ST STOD03B User Manual

December 2011 Doc ID 022613 Rev 1 1/22

STOD03B

150 mA dual DC-DC converter with LDO

for powering AMOLED displays

Features

■ Step-up with LDO and inverter converters

■ Operating input voltage range from 2.3 V to

4.8 V

■ Synchronous rectification for both DC-DC

converters

■ Minimum 150 mA output current

■ LDO post regulator for 4.6 V fixed positive

output to provide line and load transient

response with minimum output voltage ripple

■ Programmable negative voltage by S

WIRE

from

- 2.4 V to -5.4 V at 100 mV steps

■ Typical efficiency: 82%

■ Pulse skipping mode in light load condition

■ 1.5 MHz PWM mode control switching

frequency

■ Enable pin for shutdown mode

■ Low quiescent current in shutdown mode

■ Soft-start with inrush current protection

■ Overtemperature protection

■ Temperature range: -40 °C to 85 °C

■ True-shutdown mode

■ Package DFN (3 x 3) 12 leads 0.6 mm height

Applications

■ Active matrix AMOLED power supply in

portable devices

■ Cellular phones

■ Camcorders and digital still cameras

■ Multimedia players

Description

The STOD03B is a dual DC-DC converter for

AMOLED display panels. It integrates a step-up

and an inverting DC-DC converter making it

particularly suitable for battery operated products,

in which the major concern is the overall system

efficiency. It works in pulse skipping mode during

low load conditions and PWM-MODE at 1.5 MHz

frequency for medium/high load conditions. The

high frequency allows the value and size of

external components to be reduced. The 4.6 V

output is provided by an LDO in cascade with the

step-up converter. This allows a noise and ripple

free positive output for the AMOLED panel to

provide stable picture quality. The Enable pin

allows the device to be turned off, therefore

reducing the current consumption to less than

1 µA. The negative output voltage can be

programmed by an MCU through a dedicated pin

which implements single-wire protocol. Soft-start

with controlled inrush current limit and thermal

shutdown are integrated functions of the device.

DFN12L (3 x 3 mm)

Table 1. Device summary

Order code Positive voltage Negative voltage Package Packaging

STOD03BTPUR 4.6V - 2.4V to - 5.4V DFN12L (3 x 3mm) 3000 parts per reel

www.st.com

Contents STOD03B

2/22 Doc ID 022613 Rev 1

Contents

1 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.1 S

WIRE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.1.1 S

WIRE

features and benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.1.2 S

WIRE

protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.1.3 S

WIRE

basic operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.2 Negative output voltage levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

6.3 Enable and

WIRE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7.1 External passive components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7.1.1 Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7.1.2 Input and output capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

7.2 Recommended PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

8.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

8.1.1 Multiple operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

8.1.2 Enable pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

8.1.3 Soft-start and inrush current limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

8.1.4 Undervoltage lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

8.1.5 Overtemperature protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

STOD03B Schematic

Doc ID 022613 Rev 1 3/22

1 Schematic

Figure 1. Application schematic

VINA

CMID

VMID

LX1

VINP

CIN

Swire

S-Wire

VBAT

VREF

CREF

LX2

AGNDPGND

CO2

VO2

CO1

VO1

STOD03B

AM10428v1

Table 2. Typical external components

Comp. Manufacturer Part number Value Size Ratings

(1)

COILCRAFT

MURATA

SEMCO

ABCO

LPS4012-472ML

LQH3NPN4R7MJ0

CIG22B4R7MNE

LPF2810T-4R7M

LPF2807T-4R7M

4.7µH

4.0 x 4.0 x 1.2

3.0 x 3.0 x 1.1

2.5 x 2.0 x 1.0

2.8 x 2.8 x 1.0

2.8 x 2.8 x 0.7

±20%, curr. 1.7A, res. 0.175Ω

±20%, curr. 1.1A, res. 0.156Ω

±20%, curr. 1.1A, res. 0.300Ω

±20%, curr. 0.85A, res. 0.33Ω

±20%, curr. 0.70A, res. 0.44Ω

(2)

COILCRAFT

MURATA

TOKO

ABCO

LPS4012-472ML

LQH3NPN4R7MJ0

DFE252012C 1239AS-H-

4R7N

LPF2807T-4R7M

4.7µH

4.0 x 4.0 x 1.2

3.0 x 3.0 x 1.1

2.5 x 2.0 x 1.2

2.8 x 2.8 x 0.7

±20%, curr. 1.7A, res. 0.175Ω

±20%, curr. 1.1A, res. 0.156Ω

±30%, curr. 1.2A, res. 0.252Ω

±20%, curr. 0.70A, res. 0.44Ω

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

10µF

0805

±10%, X5R, 10V

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

10µF

0805

±10%, X5R, 10V

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

10µF

0805

±10%, X5R, 10V

Schematic STOD03B

4/22 Doc ID 022613 Rev 1

Note: All the above components refer to the typical application performance characteristics.

Operation of the device is not limited to the choice of these external components. Inductor

values ranging from 3.3 µH to 6.8 µH can be used together with STOD03B.

Figure 2. Block schematic

Comp. Manufacturer Part number Value Size Ratings

MID

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

10µF

0805

±10%, X5R, 10V

REF

MURATA

TAIYO YUDEN

GRM185R60J105KE26

JMK107BJ105KK-T

1µF

0805

±10%, X5R, 10V

1. A 200 mA load can be provided with inductor saturation current as a minimum of 0.6 A.

2. For V

in a range between - 4.9 V to -5.4 V, a load current of 150 mA to 200 mA can be provided using inductors with a

saturation current as a minimum of 1 A. See Section 7.1.1.

