ROHM BD8303MUV Technical data

Large Current External FET Controller Type Switching Regulators

Step-up/down, High-efficiency
Switching Regulators (Controller type)

BD8303MUV

No.09028EAT02

● General Description
ROHM’s highly-efficient step-up/down switching regulator BD8303MUV generates step-up/down output including 3.3 V / 5 V
from 1 cell of lithium battery, 4 batteries, or 2 cells of Li batteries with just one inductor.
This IC adopts an original step-up/down drive system and creates a higher efficient power supply than conventional
Sepic-system or H-bridge system switching regulators.

● Features

1)Highly-efficient step-up/down DC/DC converter to be constructed just with one inductor.

2) Supports a wide range of power supply voltage range (input voltage: 2.7 V - 14.0 V)

3) Supports high-current application with external Nch FET.

4) Incorporates soft-start function.

5) Incorporates timer latch system short protecting function.

6) High heat radiation surface mounted package QFN16 pin, 3 mm × 3 mm

● Application
General portable equipment like DVC, single-lens reflex cameras, portable DVDs, or mobile PCs

● Absolute Maximum Ratings

Parameter Symbol Rating Unit

VCC 15 V
VREG 7 V
Between BOOT

Maximum applied power voltage

Power dissipation Pd 620 mW
Operating temperature range Topr
Storage temperature range Tstg －55 to +150 °C

Junction temperature Tjmax +150 °C

When installed on a 70.0 mm × 70.0 mm × 1.6 mm glass epoxy board. The rating is reduced by 4.96 mW/°C at Ta = 25°C or more.

● Operating Conditions (Ta = 25°C)

Parameter Symbol
Power supply voltage VCC 2.7 － 14 V

Output voltage VOUT 1.8 － 12 V
Oscillation frequency fosc 0.2 0.6 1.0 MHz

* These specifications are subject to change without advance notice for modifications and other reasons.

1, 2 and SW 1, 2
Between BOOT
1, 2 and GND
SW1, 2 15 V

Standard value
MIN TYP MAX

7 V
20 V

－25 to +85

°C

Unit

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2009 ROHM Co., Ltd. All rights reserved.

2009.03 - Rev.A

BD8303MUV

● Electrical Characteristics

(Unless otherwise specified, Ta = 25 °C, VCC = 7.4 V)

Technical Note

Parameter Symbol

Minimum Typical Maximum

Target Value

Unit Conditions

[Low voltage input malfunction preventing circuit]
Detection threshold voltage VUV - 2.4 2.6 V VREG monitor
Hysteresis range ΔVUVhy 50 100 200 mV
[Oscillator]
Oscillation frequency fosc 480 600 720 kHz RT=51kΩ
[Regulator]
Output voltage VREG 4.7 5.1 5.5 V
[Error AMP]
INV threshold voltage VINV 0.9875 1.00 1.0125 V
Input bias current IINV -50 0 50 nA Vcc=12.0V , IINV=6.0V
Soft-start time Tss 2.4 4.0 5.6 msec RT=51kΩ
Output source current IEO 10 20 30 μA VINV=0.8V , VFB =1.5V
Output sink current IEI 0.6 1.3 3 mA VINV=1.2V , VFB =1.5V
[PWM comparator]
SW1 Max Duty Dmax1 85 90 95 % HG1 ON
SW2 Max Duty Dmax2 85 90 95 % LG2 ON
SW2 Min Duty Dmin2 5 10 15 % LG2 OFF
[Output]
HG1, 2 High side ON resistance RONHp - 4 8 Ω
HG1, 2 Low side ON resistance RONHn - 4 8 Ω
LG1, 2 High side ON resistance RONLp - 4 8 Ω
LG1, 2 Low side ON resistance RONLn - 4 8 Ω
HG1-LG1 dead time Tdead1 50 100 200 nsec
HG2-LG2 dead time Tdead2 50 100 200 nsec
[STB]
STB pin
control voltage

STB pin pull-down resistance

Operation V
No-operation VSTBL -0.3 - 0.3 V

STBH 2.5 - VCC V

STB 250 400 700 kΩ

R
[Circuit current]
Standby
current
Circuit current at operation
VCC
Circuit current at operation
BOOT1,2

VCC pin ISTB - - 1 μA

Icc1 - 650 1000 μA V
Icc2 - 120 240 μA V

INV=1.2V
INV=1.2V

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BD8303MUV

Technical Note

● Reference Data

1.050

1.050

1.025

1.000

0.975

VREF VOLTAGE [V]

0.950
0 5 10 15

VCC VOLTAGE [V]

1.025

1.000

0.975

VREF VOLTAGE [V]

0.950

-40 0 40 80 120

AMBIENT TEMPERATURE[℃]

6.0

5.0

4.0

3.0

2.0

VREG VOLTAGE [V]

1.0

0.0
0 5 10 15

VCC VOLTAGE [V]

Fig.1 Standard voltage -

Power supply property

Fig.2 Standard voltage -

Temperature property

Fig.3 VREG voltage -

Power supply property

5.300

5.200

5.100

5.000

4.900

VREF VOLTAGE [V]

4.800

4.700

-40 0 40 80 120

AMBIENT TEMPERATURE[℃]

