +25 Max. 25 0 30 17 VCC - 1.8 VCC 25 45 450 15 1 500 130 100000 1.0 1.0 +85 Unit V mA mA V V V V mA mA V mA kHz k pF F F C
WARNING: The recommended operating conditions are required in order to ensure the normal operation of the semiconductor device. All of the device's electrical characteristics are warranted when the device is operated within these ranges. Always use semiconductor devices within their recommended operating condition ranges. Operation outside these ranges may adversely affect reliability and could result in device failure. No warranty is made with respect to uses, operating conditions, or combinations not represented on the data sheet. Users considering application outside the listed conditions are advised to contact their FUJITSU representatives beforehand. 6
MB3874/MB3876
s ELECTRICAL CHARACTERISTICS
(MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. Ta = +25C Ta = -30C to +85C VCC = 7 V to 25 V VREF = 0 mA to -1 mA 4.167 4.158 -- -- 4.200 4.200 3 1 4.233 4.242 10 10 V V mV mV
Parameter Output voltage Input stability Load stability Short-circuit output current
Symbol Pin No.
Reference voltage block (Ref)
VREF Line Load
5 5 5
IOS
5
VREF = 1 V
-25
-15
-5
mA
VTLH Threshold voltage Under voltage lockout protection circuit block (UVLO) VTHL Hysteresis width VH VTLH Threshold voltage VTHL Hysteresis width Soft-start block (SOFT) VH 5 5 21 21
VCC = VCC = -- VREF = VREF= --
6.3 5.3 0.7 2.6 2.4 0.05
6.6 5.6 1.0 2.8 2.6 0.20
6.9 5.9 1.3 3.0 2.8 0.35
V V V V V V
Charge current
ICS
22
--
-1.3
-0.8
-0.5
A
Triangular waveform oscillator circuit block (OSC)
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
MB3874/MB3876
(Continued)
(MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. FB1 = 2 V, -INE1 = 2.35 V FB1 = 2 V, -INE1 = 2.83 V -INE1= 0 V DC AV = 0 dB -- -- FB1 = 2 V FB1 = 2 V FB2 = FB3 = 2 V +INE2 = +INE3 = 0 V -- DC AV = 0 dB -- -- FB2 = FB3 = 2 V FB2 = FB3 = 2 V 14.00 16.80 -100 -- -- 3.9 -- -- 150 -- -100 0 -- -- 3.9 -- -- 150 14.20 17.10 -30 100* 2.0* 4.1 20 -2.0 300 1* -30 -- 100* 2.0* 4.1 20 -2.0 300 14.40 17.40 -- -- -- -- 200 -0.6 -- -- -- VCC-1.8 -- -- -- 200 -0.6 -- V V nA dB MHz V mV mA A mV nA V dB MHz V mV mA A
MB3874 MB3876
Parameter
Symbol Pin No
Threshold voltage Error amplifier block (Error Amp.1) Input pin current Voltage gain Frequency bandwidth Output voltage Output source current Output sink current Input offset voltage Input pin current Error amplifier block (Error Amp.2, 3) Common mode input voltage range Voltage gain Frequency bandwidth Output voltage Output source current Output sink current *: Standard design value.
VTH
21
IIN AV BW VFBH VFBL ISOURCE ISINK VIO IINE VCM AV BW VFBH VFBL ISOURCE ISINK
8 7 7 7 7 7 7 3,4 9,10 4,9 3,4 9,10 2, 11 2, 11 2, 11 2, 11 2, 11 2, 11
(Continued)
8
MB3874/MB3876
(Continued)
(MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. FB4 = 2 V, Ta = +25 C VTH 1, 12 FB1 = 2 V, Ta = -30 C to +85 C IINEH Input current Error amplifier block (Current Amp.4, 5) IINEL 1, 12 1, 12 -INC1 = -INC2 = 12.6 V -INC1 = -INC2 = 16.8 V VCC = 0 V, -INC1 = -INC2 = 12.6 V VCC = 0 V, -INC1 = -INC2 = 16.8 V -- -- DC AV = 0 dB -- -- FB4 = 2 V FB4 = 2 V 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 -- -- 3.9 -- -- 150 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 -- V V V V
MB3874 MB3876 MB3874 MB3876
Parameter
Symbol Pin No
Threshold voltage
A MB3874 A MB3876 A MB3874 A MB3876 k MB3874 k MB3876 k dB MHz V mV mA A
Input resistor Voltage gain Frequency bandwidth Output voltage Output source current Output sink current
R1 R2 AV BW VFBH VFBL ISOURCE ISINK
1, 12 14, 16 15 15 15 15 15 15
*: Standard design value.
