Fujitsu MB3887 manual Reference Data

Page 26

MB3887

REFERENCE DATA

Conversion efficiency vs. Charge current

Conversion efficiency vs. Charge current

(Constant voltage mode)

(Constant current mode)

Conversion efficiency η (%)

100

Ta = +25 °C

98

VIN = 19 V

 

96

BATT charge voltage =

94

set at 12.6 V

SW = ON

92

Efficiency η (%) =

90(VBATT IBATT)

/ (VIN IIN) 100

88

86

84

82

80

10 m

100 m

1

Conversion efficiency η (%)

10

100

 

Ta = +25 °C

98

VIN = 19 V

 

96BATT charge voltage =

94set at 12.6 V SW = ON

92 Efficiency η (%) =

90(VBATT IBATT) / (VIN IIN)

88100

82

80

0

2

4

6

8

10

12

14

16

BATT charge current IBATT (A)

BATT charge voltage VBATT (V)

Conversion efficiency vs. Charge current

Conversion efficiency vs. Charge current

(Constant voltage mode)

(Constant current mode)

Conversion efficiency η (%)

100

98

96

94

92

90

88

86

84

82

80

10 m

Ta = +25 °C

VIN = 19 V

BATT charge voltage = set at 16.8 V

SW = ON Efficiency η (%) = (VBATT IBATT)

/ (VIN IIN) 100

100 m

1

10

Conversion efficiency η (%)

100

98

96

94

92

90

88

86

84

82

80

0

Ta = +25 °C

VIN = 19 V

BATT charge voltage = set at 16.8 V

SW = ON Efficiency η (%) = (VBATT IBATT)

/ (VIN IIN) 100

2 4 6 8 10 12 14 16 18 20

BATT charge current IBATT (A)

BATT charge voltage VBATT (V)

(Continued)

26

Image 26
Contents Package FeaturesDescription MB3887 PIN Assignment TOP ViewPin No Symbol Descriptions PIN DescriptionBlock Diagram Parameter Symbol Conditions Rating Unit Min Max Absolute Maximum RatingsParameter Symbol Conditions Value Unit Min Typ Recommended Operating ConditionsBol Min Typ Electrical CharacteristicsParameter Sym Pin Conditions Parameter Sym Pin Conditions Value Unit Bol Min Typ Max Parameter Sym Pin Conditions Value Unit Bol Min Typ OUT = −45 mA Output block Resistor Typical Characteristics Triangular wave oscillation frequency fOSC kHz Error amplifier gain and phase vs. Frequency Gain a Power dissipation vs. Ambient temperature Functional Description Output block OUT PowerPWM comparator block PWM Comp Control block CTLMethod of Setting the Triangular Wave Oscillation Frequency Setting the Charging VoltageMethod of Setting the Charging Current Soft-start block SoftMethod of Setting the SOFT-START Time Operation Timing Diagram AC Adaptor Voltage DetectionProcessing Without Using the Current AMP Connection when Current Amp is not usedProcessing Without Using of the Error AMP Connection when Error Amp is not usedProcessing Without Using of the CS Terminal Connection when soft-start time is not specifiedApplication Example At 4 cellParts List Parts NoReference Data Batt Vbatt mV Ta = +25 C, VIN = 19 Batt = 12 Ω Part number Package Remarks Usage PrecautionsOrdering Information Package Dimension IndexFujitsu Limited