<Setting of Output Voltage>

× (RFB11+RFB12) /RFB12

[Example of Calculation]

When RFB11=200k

[Typical Example]

The same method can be adopted for channel two (output 2) also.

[External Components]

Output 1 (Step-up DC/DC controller)

Output 2 (Step-down DC/DC controller)

Tr 1 :

* MOSFET

Tr 2 :

* MOSFET

XP161A1355PR

(TOREX N-Channel Power MOSFET)

SD 1 : MA2Q737

(Schottky , MATSUSHITA)

SD 2 : MA2Q737

(Schottky , MATSUSHITA)

CMS02

(Schottky, TOSHIBA)

CMS02

(Schottky, TOSHIBA)

L 1:

10

µH

(SUMIDA, CDRH5D28, FOSC = 500kHz)

L 2:

10

µH

(SUMIDA, CDRH5D28, FOSC = 500kHz)

15

µH

(SUMIDA, CDRH5D28, FOSC = 300kHz)

22

µH

(SUMIDA, CDRH5D28, FOSC = 300kHz)

22

µH

(SUMIDA, CDRH5D28, FOSC = 180kHz)

47

µH

(SUMIDA, CDRH5D28, FOSC = 180kHz)

CL1 :

16V, 47

µF

(Tantalum)

CL2 :

16V, 47

C=(CL standard value)

×(IOUT2 (mA)/500mA×VOUT2/VIN

Tr :

* NPN MOSFET

Tr :

* PNP MOSFET

2SD1628

(SANYO)

2SA1213

(SANYO)

RB 1 : 500

Ω ( Adjust in accordance with load & Tr.'s HFE.)

RB 2 : 500

Ω

( Adjust in accordance with load & Tr.'s HFE.)

Set according to the equation below.

Set according to the equation below.

RB1

RB2

CB1 :

2200pF (Ceramic)

CB1 :

2200pF (Ceramic)

Set according to the equation below.

Set according to the equation below.

CB1

≤ (2 π x RB2 x FOSC x 0.7)

CB2

≤ (2 π x RB2 x FOSC x 0.7)

Note : VGS Breakdown Voltage of this Tr. is 8V so

please be careful with the power supply voltage. For 6V

power supply voltage, XP161A1265PR which VGS

breakdown voltage is 12V is recommended.

VST1 of XP161A1355PR is 1.2V (max.) and that of

XP161A1265PR is 1.5V (max.)

XC9502 Series

2ch. Step-up / down DC/DC Controller ICs

The value of CFB1(CFB2), speed-up capacitor for phase compensation, should be fzfb= 1 / (2

× π × CFB1 × RFB11) which is

equal to 12kHz. Adjustments are required from 1kHz to 50kHz depending on the application, value of inductance (L), and value of

load capacity (CL).

Output voltage can be set by adding external split resistors. Output voltage is determined by the following equation, based on the

values of RFB11(RFB21) and RFB12(RFB22). The sum of RFB11(RFB21) and RFB12(RFB22) should normally be 1 M

Increase capacity according to the equation below

when the step-up voltage ratio is large and output

current is high.

C=(CL standard value)

×(IOUT1(mA)/300mA×VOUT1/VIN

VOUT

(V)

RFB11

(k

Ω)

RFB12

(k

Ω)

CFB1

(pF)

13

82

2.5

390

220

8.0

120

15

100

33

75

62

3.0

560

240

24

390

270

33

5.0

82

18

3.3

200

Note : VGS Breakdown Voltage of this Tr. is 12V so

please be careful with the power supply voltage.

Increase capacity according to the equation below

when the step-up voltage ratio is large and output

current is high.

VOUT

(V)

RFB11

(k

Ω)

RFB12

(k

Ω)

CFB1

(pF)

VOUT

(V)

RFB11

(k

Ω)

RFB12

(k

Ω)

CFB1

(pF)

330

270

39

1.0

1.5

1.8

2.0

30

270

430

220

220

62

33

220

330

62

2.7

360

180

12.0

160

160

2.2

8