(Continued)
9
MB3874/MB3876
(Continued)
(MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Value Conditions Unit Remarks Min. Typ. Max. +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=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=16.83 V, -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 -- -- -- -- -130 2.25 2.25 0.50 0.50 1.25 0.125 0 22.5 22.5 3.9 -- 1.4 -- 2.7 2.4 -- OUTM = 5 V OUTM = 1 mA 0.2 -- -- 10 10 -65 2.50 2.50 0.75 0.75 2.50 0.750 -- 25 25 4.1 20 1.5 2.5 2.8 2.5 0.3 0 0.15 20 20 -- 2.75 2.75 1.00 1.00 3.75 1.375 VCC 27.5 27.5 -- 200 -- 2.6 2.9 2.6 0.4 1 0.4 A MB3874 A MB3876 A V V V V V V V V/V MB3874 V/V MB3876 V mV V V V V V A V
MB3874 MB3876 MB3874 MB3876
Parameter
Symbol Pin No.
I+INCH Input current I+INCL
13, 24
13, 24
V-INE1 Current detection amplifier block (Current Amp.1, 2)
3, 10
Current detection voltage
V-INE2
3, 10
V-INE3 V-INE4 Common mode input voltage range VCM
3, 10 3, 10 1, 12, 13, 24
Voltage gain
AV
3, 10
Output voltage
PWM comparator block (PWM Comp.)
VOUTCH VOUTCL VTL
3, 10 3, 10
2, 7, Duty cycle = 0 % 11, 15 2, 7, Duty cycle = 100 % 11, 15 18 18 18 18 18 FB1 = FB1 =
Threshold voltage VTH VTLH VTHL VH ILEAK VOL
Constant power detection block (MASK Comp.)
Threshold voltage Hysteresis width Output leak current Output voltage
(Continued)
10
MB3874/MB3876
(Continued)
(MB3874 : Ta = +25C, VCC = 16 V, VREF = 0 mA) (MB3876 : Ta = +25C, VCC = 19 V, VREF = 0 mA) Parameter
Symbol Pin No.
Conditions
OUT = 11 V, Duty 5 %
Value Min. -- Typ. -200* Max. --
Unit Remarks
Output source current
ISOURCE
20
(t = 1/fosc x Duty )
OUT = 14 V, Duty 5 % OUT = 16 V, Duty 5 %
mA MB3874
(t = 1/fosc x Duty )
--
-200*
--
mA MB3876
Output block (OUT)
Output sink current
ISINK
20
(t = 1/fosc x Duty )
OUT = 19 V, Duty 5 %
--
200*
--
mA MB3874
(t = 1/fosc x Duty ) Output ON resistor Rise time Fall time ROH ROL tr1 tf1 VON VOFF ICTLH Input current ICTLL 20 20 20 20 6 6 6 6 OUT = -45 mA OUT = 45 mA OUT = 3300 pF
(Equivalent to Si4435DY)
-- -- -- -- -- 2.0 0 -- -- VCC - 5.5 -- -- --
200* 8.0 6.5 70* 60* -- -- 100 0 VCC - 5.0 0 6.0 6.5
-- 16.0 13.0 -- -- 25.0 0.8 200 1 VCC - 4.5 10 9.0 9.5
mA MB3876 ns ns V V A A
OUT = 3300 pF
(Equivalent to Si4435DY)
Control block (CTL)
Active mode Standby mode CTL = 5 V CTL = 0 V
CTL input voltage
Bias voltage block (VH)
Output voltage
VH
19
VCC = 7 V to 25 V, VH = 0 to 30 mA CTL = 0 V CTL = 5 V
V A mA MB3874 mA MB3876
General
Standby current Power supply current
ICCS ICC
21 21
*: Standard design value
11
MB3874/MB3876
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
Ta = +25 C CTL = 5 V VREF = 0 mA
4 2 0
0
5
10
15
20
25
0
5
10
15
20
25
Power supply voltage VCC (V) Reference voltage vs. VREF load current Reference voltage VREF (V)
Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) CTL = 5 V
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 (MB3874) VCC = 19 V (MB3876) CTL = 5 V VREF = 0 mA
10 8 6 4 2 0 0 5 10 15
20
25
30
VREF load current IREF (mA) Reference voltage vs. CTL pin voltage
10 Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) VREF = 0 mA 1.0
Ambient temperature Ta (C) CTL pin current vs. CTL pin voltage
Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876)
Reference voltage VREF (V)
CTL pin current ICTL (A)
8 6 4 2
0.8 0.6 0.4 0.2
0 0 5 10 15 20 25
0.0 0 5 10 15 20 25
CTL pin voltage VCTL(V)
CTL pin voltage VCTL (V)
(Continued)
12
MB3874/MB3876
(Continued)