Table 2. Typical external components (continued)

AM10429v1

STEP-UP

CONTROL

INVERT ING

CONTROL

DISCHARGE

FAST

DISCHARGE

FAST

VREF

LOGIC CON TROL

OTP

S-WIRE

VINP

AGND

PGND

S-WIRE

VINA

LX1

LX2

RING

KILLER

VINP

VREF

OSC

S-wire

control

DMD

VREF

UVLO

VMID

VO2

VO1

LDO

STOD03B Pin configuration

Doc ID 022613 Rev 1 5/22

2 Pin configuration

Figure 3. Pin configuration (top view)

Table 3. Pin description

Pin name Pin n° Description

1 Boost converter switching node

PGND 2 Power ground pin

MID

3 Step-up converter output voltage (4.9V)

4 4.6V fixed LDO output

AGND 5 Signal ground pin. This pin must be connected to the power ground layer

REF

Voltage reference output. 1µF bypass capacitor must be connected

between this pin and AGND

WIRE

7 Negative voltage setting pin.

EN 8

Enable control pin. High 1

converter on; low or floating = converter in shutdown mode

(1)

1. No pull-up/pull-down resistors are needed.

9 Inverting converter output voltage

10 Inverting converter switching node

IN A

11 Analogic input supply voltage

iN P

12 Power input supply voltage

Exposed

pad

Internally connected to AGND. Exposed pad must be connected to ground

layers in the PCB layout in order to guarantee proper operation of the

device

Maximum ratings STOD03B

6/22 Doc ID 022613 Rev 1

3 Maximum ratings

Note: Absolute maximum ratings are those values beyond which damage to the device may occur.

Functional operation under these condition is not implied.

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

INA

, V

INP

DC supply voltage -0.3 to 6 V

EN, S

WIRE

Logic input pins -0.3 to 4.6 V

Inverting converter switching current Internally limited A

Inverting converter switching node voltage -10 to V

INP

+0.3 V

Inverting converter output voltage -10 to AGND+0.3 V

O1,

MID

LDO and step-up converter output voltage -0.3 to 6 V

Step-up converter switching node voltage -0.3 to V

MID

+0.3 V

Step-up converter switching current Internally limited A

REF

Reference voltage -0.3 to 3 V

Power dissipation Internally limited mW

STG

Storage temperature range -65 to 150 °C

Maximum junction temperature 150 °C

ESD

Human Body Model Protection ±

2kV

Machine Body Model Protection ± 200 kV

Table 5. Thermal data

Symbol Parameter Value Unit

thJA

Thermal resistance junction-ambient 33 °C/W

thJC

Thermal resistance junction-case (FR-4 PCB)

(1)

2.12 °C/W

1. The package is mounted on a 4-layer (2S2P) JEDEC board as per JESD51-7.

STOD03B Electrical characteristics

Doc ID 022613 Rev 1 7/22

4 Electrical characteristics

= 25 °C, V

INA

= V

INP

= 3.7 V, I

O1,2

= 30 mA, C

= 2 x10 µF, C

MID

= 2 x10 µF, C

= 10 µF,

= 2 x10 µF, C

REF

= 1 µF, L1 = L2 = 4.7 µH, V

= 2 V, V

MID

= 4.9 V, V

= 4.6 V,

= -4.9 V unless otherwise specified.

Table 6. Electrical characteristics

Symbol Parameter Test conditions Min. Typ. Max. Unit

General section

INA,

INP

Supply input voltage 2.3 4.8 V

UVLO_H Undervoltage lockout HIGH V

INA

rising 2.22 2.25 V

UVLO_L Undervoltage lockout LOW V

INA

falling 1.9 2.18 V

I_V

Input current

No load condition (sum of

INA

and V

INP

)

1.3 1.7 mA

Q_SH

Shutdown current

=GND (sum of V

INA

and

INP

); T

=-40°C to +85°C;

1µA

H Enable high threshold

INA

=2.3V to 4.8V,

=-40°C to +85°C;

1.2

L Enable low threshold 0.4

Enable input current

INA

=4.8V;

=-40°C to +85°C;

1µA

Switching frequency PWM mode 1.35 1.5 1.65 MHz

MAX

Step-up maximum duty cycle No load 87 %

MAX

Inverting maximum duty cycle No load 87 %

η Total system efficiency

O1,O2

=10 to 30mA,

=4.6V, V

=-4.9V

75 %

O1,O2

=30 to 150mA,

=4.6V, V

=-4.9V

82 %

REF

Voltage reference I

REF

=10µA 1.195 1.207 1.219 V

REF

Voltage reference current

capability

At 98.5% of no load

reference voltage

100 µA

OTP Overtemperature protection 140 °C

OTP

HYST

Overtemperature protection

hysteresis

15 °C

Positive output section

Positive voltage total variation

INA

INP

=2.3V to 4.8V;

=-40°C to +85°C; I

=5mA

to 150mA, I

no load

4.554 4.6 4.646 V

ΔV

O1LT

Line transient

INA,P

=3.5V to 3.0V,

=100mA; T

=50µs

-12 mV

ΔV

O1T

Load transient regulation

=3 to 30mA and I

=30 to

3mA, T

=150µs

±20 mV

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