Digital Control・

・

・

・Non-Isolated POL DC-DC Converter

BDX Series

16

Bellnix DC-DC Converter

BDD20190530_C02

7-3 BDX12-1.0S50R0S

Dual output operation

ON/OFF2

Load1

Vin

Cref1:2.2uF(2012 size Multi-layer ceramic capacitor

)

Cref2:0.1uF(1005 size Multi-layer ceramic capacitor

)

Rsa: Address setting resistor

Rcon: Configuration ID setting resistor

Ronoff1:10Ω

Conoff1:0.1uF(1005 size Multi-layer ceramic

capacitor)

VIN

PGND

VOUT

+SENSE 1

-SENSE 1

Cin1

Cout1

Cin1:22uF(3225 size Multi-layer ceramic capacitor

)×4,

10uF(3216 size Multi-layer ceramic capacitor

)×4

Cin2:22uF(3225 size Multi-layer ceramic capacitor

)×4,

10uF(3216 size Multi-layer ceramic capacitor

)×8

Cout1:100uF(3216 size Multi-layer ceramic capacitor

)×8,

47uF(2012 size Multi-layer ceramic capacitor

)×8

Cout2:100uF(3216 size Multi-layer ceramic capacitor

)×4,

47uF (2012 size Multi-layer ceramic capacitor

)×16,

1000uF(7343 size Conductive polymer capacitor

)×1

BDX12-1.0S100RM

series

7,16

8,9,14,15

10,11,12,13

37

38

+SENSE 2

-SENSE 2

35

36

SDA

SCL

SALRT

AVS_SDA

AVS_MDA

AVS_VDDIO

AVS_CLK

SGND

SA

CONFIG

32

33

24

31

25

26

22

23

6

34

PWM2

PWM3

PWM4

PWM5

PWM6

IMON2

IMON3

IMON4

IMON5

IMON6

REFIN

TMON1

TMON2

P-Good 1

P-Good 2

ON/OFF1

SW1

Rsa

Rcon

Ronoff1

Conoff1

17

20

5

18

3

1

40

30

28

27

19

4

2

21

41

39

29

VIN

PGND

VOUT

BDX12-1.0S50R0S

2,14

1,3,4,5,6,7,9,10,11,12,13,15

8

PWM

FAULT

REFIN

IMON

TMON

17

19

16

20

18

Cref2

Cout2

Cin2

VOUT1

Load2

VOUT2

Cref1

SW2

Ronoff2

Conoff2

SW1(VOUT1 ON/OFF control)

Open: Output ON

Short: Output OFF

SW1(VOUT2 ON/OFF control)

Open: Output ON

Short: Output OFF

Note 1: Make sure to connect the +SENSEx and -SENSEx pins to the converter.

Note 2: The SENSE line (the line from +SENSEx, -SENSEx pin to the both sides of Coutx) is related to the

feedback loop. Since the SENSE line is sensitive to noise, do not route the wiring long as much as

possible and wire it in parallel.

Note 3: When wiring between SWx and the converter is extended and connected, overshoot and

undershoot may occur on the ON/OFFx pin. In that case, please connect SWx via RC filter

(reference value: Ronoffx = 10 Ω, Conoffx = 0.1 μF).

Note 4:

The default setting is set for single operation, so when dual output operation is required, setting

writing by serial communication is necessary. Please refer to “BDX series Parallel, Dual output

operation Application Note” for details about parallel operation, such as setting writing and using

along with parallel operation.

Note 5: IMON-REFIN line (the line from IMONx and REFIN pin of BDX-1.0S100RM to IMON and REFIN pin

of BDX12-1.0S50R0S) is strongly related to the feedback loop and current monitor accuracy. Since

the IMON-REFIN line is sensitive to noise, do not route the wiring long as much as possible and

wire it in parallel.

Please refer to the layout commentary in "BDX series Evaluation Board User Manual" for handling

the IMON-REFIN line.

Note 6: Current signal reference voltage of 1.25V typ. is supplied to the REFIN line (the line from REFIN pin

of BDX12-1.0S100RM to REFIN pin of BDX12-1.0S50R0S) from BDX12-1.0S100RM, and it is

strongly related to current monitor accuracy. Since the REFIN line is sensitive to noise, insert a

capacitor between REFIN and GND of Cref1 = 2.2uF on BDX12-1.0S100RM side and Cref2 =

0.1uF on BDX12-1.0S50R0S side. Also, make sure to keep the capacitance 20uF or less between

REFIN and GND.

Note 7: At the PWM line (the line from PWMx pin of BDX12-1.0S100RM to PWM pin of BDX12-1.0S50R0S)

a square wave of 0⇔3.3V typ., 500kHz typ. is transmitted. Be careful not to bring PWM line close to

SENSE line, IMON - REFIN line, and to other noise sensitive lines.

Also, be careful that the PWM line does not exceed 5V.