Triangular wave oscillator frequency fOSC(kHz) Triangular wave oscillator frequency vs. timing resistor
1M Ta = +25 C VCC = 16 V (MB3874) VCC = 19 V (MB3876) 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 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)
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 (MB3874) VCC = 19 V (MB3876) CTL = 5 V
350 340 330 320 310 300 290 280 270 260 250 -40 -20 0 20
VCC = 16 V (MB3874) VCC = 19 V (MB3876) CTL = 5 V RT = 47 k
40
60
80
100
Ambient temperature Ta (C)
Ambient temperature Ta (C)
13
MB3874/MB3876
(Continued)
Error amplifier gain and phase vs. frequency
40 Ta = +25 C AV 180 4.2 V 90 VCC = 16 V (MB3874) VCC = 19 V (MB3876)
Phase (deg)
Gain AV (dB)
20
240 k IN 1 F
-+
0 -20 -40 100 1k 10 k 100 k 1M
0 -90 -180 10 M
10 k 2.4 k
3- (10)
OUT 2 (11)
10 k
4+ (9) 2.088 V Error Amp.2 (Error Amp.3)
Frequency f (Hz) Current detection amplifier gain and phase vs. frequency
Ta = +25 C AV VCC = 16 V (MB3874) VCC = 19 V (MB3876)
40
180
Gain AV (dB)
Phase (deg)
20
90
0 -20 -40 100 1k
0 -90 -180 10 k 100 k 1M
IN 0.1 V
24 (13) 1 (12)
+ x 25 -
100 k 3 OUT (10)
Current Amp.1 (Current Amp.2)
: MB3874 12.6 V MB3876 16.8 V
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)
14
MB3874/MB3876
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 21) to generate a temperature-compensated, stable voltage ( = 4.2 V) used as the reference supply voltage for the IC's internal circuitry. : The reference voltage can be output, up to 1 mA, to an external device through the VREF terminal (pin 5). (2) Triangular wave oscillator block (OSC) The triangular wave oscillator generates a triangular waveform with a frequency setting resistor connected to the internal frequency setting capacitor via the RT terminal (pin 17). The triangular wave is input to the PWM comparator on the IC. (3) Error amplifier block (Error Amp.1) This error amplifier (Error Amp.1) detects a voltage drop in the AC adapter and outputs a PWM control signal as well as a signal to the dynamically controlled charging detection block (MASK Comp.). In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB1 terminal (pin 7) to the -INE1 terminal (pin 8) of the error amplifier, enabling stable phase compensation to the system. (4) Error amplifier block (Error Amp.2, 3) These error amplifiers (Error Amp.2, Error Amp.3) detect the output signals from the current detector amplifiers (Current Amp.1, Current Amp.2), compare them with the +INE2 terminal (pin 4) and +INE3 terminal (pin 9), and output PWM control signals to control the charge current. In addition, these amplifiers allow an arbitrary loop gain to be set by connecting a feedback resistor and capacitor from the FB2 terminal (pin 2) to -INE2 terminal (pin 3) and from the FB3 terminal (pin 11) to -INE3 terminal (pin 10) of the error amplifiers, enabling stable phase compensation to the system. (5) Error amplifier block (Error Amp.4, 5) This error amplifier (Error Amp.4, Error Amp.5) detects the output voltage from the switching rerulator and outputs the PWM control signal. The error amplifier inverted input pin is connected to the output voltage setting resistor in the IC, eliminating the need for an external resistor for setting the output voltage. The MB3874 and MB3876 are set to output voltage of 12.6 V (for a 3-cell battery) and 16.8 V (for a 4-cell battery), respectively; these ICs are suitable for use in equipment