STOD03ATPUR [STMICROELECTRONICS]
Dual DC-DC converter for powering AMOLED displays;
| 型号： | STOD03ATPUR |
| 厂家： | 
ST |
| 描述： | Dual DC-DC converter for powering AMOLED displays |
| 文件： | 总22页 (文件大小：496K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
STOD03A
Dual DC-DC converter for powering AMOLED displays
Datasheet
-
production data
• Fast discharge outputs of the circuits after
shutdown
• Package DFN12L (3 x 3) 0.6 mm height
Applications
• Active matrix AMOLED power supply
• Cellular phones
DFN12L (3 x 3 mm)
• Camcorders and digital still cameras
• Multimedia players
Features
• Step-up and inverter converters
Description
• Operating input voltage range from 2.3 V to
The STOD03A 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
4.5 V
• Synchronous rectification for both DC-DC
converters
• 200 mA output current
• 4.6 V fixed positive output voltages
• Programmable negative voltage by SWIRE from
- 2.4 V to - 5.4 V
• Typical efficiency: 85%
• Pulse skipping mode in light load condition
• 1.5 MHz PWM mode control switching
frequency
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.
• Enable pin for shutdown mode
• Low quiescent current: < 1 µA in shutdown
mode
• Soft-start with inrush current protection
• Overtemperature protection
• Temperature range: - 40 °C to 85 °C
• True-shutdown mode
Table 1. Device summary
Order code
Positive voltage
Negative voltage
Package
Packaging
STOD03ATPUR
4.6V
-2.4V to -5.4V
DFN12L (3 x 3mm)
3000 parts per reel
June 2013
DocID17785 Rev 3
1/22
This is information on a product in full production.
www.st.com
Contents
STOD03A
Contents
1
2
3
4
5
6
Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.1
S
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
SWIRE features and benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
SWIRE protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
WIRE
6.1.1
6.1.2
6.1.3
SWIRE basic operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.2
Negative output voltage levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1
External passive components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1.1
7.1.2
Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Input and output capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.2
7.3
Recommended PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.3.1
7.3.2
7.3.3
7.3.4
7.3.5
7.3.6
Multiple operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Enable pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Soft-start and inrush current limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Undervoltage lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Overtemperature protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fast discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8
9
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2/22
DocID17785 Rev 3
STOD03A
Schematic
1
Schematic
Figure 1. Application schematic
L1
VBAT
CIN
VINP
LX1
VMID
VINA
CMID
SWIRE
S-Wire
STOD03A
PGND AGND
VO2
EN
CO2
EN
VREF
LX2
CREF
L2
Table 2. Typical external components
Component Manufacturer
Part number
Value
Size
L1
ABCO
ABCO
TDK
LPF2807T-4R7M
LPF3509T-4R7M
4.7µH
4.7µH
4.7µH
4.7µF
4.7µF
4.7µF
1µF
2.8 x 2.8 x 0.7mm
3.5 x 3.5 x 1.0mm
3.7 x 3.5 x 1.4mm
0805
(1)
L2
VLF4014AT-4R7M1R1
GRM21BR61E475KA12
GRM21BR61E475KA12
GRM21BR61E475KA12
GRM155R60J105KE19
CIN
CMID
CO2
Murata
Murata
Murata
Murata
0805
0805
CREF
0402
1. From - 5.0 V to -5.4 V, 200 mA load can be provided with inductor saturation current as a minimum of 1 A.
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 2.2 µH to 6.8 µH can be used together with the STOD03A. See
Section 7.1.1 for peak inductor current calculation.