1000

900
800
700
600
500
400
300

VCC CURRENT [uA]

200
100

0

0 5 10 15

Fig.4 VREG voltage –
Temperature property

VCC VOLTAGE [V]

Fig.7 ICC - Power supply

property

800

700

600

500

VREF VOLTAGE [V]

400

0 5 10 15

VCC VOLTAGE [V]

Fig.5 Oscillation frequency –

Power supply property

800

750

700

650

600

VCC CURRENT [uA]

550

500

-40 0 40 80 120

VCC VOLTAGE [V]

Fig.8 ICC - Temperature

property

700
680
660
640
620
600
580
560

VREF VOLTAGE [V]

540
520
500

-40 0 40 80 120

AMBIENT TEMPERATURE[℃]

Fig.6 Oscillation frequency -

Temperature property

160
140
120
100

80
60
40

BOOT PIN CURRENT [uA]

20

0

0123456

BOOT PIN VOLTAGE [V]

Fig.9 IBOOT - Power supply

property

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BD8303MUV

5.050

5.050

5.025

5.025

5.000

5.000

4.975

VOUT VOLTAGE [V]

4.975

VOUT VOLTAGE [V]

4.950
0 5 10 15

VCC VOLTAGE [V]

Fig.10 Line regulation Fig.11 Load regulation

4.950
0 500 1000 1500

LOAD CURRENT [mA]

STB(5.0V/div)

VOUT(2.0V/div)

Input current (200mA/div)

Fig.13 Starting waveform

(Example of Application Circuit [2])

L=10uH, Cout = 47 uH, fosc = 750

kHz, unloaded

Fig.14 Oscillation waveform

VCC = 5.0 V, Vout = 5.0 V

I LOAD = 1000 mA

100

90
80
70
60
50
40
30

EFFICIENCY [%]

20
10

0

0 1000 2000 3000

Example of Application Circuit [1]

LOAD CURRENT [mA]

Fig.16

Efficiency data (VOUT = 3.3 V)

100

90
80
70
60
50
40
30

EFFICIENCY [%]

20
10

0

0 500 1000 1500

LOAD CURRENT [mA]

Efficiency data (VOUT = 5.0 V)

Example of Application Circuit [2]

● Package Heat Reduction Curve

700

600

500

400

300

200

100

POWER DISSIPATION [mW]

0

0 25 50 75 100 125 150

AMBIENT TEMPERATURE[℃]

Fig.19 heat reduction curve (IC alone)

When used at Ta = 25°C or more, it is reduced by 4.96 mW/°C.

Fig.17

SW1 oscillation
waveform (2.0V/div)

SW2 oscillation
waveform (2.0V/div)

500usec/div

Technical Note

100

90
80
70
60
50
40
30

EFFICIENCY [%]

20
10

0

0 500 1000 1500

LOAD CURRENT [mA]

Fig.12 MAX Duty / MIN Duty

temperature property

VOUT(100mV/div)

ILOAD(500mA/div)

500usec/div

Fig.15 Load variation waveform

(Example of Application Circuit [2])

VCC = 7.4 V, Vout = 5.0 V,

I LOAD = 200 mA1000 mA :40 mA/usec

100

90
80
70
60
50
40
30

EFFICIENCY [%]

20
10

0

0 500 1000 1500 2000

LOAD CURRENT [mA]

Fig.18

Efficiency data (VOUT = 8.4 V)

Example of Application Circuit [3]

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BD8303MUV

● Description of Pins

RT

INV

FB

GND

● Block Diagram

VCC

VREG

BOOT1

STB

HG2

SW2

BOOT2

Fig. 20 Pin layout

RT

INV

FB

GND

HG1

OSC

SOFT

START

OSC x 2400 count

VREF

1.0V

SW1

LG1

PGND

LG2

VCC

UVLO

VREF

ERROR AMP

-

­+

FB=H

SCP

OSC x 8200 count

ON/OFF

LOGIC

STB

ON/OFF

Pin No. Pin Name Function

1 RT Oscillation frequency set terminal
2 INV Error AMP input terminal
3 FB Error AMP output terminal
4 GND Ground terminal
5 STB ON/OFF terminal

6 BOOT2
7 HG2

8 SW2 Output side coil connecting terminal

9 LG2
10 PGND Driver part ground terminal
11 LG1
12 SW1 Input side coil connecting terminal
13 HG1

14 BOOT1
15 VREG 5 V internal regulator output terminal

16 VCC Power input terminal

HG1

BOOT1

VREG

PRE

TIMMING

CONTROL

TIMMING

CONTROL

PRE

DRIVER

HG2

DRIVER

VREG

VREG

SW2

VREG

PWM

CONTROL

BOOT2

Fig. 21 Block diagram

PRE

PRE

Technical Note

Output side high-side driver input

terminal

Output side high-side FET gate drive

terminal

Output side low-side FET gate drive

terminal

Input side low-side FET gate drive

terminal

Input side high-side FET gate drive

terminal

Input side high-side driver input

terminal

VBAT

SW1

LG1

DRIVER

PGND

LG2

DRIVER

VOUT

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2009.03 - Rev.A