ST STOD13A 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 250 mA output current

■ 4.6 V fixed positive output voltage

■ Programmable negative voltage by S

WIRE

from

-2.4 V to -6.4 V at 100 mV steps

■ Typical efficiency 85%

■ Pulse skipping mode in light load condition

■ 1.5 MHz PWM mode control switching

frequency

■ TDMA noise high immunity

■ 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 outputs discharge circuit after shutdown

■ Short-circuit protection

■ Package DFN12L (3 x 3) 0.6 mm height

Applications

■ Active matrix AMOLED power supply in

portable devices

■ Cellular phones

■ Camcorders and digital still cameras

■ Multimedia players

Table 1. Device summary

STOD13A

250 mA dual DC-DC converter

for powering AMOLED displays

DFN12L (3 x 3 mm)

Description

The STOD13A 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 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 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, thermal shutdown and short-circuit protection are integrated functions of the device.

Order code Positive voltage Negative voltage Package Packaging

STOD13ATPUR 4.6V -2.4V to -6.4V DFN12L (3 x 3mm) 3000 parts per reel

December 2011 Doc ID 022599 Rev 1 1/24

www.st.com

Contents STOD13A

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 S

6.1.3 S

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

WIRE

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

WIRE

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

WIRE

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

WIRE

6.2 Negative output voltage levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

7 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7.1 External passive components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7.1.1 Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7.1.2 Input and output capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7.2 Recommended PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

8 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.1 Multiple operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.1.2 Enable pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.1.3 Soft-start and inrush current limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.1.4 Undervoltage lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.1.5 Overtemperature protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.1.6 Short-circuit protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.1.7 Fast discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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

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STOD13A Contents

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

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Schematic STOD13A

1 Schematic

Figure 1. Application schematic

VBAT

CIN

CREF

S-Wire

VINA

Swire

VREF

VINP

STOD13A

LX1

AGNDPGND

VMID

CMID

VO2

CO2

LX2

AM10430v1

Table 2. Typical external components

Comp. Manufacturer Part number Value Size Ratings

CoilCraft

(1)

Murata

SEMCO

ABCO

CoilCraft

(2)

Murata

TOKO

MID

REF

1. A 250 mA load can be provided with inductor saturation current as a minimum of 0.9 A.

2. At -6.4 V, a 250 mA load can be provided with inductor saturation current as a minimum of 1.5 A. See Section 7.1.1.

Murata

Taiyo Yuden

Murata

Taiyo Yuden

Murata

Taiyo Yuden

Murata

Taiyo Yuden

LPS4012-472ML

LQH3NPN4R7MJ0

CIG22B4R7MNE LPF2810T-4R7M

LPS4012-472ML

LQH3NPN4R7MJ0

DFE252012C 1239AS-H-4R7N

GRM219R61A106KE44

LMK212BJ106KD-T

GRM219R61A106KE44

LMK212BJ106KD-T

GRM219R61A106KE44

LMK212BJ106KD-T

GRM185R60J105KE26

JMK107BJ105KK-T

4.7µH

4. 7µH

2 x

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

4.0 x 4.0 x 1.2

3.0 x 3.0 x 1.1

2.5 x 2.0 x 1.2

0805 0805

0603 0603

±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. 1.7A, res. 0.175Ω ±20%, curr. 1.1A, res. 0.156Ω ±30%, curr. 1.2A, res. 0.252Ω

±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 STOD13A.

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STOD13A Schematic

Figure 2. Block schematic

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Pin configuration STOD13A

2 Pin configuration

Figure 3. Pin configuration (top view)

Table 3. Pin description

Pin name Pin number Description

1 Boost converter switching node.

PGND 2 Power ground pin.

MID

FD 4

AGND 5

REF

WIRE

EN 8

IN A

12 Power input supply voltage.

IN P

3 Boost converter output voltage.

Fast discharge control pin. When pulled LOW the fast discharge after shutdown is active. When pulled HIGH the fast discharge is OFF.

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

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

7 Negative voltage setting pin.

Enable control pin. high = converter on; low = converter in shutdown mode.

9 Inverting converter output voltage.

10 Inverting converter switching node.

11 Analogic 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.

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STOD13A Maximum ratings

3 Maximum ratings

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

, V

INA

EN, S

WIRE

FD Logic input pin - 0.3 to V

ILx

MID

ILx

REF

ESD

DC supply voltage - 0.3 to 6 V

INP

Logic input pins - 0.3 to 4.6 V

INA

Inverting converter switching current Internally limited A

Inverting converter switching node voltage - 10 to V

INP

Inverting converter output voltage - 10 to AGND+0.3 V

Step-up converter output voltage -0.3 to 6 V

Step-up converter switching node voltage - 0.3 to V

MID

Step-up converter’s 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 ± 2 kV

Machine body model protection ± 200 V

+0.3 V

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

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

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Electrical characteristics STOD13A

4 Electrical characteristics

TJ = 25 °C, V C

= 2 x 10 µF, C

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

= 2 V, V

= 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

INA, VINP

UVLO_H Undervoltage lockout HIGH V

UVLO_L Undervoltage lockout LOW V

Q_SH

VFD H Fast discharge high threshold

fs Switching frequency PWM mode 1.35 1.5 1.65 MHz

REF

Supply input voltage 2.5 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

Shutdown current VEN=GND; TJ=-40°C to +85°C 1 µA

H Enable high threshold

INA

TJ=-40°C to +85°C

1.2 V

=2.5V to 4.5V,

L Enable low threshold 0.4

Enable input current

EN=VINA

TJ=-40°C to +85°C

INA

TJ=-40°C to +85°C

=4.5V;

=2.5V to 4.5V,

1.2 V

L Fast discharge low threshold 0.4

MAX

Step-up maximum duty cycle No load 87 %

Inverting maximum duty cycle No load 87 %

=10 to 30mA,

Total system efficiency

Reference voltage I

Reference current capability

MID,O2

=4.6V, VO2=-4.9V

MID

=30 to 150mA, V

MID,O2

=-4.9V

=150 to 250mA,

MID,O2

=4.6V, VO2=-4.9V

MID

=10µA 1.208 1.220 1.232 V

REF

At 98.5% of no load reference voltage

MID

=4.6V,

100 µA

78 %

1µA

Step-up converter section

Positive output voltage 4.6 V

=2.9V to 4.5V;

=5mA to 250mA, IO2 no load

=3.4V to 2.9V, I

=10µs

ΔV

MID

MID LT

Positive output voltage total variation

Line transient

INA=VINP

MID

= -40°C to +85°C

INA,P

R=TF

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=100mA;

MID

-0.8 0.8 %

-10 mV

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