DocID17785 Rev 3
3/22
22
Schematic
STOD03A
Figure 2. Block schematic
LX1
VINP
DMD
RING
UVLO
VINA
KILLER
VMID
P1A
P1B
N1
STEP-UP
CONTROL
FAST
DISCHARGE
LOGIC CONTROL
OTP
EN
S-WIRE
SWIRE
OSC
DMD
VINP
VO2
N2
P2
S-wire
control
VREF
VREF
INVERTING
CONTROL
VREF
AGND
PGND
FAST
DISCHARGE
LX2
4/22
DocID17785 Rev 3
STOD03A
Pin configuration
2
Pin configuration
Figure 3. Pin configuration (top view)
Table 3. Pin description
Description
Pin name
Pin number
Lx1
PGND
VMID
NC
1
2
3
4
5
Switching node of the step-up converter
Power ground pin
Step-up converter output voltage (4.6V)
Not internally connected
AGND
Signal ground pin. This pin must be connected to the power ground pin
Voltage reference output. 1µF bypass capacitor must be connected between
this pin and AGND
VREF
SWIRE
EN
6
7
8
Negative voltage setting pin. Uses SWIRE protocol, see details in
Section 6.1.2
Enable control pin. ON=VINA. When pulled low it puts the device in
shutdown mode
VO2
Lx2
9
Inverting converter output voltage (Default -4.9V).
Switching node of the inverting converter
Analogic input supply voltage
10
11
12
VIN A
ViN P
Power input supply voltage
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
Exposed pad
DocID17785 Rev 3
5/22
22
Maximum ratings
STOD03A
3
Maximum ratings
Table 4. Absolute maximum ratings
Parameter
Symbol
Value
Unit
VINA, VINP
EN, SWIRE
ILX2
DC supply voltage
Logic input pins
-0.3 to 6
-0.3 to 4.6
V
V
Inverting converter switching current
Inverting converter switching node voltage
Inverting converter output voltage
Step-up converter and output voltage
Step-up converter switching node voltage
Step-up converter switching current
Reference voltage
Internally limited
-10 to VINP+0.3
-10 to AGND+0.3
-0.3 to 6
A
LX2
V
VO2
V
VMID
LX1
V
-0.3 to VMID+0.3
Internally limited
-0.3 to 3
V
ILX1
A
VREF
PD
V
Power dissipation
Internally limited
-65 to 150
mW
°C
°C
kV
TSTG
TJ
Storage temperature range
Maximum junction temperature
ESD protection HBM
150
ESD
2
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
RthJA
RthJC
Thermal resistance junction-ambient referred to the FR-4 PCB
Thermal resistance junction-case
48.8
2.6
°C/W
°C/W
6/22
DocID17785 Rev 3
STOD03A
Electrical characteristics
4
Electrical characteristics
TJ = 25 °C, VINA = VINP = 3.7 V, IMID,O2 = 30 mA, CIN = 4.7 µF, CMID,O2 = 4.7 µF, CREF = 1
µF, L1 = 4.7 µH, L2 = 4.7 µH, VEN = VINA = VINP, VMID = 4.6 V, VO2= -4.9 V unless otherwise
specified.
Table 6. Electrical characteristics
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
General Section
V
INA, VINP Supply input voltage
2.3
1.9
4.5
V
V
V
UVLO_H
Undervoltage lockout HIGH
Undervoltage lockout LOW
V
INA rising
INA falling
2.22
2.18
2.25
UVLO_L
I_VI
V
No load condition (sum of
VINA and VINP
Input current
1.3
1.7
1
mA
µA
)
VEN=GND (sum of VINA and
VINP); TJ=-40°C to +85°C;
IQ_SH
Shutdown current
VEN
H
Enable high threshold
Enable low threshold
1.2
1.2
V
INA=2.3V to 4.5V,