that uses a lithium-ion battery. In addition, an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB4 terminal (pin 15) to the -INE4 terminal (pin 16) to the -INE5 terminal (pin 14) of the error amplifier, enabling stable phase compensation to the system. Connecting a soft-start capacitor to the CS terminal (pin 22) prevents surge currents when the IC is turned on. Using an error amplifier for soft start detection makes the soft start time constant, independent of the output load. (6) Current detector amplifier block (Current Amp.1, 2) The current detection amplifier (Current Amp.1, Current Amp.2) detects a voltage drop which occurs between both ends of the output sense resistor (RS1) due to the flow of the charge current, using the +INC1 terminal (pin 24) and -INC1 terminal (pin 1). Then it outputs the signal amplified by 25 times to the error amplifier (Error Amp.2) at the next stage.The amplifiers also detect a voltage drop which occurs at both ends of the output sense resistor
15
MB3874/MB3876
(RS2) using the +INC2 terminal (pin 13) and -INC2 terminal (pin 12) and output the signal amplified by 25 times to the error amplifier (Error Amp. 3) at the next stage. (7) PWM comparator block (PWM Comp.) The PWM comparator circuit is a voltage-pulse width converter for controlling the output duty of the error amplifiers (Error Amp. 1 to Error Amp. 5) depending on their output voltage. The PWM comparator circuit compares the triangular wave generated by the triangular wave oscillator to the error amplifier output voltage and turns on the external output transistor during the interval in which the triangular wave voltage is lower than the error amplifier output voltage. (8) Output block (OUT) The output circuit uses a totem-pole configuration capable of driving an external P-channel MOS FET. The output "L" level sets the output amplitude to 5 V (typical) using the voltage generated by the bias voltage block (VH). This results in increasing conversion efficiency and suppressing the withstand voltage of the connected external transistor in a wide range of input voltages. (9) Control block (CTL) Setting the CTL terminal (pin 6) low places the IC in the standby mode. (The supply current is 10 A at maximum in the standby mode.) (10) Bias voltage block (VH) The bias voltage circuit outputs Vcc - 5 V (typical) as the minimum potential of the output circuit. In the standby mode, this circuit outputs the potential equal to Vcc.
2. Protection Functions
Low-Vcc malfunction preventive circuit (UVLO) The transient state or a momentary decrease in supply voltage or internal reference voltage (VREF), which occurs when the power supply is turned on, may cause malfunctions in the control IC, resulting in breakdown or degradation of the system. To prevent such malfunction, the low-Vcc malfunction preventive circuit detects a supply voltage or internal reference voltage drop and fixes the OUT terminal (pin 20) to the "H" level. The system restores voltage supply when the supply voltage or internal reference voltage reaches the threshold voltage of the low-Vcc malfunction preventive circuit.
3. Soft Start Function
Soft start block (SOFT) Connecting a capacitor to the CS terminal (pin 22) prevents surge currents when the IC is turned on. Using an error amplifier for soft start detection makes the soft start time constant, independent of the output load of the DC/DC converter.
