ST STOD03AS User Manual

Features

■ Step-up and inverter converters

■ Operating input voltage range from 2.5 V to

4.5 V

■ Synchronous rectification for both DC-DC

converters

■ Minimum 200 mA output current

■ 4.6 V fixed positive output voltage

■ Programmable negative voltage by S

WIRE

from

-2.4 V to -5.4 V at 100 mV steps

■ Typical efficiency: 85%

■ 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

■ Fast discharge outputs of the circuits after

shutdown

■ Short-circuit protection

■ Package DFN12L (3 x 3 mm) 0.6 mm height

Applications

■ Active matrix AMOLED power supply

■ Cellular phones

■ Camcorders and digital still cameras

■ Multimedia players

STOD03AS

Dual DC-DC converter

for powering AMOLED displays

DFN12L (3 x 3 mm)

Description

The STOD03AS is a dual DC-DC converter with
short-circuit protection 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 overall system efficiency. It works in
pulse skipping mode during light 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 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 single­wire 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

STOD03ASTPUR 4.6V -2.4V to -5.4V DFN12L (3 x 3 mm) 3000 parts per reel

December 2011 Doc ID 022614 Rev 1 1/24

www.st.com

24

Contents STOD03AS

Contents

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

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

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

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

5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6.1 S

6.1.1 S

6.1.2

6.1.3

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

WIRE

features and benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

WIRE

S

S

protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

WIRE

basic operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

WIRE

6.2 Negative output voltage levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7.1 External passive components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7.1.1 Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7.1.2 Input and output capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7.2 Recommended PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

8 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1.1 Multiple operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1.2 Pulse skipping operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1.3 Discontinuous conduction mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1.4 Continuous conduction mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.1.5 Enable pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.6 Soft-start and inrush current limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.7 Undervoltage lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.8 Overtemperature protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.9 Short-circuit protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2/24 Doc ID 022614 Rev 1

STOD03AS Contents

8.1.10 Fast discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Doc ID 022614 Rev 1 3/24

Schematic STOD03AS

1 Schematic

Figure 1. Application schematic

6

"!4

#

).

6

).!

3

%.

6

7)2%

2%&

37IRE

%.

#

2%&

,



6

).0

34/$!3

0'.$ !'.$

,

8

6

-)$

#

-)$

6

/

#

/

,

8

,



!- V

Table 2. Typical external components

Comp. Manufacturer Part number Value Size Ratings

CoilCraft

Murata

(1)

L

1

SEMCO

ABCO
ABCO

CoilCraft

Murata

(2)

L

2

TOKO
ABCO

TDK

C

IN

C

MID

C

O2

C

REF

1. A 200 mA load can be provided with inductor saturation current as a minimum of 0.5 A.

2. At -5.4 V, a 200 mA load can be provided with inductor saturation current as a minimum of 1 A. See Section 7.1.1.

Murata

Taiyo Yuden

Murata

Taiyo Yuden

Murata

Taiyo Yuden

Murata

Taiyo Yuden

LPS4012-472ML

LQH3NPN4R7MJ0

CIG22B4R7MNE

LPF2810T-4R7M
LPF2807T-4R7M

LPS4012-472ML

LQH3NPN4R7MJ0

DFE252012C1239AS-H4R7N

LPF3510T-4R7M

VLF4014AT-4R7M1R1

GRM219R61A106KE44

LMK212BJ106KD-T

GRM219R61A106KE44

LMK212BJ106KD-T

GRM219R61A106KE44

LMK212BJ106KD-T

GRM185R60J105KE26

JMK107BJ105KK-T

4.7µH

4.7µH

2 x

10µF

10µF

2 x

10µF

1µF

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

3.5 x 3.5 x 1.0

3.7 x 3.5 x 1.4

0805
0805

0805
0805

0805
0805

0603
0603

±20%, I = 1.7 A, R = 0.175Ω
±20%, I = 1.1 A, R = 0.156Ω
±20%, I = 1.1 A, R = 0.300Ω
±20%, I = 0.85 A, R = 0.33Ω
±20%, I = 0.70 A, R = 0.44Ω

±20%, I = 1.7 A, R = 0.175Ω
±20%, I = 1.1 A, R = 0.156Ω
±30%, I = 1.2 A, R = 0.252Ω
±20%, I = 0.83 A, R = 0.25Ω
±20%, I = 1.1 A, R = 0.140Ω

±10%, X5R, 10V
±10%, X5R, 10V

±10%, X5R, 10V
±10%, X5R, 10V

±10%, X5R, 10V
±10%, X5R, 10V

±10%, X5R, 6.3V
±10%, X5R, 6.3V

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 the STOD03AS.