V
TJ=-40°C to +85°C;
V
EN L
0.4
1
VEN=VINA=4.5V;
TJ=-40°C to +85°C;
IEN
Enable input current
Switching frequency
µA
fS
PWM mode
1.5
87
87
1.7
MHz
%
D1MAX
D2MAX
Step-up maximum duty cycle No load
Inverting maximum duty cycle No load
%
IMID,O2=10 to 30mA,
VMID=4.6V VO2=-4.9V
80
%
n
Total system efficiency
IMID,O2=30 to 150mA,
85
%
V
V
MID=4.6V, VO2=-4.9V
VREF
IREF
Voltage reference
IREF=10µA
1.208
100
1.220
1.232
4.65
Voltage reference current
capability
At 98.5% of no load
reference voltage
µA
Step-up converter section
V
INA=VINP=2.5V to 4.5V;
Positive voltage total variation IMID=5mA to 150mA, IO2 no
load, TJ=-40°C to +85°C
4.55
4.6
V
VMID
V
INA=VINP=3.7V; IMID=5mA;
Temperature accuracy
Line transient
IO2 no load;
TJ=-40°C to +85°C
±0.5
-12
%
VINA,P=3.5V to 3.0V,
IMID=100mA; TR=TF=50µs
Δ
VMID LT
mV
DocID17785 Rev 3
7/22
22
Electrical characteristics
STOD03A
Table 6. Electrical characteristics (continued)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
I
MID=3 to 30mA and IMID=30
±20
mV
to 3mA, TR=TF=30µs
Δ
VMIDT
Load transient regulation
IMID=10 to 100mA and
I
MID=100 to 10mA,
±25
±20
mV
mV
TR=TF=30µs
I
MID=5 to 100mA; VINA,P
TDMA noise line transient
regulation
VMID-PP
=2.9V to 3.4V; F=200Hz;
TR=TF=50µs; IO2 no load
IMID MAX
I-L1MAX
Max. step-up load current
VINA,P=2.9V to 4.5V
-200
0.9
mA
A
VMID 10% below nominal
value
Step-up inductor peak current
1.1
RDSONP1
1.0
0.4
2.0
1.0
W
W
R
DSONN1
Inverting converter section
31 different values set by the
Output negative voltage range SWIRE pin
-5.4
-2.4
V
V
(see Section 6.1.2)
VINA=VINP=2.5V to 4.5V;
Output negative voltage total TJ=-40°C to +85°C;
VO2
-4.97
-4.9
-4.83
variation on default value
IO2=5mA to 150mA,
MID no load
I
V
INA=VINP=3.7V; TJ=-40°C
Temperature accuracy
to +85°C; IO2=5mA, IMID no
load
±0.5
%
VINA,P=3.5V to 3.0V,
IO2=100mA, TR=TF=50µs
Δ
VO2 LT
Line transient
+12
±20
mV
mV
IO2=3 to 30mA and IO2=30 to
3mA, TR=TF=100µs
Load transient regulation
Δ
VO2T
IO2=10 to 100mA and
Load transient regulation
I
O2=100 to 10mA,
±25
±25
mV
mV
TR=TF=100µs
IO2=5 to 100mA; VINA,P
=2.9V to 3.4V; F=200Hz;
TR=TF=50µs; IMID no load
TDMA noise line transient
regulation
VO2-PP
Maximum inverting output
current
IO2
V
INA,P=2.9V to 4.5V
-200
-1.2
mA
A
VO2 below 10% of nominal
value
I-L2MAX
Inverting peak current
-0.9
RDSONP2
0.42
0.43
W
W
R
DSONN2
Thermal shutdown
OTP
Overtemperature protection
140
°C
8/22
DocID17785 Rev 3
STOD03A
Electrical characteristics
Table 6. Electrical characteristics (continued)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Overtemperature protection
hysteresis
OTPHYST
15
°C
Discharge resistor
RDIS Resistor value
TDIS Discharge time
400
8
W
No load, VMID-VO2 at 10% of
nominal value
ms
DocID17785 Rev 3
9/22
22
Typical performance characteristics
STOD03A
5
Typical performance characteristics
VO2 = - 4.9 V; TA = 25 °C; See Table 1 for external components used in the tests below.