4. Additional Functions
Dynamically controlled charging detection block (MASK Comp.) The dynamically controlled charging detection block (MASK Comp.) usually output the "H" level signal. The OUTM signal becomes low ("L" level) when the output voltage of the error amplifier (Error Amp. 1) that detects the input voltage (Vcc) becomes lower than the crest value (2.5 V) of the triangular waveform generator (OSC). The OUTM signal return high ("H" level) when the input voltage reaches 2.8 V or more. 16
MB3874/MB3876
s METHOD OF SETTING THE CHARGING CURRENT
The charge current (output control current) value can be set with the voltage at the +INE2, +INE3 terminal. If a current exceeding the set value attempts to flow, the charge voltage drops according to the set current value. Battery 1 charge current setting voltage : +INE2 +INE2 (V) = 25 x I1 (A) x RS1 () Battery 2 charge current setting voltage : +INE3 +INE3 (V) = 25 x I2 (A) x RS 2 ()
s METHOD OF SETTING THE SOFT START TIME
Upon activation, the IC starts charging the capacitor (Cs) connected to the CS terminal . The error amplifier causes soft start operation to be performed with the output voltage in proportion to the CS pin voltage regardless of the load current of the DC/DC converter. Soft start time ts (Time taken for the output voltage to reach 100 %) ts (s) = 4.2 x CS (F) :
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) :
s AC ADAPTER VOLTAGE DETECTION
When partial potential point A of the AC adapter voltage (Vcc) becomes lower than the voltage at the -INE1 pin, the IC enters the constant-power mode to reduce the charge current in order to keep AC adapter power constant. AC adapter detected voltage setting Vth Vth (V) = (208k + 42k) / 42k x - INE1 = 5.95 x - INE1 : - INE1 setting voltage range : 1.176 V to 4.2 V (equivalent to 7 V to 25 V for Vcc)
-INE1 8 VCC 208 k A
- + 42 k
17
MB3874/MB3876
s OPERATION TIMING DIAGRAM
2.8 V 2.5 V Err Amp.2, 3 FB2,3 Err Amp.4, 5 FB4 Err Amp.1 FB1
1.5 V
OUT
AC adapter dynamicallycontrolled charging
OUTM
Constant voltage control
Constant current control
AC adapter dynamicallycontrolled charging
About the OUTM signal The OUTM signal becomes low when the output voltage of the error amplifier (Error Amp. 1) that detects the AC adapter voltage (Vcc) becomes lower than the crest value (2.5 V) of the triangular waveform generator (OSC). If the sum of the current consumption by the system and that by the charger exceeds the current capacity of the AC adapter, the IC detects a voltage drop in the AC adapter output and switches to the dynamically-controlled charging mode from C.V.C.C (constant-voltage/constant-current charging control) mode. In the dynamically-controlled charging mode, the OUTM pin outputs the L level signal to distinguish between the case in which the charge current has become small as the system current consumption has increased and the case in which it has become small as battery charging has been finished. L: Dynamically-controlled charging H: C.V.C.C (constant-voltage/constant-current charging control) or IC standby mode
ISYS System Power Battery Charger MB3874 MB3876
VIN AC Adaptor
Mode Signal
Ichg
Battery
18
MB3874/MB3876
s NOTE ON AN EXTERNAL REVERSE-CURRENT PREVENTIVE DIODE
If there is an imbalance in charge current (I1, I2) under constant-voltage control, voltage is controled at the side with a lower battery voltage and thus the battery voltage at one side is higher than that at the other by the voltage difference between the reverse-current preventive diodes (D1, D2) and between the sense resistors (Rs1, Rs2) Pay attention to the voltage/current characteristics of the reverse-current preventive diode (D1, D2) not to let it exceed the overcharge stop voltage.