4/24 Doc ID 022614 Rev 1

STOD03AS Schematic

Figure 2. Block schematic

6

).0

,

8

6

).!

%.

3

7)2%

6

2%&

!'.$

0'.$

56,/

,/')##/.42/,

/40

37)2%

62%&

2).'

+),,%2

34%050

#/.42/,

).6%24).'

#/.42/,

/3#

6).0

$-$

6

-)$

0!

0"

.

&!3 4

$)3#(!2'%

$-$

6

0

.

3WIRE

CONTROL

62%&

&!3 4

$)3#(!2'%

,

8

/

!-V 

Doc ID 022614 Rev 1 5/24

Pin configuration STOD03AS

2 Pin configuration

Figure 3. Pin configuration (top view)

Table 3. Pin description

Pin name Pin n° Description

Lx

1

1 Switching node of the step-up converter

PGND 2 Power ground pin

V

MID

3 Step-up converter output voltage (4.6V)

NC 4 Not internally connected

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

Voltage reference output. 1µF bypass capacitor must be connected

V

REF

S

WIRE

EN 8

V

O2

Lx

2

V

IN A

V

iN P

6

between this pin and AGND

7 Negative voltage setting pin

Enable control pin. ON = V

. When pulled low it puts the device in

INA

shutdown mode

9 Inverting converter output voltage (Default - 4.9V)

10 Switching node of the inverting converter

11 Analogic input supply voltage

12 Power input supply voltage

Exposed

pad

Internally connected to AGND. Exposed pad must be connected to AGND
and PGND in the PCB layout in order to guarantee proper operation of the
device

6/24 Doc ID 022614 Rev 1

STOD03AS Maximum ratings

3 Maximum ratings

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

V

INA

EN, S

IL

L

V

V

L

IL

V

P

T

, V

X2

X2

O2

MID

X1

X1

REF

D

STG

T

J

WIRE

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

Step-up converter and LDO 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

ESD ESD protection HBM 2 kV

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

Functional operation under these conditions is not implied.

Table 5. Thermal data

Symbol Parameter Value Unit

R

thJA

R

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

Doc ID 022614 Rev 1 7/24

Electrical characteristics STOD03AS

4 Electrical characteristics

TJ = 25 °C, V
C

= 2 x 10 µF, C

O2

INA

= V

= 3.7 V, I

INP

= 1 µF, L1 = L2 = 4.7 µH, V

REF

MID,O2

= 30 mA, C

= 2 x 10 µF, C

IN

= 2 V, V

EN

= 10 µF,

MID

= 4.6 V, VO2= -4.9 V unless

MID

otherwise specified.

Table 6. Electrical characteristics

Symbol Parameter Test conditions Min. Typ. Max. Unit

General section

V

INA, VINP

UVLO_H Undervoltage lockout HIGH V

UVLO_L Undervoltage lockout LOW V

I_V

I

Q_SH

V

EN

V

EN

I

EN

f

D1

D2

η Total system efficiency

V

REF

I

REF

Supply input voltage 2.3 3.7 4.5 V

rising 2.22 2.25 V

INA

falling 1.9 2.18 V

INA

Input current No load condition 1.7 2.1 mA

I

=GND

V

Shutdown current

H Enable high threshold

L Enable low threshold 0.4

Enable input current

S

MAX

MAX

Switching frequency PWM mode 1.2 1.5 1.7 MHz

Step-up maximum duty cycle No load 87 %

Inverting maximum duty cycle No load 87 %

Voltage reference I

Voltage reference current
capability

EN

TJ=-40°C to +85°C

V

=2.5V to 4.5V,

INA

1.2

TJ=-40°C to +85°C

V

EN=VINA

=-40°C to +85°C

T

J

I

MID,O2

V

MID

I

MID,O2

V

MID

REF

At 98.5% of no load
reference voltage

=4.5V

=10 to 30mA,

=4.6V, VO2=-4.9V

=30 to 150mA,

=4.6V, VO2=-4.9V

80 %

85 %

=10µA 1.216 1.228 1.240 V

100 µA

1µA

1µA

V

Step-up converter section

Positive voltage total variation

V

INA=VINP

I

MID

=2.5V to 4.5V;

=5mA to 150mA, IO2 no

load, TJ=25°C

V

MID

Temperature accuracy

V

INA=VINP

I

O2

=3.7V; I

no load; TJ=-40°C to

MID

+85°C

=3.5V to 3.0V,

V

ΔV

MID LT

Line transient

INA,P

=100mA; TR=TF=50µs

I

MID

8/24 Doc ID 022614 Rev 1

4.55 4.6 4.65 V

=5mA;

±0.5 %

-12 mV