ST STOD03B User Manual

150 mA dual DC-DC converter with LDO

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

- 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

WIRE

from

STOD03B

for powering AMOLED displays

DFN12L (3 x 3 mm)

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.

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

December 2011 Doc ID 022613 Rev 1 1/22

www.st.com

Contents STOD03B

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

6.1.1 S

6.1.2 S

6.1.3 S

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

WIRE

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

WIRE

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

WIRE

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

WIRE

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

6.3 Enable and

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

WIRE

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

2/22 Doc ID 022613 Rev 1

STOD03B Schematic

1 Schematic

Figure 1. Application schematic

VBAT

CIN

S-Wire

VINA

Swire

VINP

STOD03B

LX1

VMID

CMID

VO1

CO1

CREF

Table 2. Typical external components

VREF

AGNDPGND

LX2

VO2

CO2

AM10428v1

Comp. Manufacturer Part number Value Size Ratings

COILCRAFT

MURATA

(1)

SEMCO

ABCO ABCO

COILCRAFT

(2)

MURATA

TOKO ABCO

MURATA

TAIYO YUDEN

MURATA

TAIYO YUDEN

LPS4012-472ML

LQH3NPN4R7MJ0

CIG22B4R7MNE LPF2810T-4R7M LPF2807T-4R7M

LPS4012-472ML

LQH3NPN4R7MJ0

DFE252012C 1239AS-H-

4R7N

LPF2807T-4R7M

GRM219R61A106KE44

LMK212BJ106KD-T

GRM219R61A106KE44

LMK212BJ106KD-T

4.7µH

10µF

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

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

0805 0805

±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

±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

±10%, X5R, 10V ±10%, X5R, 10V

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

10µF

0805 0805

±10%, X5R, 10V ±10%, X5R, 10V

Doc ID 022613 Rev 1 3/22

Schematic STOD03B

Table 2. Typical external components (continued)

Comp. Manufacturer Part number Value Size Ratings

MID

REF

MURATA

TAIYO YUDEN

MURATA

TAIYO YUDEN

GRM219R61A106KE44

LMK212BJ106KD-T

GRM185R60J105KE26

JMK107BJ105KK-T

10µF

1µF

0805 0805

±10%, X5R, 10V ±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.

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

VINA

S-WIRE

VINP

UVLO

LOGIC CON TROL

OTP

S-WIRE

RING

KILLER

STEP-UP CONTROL

LX1

DMD

FAST

DISCHARGE

LDO

VMID

VO1

INVERT ING CONTROL

OSC

VINP

LX2

DMD

FAST

DISCHARGE

VREF

AGND

PGND

VREF

4/22 Doc ID 022613 Rev 1

VREF

S-wire control

VO2

AM10429v1

STOD03B Pin configuration

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

WIRE

7 Negative voltage setting pin.

EN 8

IN A

12 Power input supply voltage

iN P

9 Inverting converter output voltage

10 Inverting converter switching node

11 Analogic input supply voltage

Exposed

pad

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

Voltage reference output. 1µF bypass capacitor must be connected between this pin and AGND

Enable control pin. High 1 converter on; low or floating = converter in shutdown mode

(1)

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

Doc ID 022613 Rev 1 5/22

Maximum ratings STOD03B

3 Maximum ratings

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

INA

EN, S

O1, VMID

ESD

, V

WIRE

REF

STG

DC supply voltage -0.3 to 6 V

INP

Logic input pins -0.3 to 4.6 V

Inverting converter switching current Internally limited A

Inverting converter switching node voltage -10 to V

+0.3 V

INP

Inverting converter output voltage -10 to AGND+0.3 V

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

Step-up converter switching node voltage -0.3 to V

+0.3 V

MID

Step-up converter switching current Internally limited A

Reference voltage -0.3 to 3 V

Power dissipation Internally limited mW

Storage temperature range -65 to 150 °C

Maximum junction temperature 150 °C

Human Body Model Protection ±

2kV

Machine Body Model Protection ± 200 kV

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

Functional operation under these condition is not implied.

Table 5. Thermal data

Symbol Parameter Value Unit

thJA

thJC

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

Thermal resistance junction-ambient 33 °C/W

Thermal resistance junction-case (FR-4 PCB)

(1)

2.12 °C/W

6/22 Doc ID 022613 Rev 1

STOD03B Electrical characteristics

4 Electrical characteristics

TJ = 25 °C, V C

= 2 x10 µF, C

= -4.9 V unless otherwise specified.

Table 6. Electrical characteristics

INA

= V

= 3.7 V, I

INP

= 1 µF, L1 = L2 = 4.7 µH, VEN = 2 V, V

REF

= 30 mA, CIN = 2 x10 µF, C

O1,2

= 2 x10 µF, CO1 = 10 µF,

MID

= 4.9 V, VO1 = 4.6 V,

MID

Symbol Parameter Test conditions Min. Typ. Max. Unit

General section

INA, VINP

UVLO_H Undervoltage lockout HIGH V

UVLO_L Undervoltage lockout LOW V

I_V

Q_SH

MAX

Supply input voltage 2.3 4.8 V

rising 2.22 2.25 V

INA

falling 1.9 2.18 V

INA

Input current

Shutdown current

H Enable high threshold

L Enable low threshold 0.4

Enable input current

No load condition (sum of

and V

INA

=GND (sum of V

); TJ=-40°C to +85°C;

INP

=2.3V to 4.8V,

INA

INP

)

and

INA

TJ=-40°C to +85°C;

EN=VINA

=-40°C to +85°C;

=4.8V;

1.2

1.3 1.7 mA

1µA

Switching frequency PWM mode 1.35 1.5 1.65 MHz

Step-up maximum duty cycle No load 87 %

Inverting maximum duty cycle No load 87 %

=10 to 30mA,

O1,O2

VO1=4.6V, VO2=-4.9V

75 %

η Total system efficiency

=30 to 150mA,

REF

Voltage reference I

Voltage reference current capability

O1,O2

=4.6V, VO2=-4.9V

=10µA 1.195 1.207 1.219 V

REF

At 98.5% of no load reference voltage

100 µA

82 %

OTP Overtemperature protection 140 °C

OTP

HYST

Overtemperature protection hysteresis

Positive output section

Positive voltage total variation

Line transient

Load transient regulation

ΔV

O1LT

O1T

15 °C

INA=VINP

=-40°C to +85°C; IO1=5mA

=2.3V to 4.8V;

4.554 4.6 4.646 V

to 150mA, IO2 no load

=3.5V to 3.0V,

INA,P

=100mA; TR=TF=50µs

=3 to 30mA and IO1=30 to

3mA, TR=TF=150µs

-12 mV

±20 mV

Doc ID 022613 Rev 1 7/22

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