VCC 21
VIN (16 V/19 V)
to 24 pin to 1 pin
OUT 20 I1
A
B BATT1 RS1 12.6 V/16.8 V
D1 19 VH
Battery 1
to 13 pin to 12 pin
C I2
D
BATT2 RS2 12.6 V/16.8 V
D2
Battery 2
19
MB3874/MB3876
s APPLICATION EXAMPLE
R10 2
-INE1
6800 pF C8 R8 47 k
8
VCC
R11 30 k
FB1 7
3900 pF -INE2 C9 +INC1 R16 22 k R14 5.6 k R19 200 k Q2 0.1 F C13
3
2.5 V (2.8 V) VREF + 100 k x 25 - - +
A B
24 1 4
R9 -INC1 150 k
VCC
+ + + + - Drive
+INE2 FB2
2
3900 pF -INE3 10 33 k C7 +INC2 R12 C 13 R17 22 k
SW1 R15 5.6 k R18 200 k Q3
D 12 R7 -INC2 150 k 9 0.1 F +INE3 C12 FB3 11
33 k R13
VREF + 100 k - x 25 - +
VCC
Bias voltage 19 block (VCC - 5 V)
-INE4 16
1
50 k
VREF
- + +
VIN SW2
3
-INE5
C6 3900 pF R4 200 k
14
1
50 k
VREF
- + +
(VCC UVLO) 215 k + - 35 k
C5 3900 pF R3 200 k
VREF (4.2 V) VREF 1 A 2.5 V 1.5 V (45 pF) bias
0.91 V (0.77 V)
FB4
15
VREF ULVO
CS
CS 2200 pF
22
RT RT
17
VREF 47 k
5
20
+
42 k
-
VREF - 208 k +
R6 330 k
18 OUTM
VCC 21
C14 0.1 F
C1 C2 22 F 22 F
+ - + -
C10 0.1 F
OUT 20
Pin 24 Pin 1
Q1 A I1 L1 B BATT1 RS1 4
0.075
VH
27 H C3 100 F
D1
+ -
D2 C4 100 F
+ -
Battery 1
VCC
Pin 13 Pin 12
C I2 RS2 D3 D BATT2
4
0.075
Battery 2
CTL
6
GND
23
1 : MB3874 100 k MB3876 150 k 2 : MB3874 22 k MB3876 15 k 3 : MB3874 16 V MB3876 19 V 4 : MB3874 12.6 V MB3876 16.8 V
MB3874/MB3876
s PARTS LIST
COMPONET Q1 Q2, Q3 D1 D2, D3 L1 C1, C2 C3, C4 C5, C6 C7 C8 C9 C10 CS C12, C13 C14 R1, R2 R3, R4 RT R6 R7 R8 R9 R10 R11, R12 R13 R14, R15 R16, R17 R18, R19 ITEM FET FET Diode Diode Coil OS Condensor OS Condensor Ceramics 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 SPECIFICATION Si4435DY 2N7002 MBRS130LT3 RB151L-40F 27 H 22 F 100 F 3900 pF 3900 pF 6800 pF 3900 pF 0.1 F 2200 F 0.1 F 0.1 F 0.075 200 k 47 k 330 k 150 k 47 k 150 k 22 k 30 k 30 k 5.6 k 22 k 200 k 2.8 A, 80 m 25 V (10 %) 16 V (10 %) 25 V (10 %) 10 % 10 % 10 % 10 % 25 V 10 % 16 V 16 V 1.0 % 1.0 % 1.0 % 5% 1.0 % 1.0 % 1.0 % 0.5 % 0.5 % 0.5 % 0.5 % 0.5 % 5% VENDOR
VISHAY SILICONIX VISHAY SILICONIX
PARTS NO. Si4435DY 2N7002 MBRS130LT3 RB151L-40F CDRH127-27H
MOTOROLA ROHM SUMIDA
--
--
--
--
Note: VISHAY SILICONIX : VISHAY Intertechnology, Inc. MOTOROLA : Motorola Japan Ltd. ROHM : RHOM CO., LTD SUMIDA : SUMIDA ELECTRIC CO., Ltd.
