Fujitsu MB3878 manual Application Example, OUTC2

Page 17

17

R14

1.3 kΩ

R16 R15

200 kΩ 110 Ω

Q2

SW

 

R8

 

 

100 kΩ −INE1 8

 

 

OUTC1 10

C10 5600 pF

R9

A

+INC1 13

 

INC1 12

10 kΩ

B

R12

 

 

30 kΩ

 

+

R13

 

INE1 9

 

FB1 7

30 kΩ

 

C8

INE2 4

10000 pF

 

R10

OUTC2 2

R4

30 kΩ

+INC2 24

R11

82 kΩ

 

R5

30 kΩ

INC2 1

 

330 kΩ

 

+INE2 3

R6

 

 

 

68 kΩ

 

FB2 5

 

R7

 

 

 

22 kΩ

 

 

R18

 

 

200 kΩ

 

 

INE3 16

 

C6

R17

 

1500 pF

100 kΩ

 

R3

11

 

330 kΩ

OUTD

 

 

FB3 15

 

CS

CS 22

 

 

 

2200 pF

 

<Current Amp.1>

<Error

VREF

 

 

 

 

 

 

 

+

Amp.1>

 

 

 

 

 

 

 

25

 

 

 

 

 

IIN

 

 

 

 

 

 

VCC (O)

 

VIN

 

+

 

 

 

 

 

 

 

 

 

 

21

 

 

AC Adaptor

 

 

 

 

 

+

 

 

 

 

<PWM Comp.>

 

C5

C1

 

 

 

 

 

0.1 F

 

 

 

 

+

<OUT>

 

 

22

F

A B

 

 

 

 

OUT

 

 

 

 

 

+

 

 

 

 

 

 

 

+

 

Drive

20

Q1

 

 

 

 

 

 

 

I1

BATT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

<Current Amp.2>

<Error

VREF

VCC

 

 

L1

 

RS

 

+

Amp.2>

 

D1

12

H

 

0.033

Ω

 

 

 

 

+

+

 

 

25

 

 

19

VH

 

Battery

+

 

Bias

 

 

 

 

 

 

Voltage

(VCC 5 V)

 

 

C2

C3

 

 

 

 

<VH>

 

 

100 F

100 F

 

Output voltage (Battery voltage) is adjustable

 

 

 

 

 

 

2.5 V

 

 

 

 

 

 

 

 

 

1.5 V

 

 

 

 

 

 

<UVLO>

VCC

 

 

 

 

<Error

 

 

 

 

 

 

 

 

VREF

 

 

 

 

 

 

 

 

Amp.3>

(VCC UVLO) 215 kΩ

 

 

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+

 

 

35 kΩ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.2 V

 

 

0.91 V

 

 

 

 

 

 

 

 

(0.77 V)

 

 

 

 

<SOFT>

 

 

VREF

 

 

 

 

 

 

 

UVLO

 

 

 

 

 

VREF

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

VCC

VCC

 

 

 

 

 

bias

 

 

 

 

 

 

 

 

 

 

 

18

 

 

 

 

 

 

 

 

 

C7

 

 

 

 

 

 

 

 

CTL

F

 

 

 

 

 

 

 

0.1

 

 

<OSC>

<REF>

<CTL>

14

 

 

 

 

 

(45 pF)

 

VREF

 

 

 

 

 

 

 

17

6

5.0 V

 

23

 

 

 

 

 

RT

VREF

GND

 

 

 

 

 

 

RT

 

 

 

 

Note : SW ON : DCC MODE

 

 

47 kΩ

 

C9

 

 

 

SW OFF : Dead Battery MODE

 

 

 

 

 

 

 

 

 

 

 

0.1 F

 

 

 

Range of input voltage

VIN=13V to 21V(at Load = 3A)

APPLICATION EXAMPLE 1

MB3878

Image 17
Contents Package FeaturesDescription TOP View PIN AssignmentPIN Description Pin No Symbol DescriptionsBlock Diagram Absolute Maximum Ragings Parameter Symbol Conditions Rating Unit Min MaxRecommended Operating Conditions ParameterParameter Symbol Pin Conditions Value Unit Min Typ Electrical CharacteristicsOutd = 1 mA 100 On resistor Parameter Symbol Pin Conditions Value Unit Min Typ Max200 Amplifier block Output source Typical Characteristics Triangular wave oscillator Deg Functional Description Output block OUT PWM comparator block PWM CompControl block CTL Bias voltage block VHMethod of Setting the Charging Current Setting the Charging VoltageMethod of Setting the SOFT-START Time Method of Setting the Triangular Wave Oscillator FrequencyAC Adaptor Voltage Detection Operation Timing DiagramVcco OUT VIN Batt Processing Without USE of the CS PINOUTC2 Application ExampleParts No Batt Reference DataVCC Vishay Siliconix Ordering Information Usage PrecautionsPart number Package Remarks MB3878PFVIndex Package DimensionFujitsu Limited