21
MB3874/MB3876
s REFERENCE DATA
* MB3874 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
BATT1 charge voltage = 12.6V, fOSC = 286.37kHz, BATT2 = OPEN (%)=(VBATT1 x IBATT1)/(Vin x Iin) x 100
98 96 94 92 90 88 86 84 82 80 0 2 4 6 Vin = 16 V R10 = 22 k
BATT2= OPEN, BATT1: Electronic load,
(Product of KIKUSUI PLZ-150W)
Vin = 16 V
100 m
1
10
8
10
12
14
16
BATT1 charge current IBATT1 (A) Conversion efficiency vs. charge current (Fixed voltage mode)
100
Paralle charging, BATT1 charge voltage = 12.6V 98 fOSC = 286.37kHz 96 (%)=((VBATT1 x IBATT1)+(VBATT2 x IBATT2))/(Vin x Iin) x 100
IBATTI = IBATT2
BATT1 charge voltage VBATT1 (V) Conversion efficiency vs. charge voltage (Fixed current mode)
100
Paralle charging, 98 BATT1: Electronic load, 96 (Product of KIKUSUI PLZ-150W), IBATTI = IBATT2 94 Vin = 16 V R10 = 22 k 92
Conversion efficiency (%)
94 92 90 88 86 84 82 80 10 m
Vin = 16 V
Conversion effciency (%)
90 88 86 84 82 80 0 2 4 6 8 10 12 14 16
100 m
1
10
BATT1 charge current IBATT1 (A) BATT voltage vs. BATT charge current
18 16 14 12 10 8 6 4 2 0 0.0 0.2 0.4 DCC : Dynamically-Controlled Charging 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Dead Battery MODE DCC MODE
Vin = 16V, BATT2= OPEN, BATT1 : Electronic load, (Product of KIKUSUI PLZ-150W)
BATT1 charge voltage VBATT1 (V) BATT voltage vs. BATT charge current
18 16 14 12 10 8 6 4 2 0 0.0 0.2 0.4 DCC : Dynamically-Controlled Charging 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Dead Battery MODE DCC MODE
Paralle charging, Vin = 16V, BATT1 : Electronic load,
(Product of KIKUSUI PLZ-150W), IBATTI=IBATT2
BATT1 voltage VBATT1 (V)
BATT1 voltage VBATT1 (V)
BATT1 charge current IBATT1 (A) Note: KIKUSUI : KIKUSUI Electronics Corp. 22
BATT1 charge current IBATT1 (A)
MB3874/MB3876
(Continued)
Soft start operating waveforms
Vin = 16 V Load : BATT1 = 20 - INE1 = 0 V BATT2 = OPEN
BATT1 (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)
DC/DC converter switching waveforms
Vin = 16 V FOSC = 286.7 kHz Load : BATT1 = 1A BATT2 = OPEN
5V 1 s
23
MB3874/MB3876
* MB3876 Conversion efficiency vs.charge current (Fixed voltage mode)
100
Conversion efficiency vs. charge voltage (Fixed current mode)
100
Conversion efficiency (%)
Conversion efficiency (%)
98 96 94 92 90 88 86 84 82 80 10 m
BATT1 charge voltage =16.8V, fOSC = 282.71kHz, BATT2 = OPEN, (%)=(VBATT1 x IBATT1)/(Vin x Iin) x 100
98 96 94 92 90 88 86 84 82 80 0 2
BATT2 = OPEN, BATT1 : Electronic load, (Prouct of KIKUSUI PLZ-150W)
Vin = 19 V
Vin = 19 V R10 = 15 k
100 m
1
10
4
6
8
10
12
14
16
18
BATT1 charge current IBATT1 (A) Conversion efficiency vs.charge current (Fixed voltage mode)
100
BATT1 charge voltage VBATT1 (V) Conversion efficiency vs. charge voltage (Fixed current mode)
100
Conversion efficiency (%)
Conversion efficiency (%)
98 96 94 92 90 88 86 84 82
Parallel charging, BATT1 Charge voltage =16.8 V, fOSC = 282.71 kHz, (%)=((VBATT1 x IBATT1)+(VBATT2 x IBATT2))/(Vin x Iin) x 100,
IBATTI = IBATT2
98 96 94 92 90 88 86 84 82 80 0 2 4
Parallel charging, BATT1 : Electronic load, (Prouct of KIKUSUI PLZ-150W),
IBATTI = IBATT2
Vin = 19 V
Vin = 19 V R10 = 15 k
80 10 m
100 m
1
10
6
8
10
12
14
16
18
BATT1 charge current IBATT1 (A) BATT voltage vs. BATT charge current
20 18 16 14 12 10 8 6 4 2 0 0.0 0.2 0.4 0.6
DCC : Dynamically-Controlled Charging Dead Battery MODE DCC MODE
Vin = 19V, BATT2 = open, BATT1:Electronic load, (Product of KIKUSUI PLZ-150W)
BATT1 charge voltage VBATT1 (V) BATT voltage vs. BATT charge current
20 18 16 14 12 10 8 6 4 2 0 0.0 0.2 0.4 0.6
DCC : Dynamically-Controlled Charging Dead Battery MODE DCC MODE
Parallel charging, Vin = 19V, BATT1: Electronic load, (Product of KIKUSUI PLZ-150W), IBATTI = IBATT2
BATT1 voltage VBATT1 (V)
BATT1 voltage VBATT1 (V)
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0.8
1.0
1.2
1.4
1.6
1.8
2.0
BATT1 charge current IBATT1 (A) Note: KIKUSUI : KIKUSUI Electronics Corp. 24
BATT1 charge current IBATT1 (A)
MB3874/MB3876
(Continued)
DC/DC converter switching waveforms
Vin = 19 V FOSC = 282.6 kHz Load : BATT1 = 1 A BATT2 = OPEN
5V OUT (V) 20 15 10 5 0 5V 0 40 80 120 20 ms 160 200 t (ms) -5 0 2 4 6 8 10 t (s) 1 s
Soft start operating waveforms
Vin = 19 V Load : BATT1 = 50 - INE1 = 0 V BATT2 = OPEN
10 V BATT1 (V) 20 CTL (V) 10 20 15 10 5 0 0
25
MB3874/MB3876
s USAGE PRECAUTIONS
1. Never use settings exceeding maximum rated conditions.
Exceeding maximum rated conditions may cause permanent damage to the LSI. Also, it is recommended that recommended operating conditions be observed in normal use. Exceeding recommended operating conditions may adversely affect LSI reliability.
2. Use this device within recommended operating conditions.
Recommended operating conditions are values within which normal LSI operation is warranted. Standard electrical characteristics are warranted within the range of recommended operating conditions and within the listed conditions for each parameter.
3. Printed circuit board ground lines should be set up with consideration for common impedance. 4. Take appropriate static electricity measures.
* * * * Containers for semiconductor materials should have anti-static protection or be made of conductive material. After mounting, printed circuit boards should be stored and shipped in conductive bags or containers. Work platforms, tools, and instruments should be properly grounded. Working personnel should be grounded with resistance of 250 k to 1 M between body and ground.
5. Do not apply negative voltages.
The use of negative voltages below -0.3 V may create parasitic transistors on LSI lines, which can cause abnormal operation
s ORDERING INFORMATION
Part number MB3874PFV MB3876PFV Package 24-pin plastic SSOP (FPT-24P-M03) Remarks
26
MB3874/MB3876
s PACKAGE DIMENSION
24-pin plastic SSOP (FPT-24P-M03)
* 7.750.10(.305.004) * 7.750.10(.305.004)
* : These dimensions do not include resin protrusion.
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)
27
MB3874/MB3876
FUJITSU LIMITED
For further information please contact:
Japan FUJITSU LIMITED Corporate Global Business Support Division Electronic Devices KAWASAKI PLANT, 4-1-1, Kamikodanaka Nakahara-ku, Kawasaki-shi Kanagawa 211-8588, Japan Tel: 81(44) 754-3763 Fax: 81(44) 754-3329
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 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 (c) FUJITSU LIMITED Printed in Japan
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