Figure 4. Efficiency vs. input voltage
Figure 5. Efficiency vs. output current
90%
88%
86%
84%
82%
80%
78%
76%
90%
85%
80%
75%
70%
65%
60%
55%
50%
VIN=2.7V
VIN=3.2V
VIN=3.7V
VIN=4.2V
74%
72%
70%
68%
66%
Io=50mA
Io=100mA
Io=150mA
Io=200mA
0
20 40 60 80 100 120 140 160 180 200
IOUT [mA]
2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
VIN [V]
Figure 6. Quiescent current vs. VIN no load
Figure 7. Max power output vs. VIN
500
450
400
350
300
250
200
150
100
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
10.00
9.00
8.00
7.00
-40°C
6.00
25°C
5.00
4.00
3.00
2.00
1.00
0.00
85°C
max IOUT at VO2 = -4.9V
max POUT
2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
VIN [V]
VIN [V]
Figure 8. Fast discharge VIN = 3.7 V, no load Figure 9. Startup and inrush VIN = 3.7 V, no load
EN
VMID
VO2
IIN
10/22
DocID17785 Rev 3
STOD03A
Typical performance characteristics
Figure 11. Inverting CCM operation
Figure 10. Step-up CCM operation
V
= V
= V
= 3.7 V, I = 100 mA, T = 25 °C
INP O2 A
V
= V
= V
= 3.7 V, I
= 100 mA, T = 25 °C
EN
INA
EN
INA
INP
MID A
Figure 12. Line transient
Figure 13. Output voltage vs. input voltage
IMID,O2 = 200 mA, VO2 = - 4.9 V
10.00
9.00
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
-40 °C
25 °C
85 °C
VIN
VMID
VO2
1.6
1.8
2
2.2
2.4
2.6
2.8
3
VIN [V]
V
= V
= 2.9 to 3.4 V, I
= 100 mA, T = T = 50 µs
INA
INP
MID,O2 R F
DocID17785 Rev 3
11/22
22
Detailed description
STOD03A
6
Detailed description
6.1
S
WIRE
•
•
Protocol: to digitally communicate over a single cable with single-wire components
Single-wire’s 3 components:
1. An external MCU
2. Wiring and associated connectors
3. STOD13AS device with a dedicated single-wire pin.
6.1.1
S
features and benefits
WIRE
•
•
•
Fully digital signal
No handshake needed
Protection against glitches and spikes though an internal low pass filter acting on falling
edges
•
•
Uses a single wire (plus analog ground) to accomplish both communication and power
control transmission
Simplify design with an interface protocol that supplies control and signaling over a
single-wire connection to set the output voltages.
6.1.2
S
protocol
WIRE
•
Single-wire protocol uses conventional CMOS/TTL logic levels (maximum 0.6 V for
logic “zero” and a minimum 1.2 V for logic “one”) with operation specified over a supply
voltage range of 2.5 V to 4.5 V
•
Both master (MCU) and slave (STOD13AS) are configured to permit bit sequential data
to flow only in one direction at a time; master initiates and controls the device
•
•
•
Data is bit-sequential with a START bit and a STOP bit
Signal is transferred in real time
System clock is not required; each single-wire pulse is self-clocked by the oscillator
integrated in the master and is asserted valid within a frequency range of 250 kHz
(maximum).
6.1.3
S
basic operations
WIRE
•
•
The negative output voltage levels are selectable within a wide range (steps of 100 mV)
The device can be enabled / disabled via SWIRE in combination with the Enable pin.
12/22
DocID17785 Rev 3
STOD03A
Detailed description
6.2
Negative output voltage levels
Table 7. Negative output voltage levels
Pulse
VO2
Pulse
VO2
Pulse
VO2
1
2
-5.4
-5.3
-5.2
-5.1
-5.0
-4.9
-4.8
-4.7
-4.6
-4.5
11
12
13
14
15
16
17
18
19
20
-4.4
-4.3
-4.2
-4.1
-4.0
-3.9
-3.8
-3.7
-3.6
-3.5
21
22
23
24
25
26
27
28
29
30
31
-3.4
-3.3
-3.2
-3.1
-3.0
-2.9
-2.8
-2.7
-2.6
-2.5
-2.4
3
4
5
6 (1)
7
8
9
10
1. Default output voltage.
Table 8. EN and SWIRE operation table (1)
SWIRE
Enable
Action
Low
Low
Device off
Low
High
Negative output set by SWIRE
High
Low
Default negative output voltage
Default negative output voltage
High
High
1. The Enable pin must be set to AGND while using the S
function.
WIRE
DocID17785 Rev 3
13/22
22
Application information
STOD03A
7
Application information
7.1
External passive components
7.1.1
Inductor selection
The inductor is the key passive component for switching converters.
For the step-up converter an inductance between 4.7 µH and 6.8 µH is recommended.
For the inverting stage the suggested inductance ranges from 2.2 µH to 4.7 µH.
It is very important to select the right inductor according to the maximum current the inductor
can handle to avoid saturation. The step-up and the inverting peak current can be calculated
as follows:
Equation 1
VMID ×IOUT VINMIN ×(VMID − VINMIN
)
IPEAK−BOOST
=
+
η1× VINMIN
2× VMID × fs×L1
Equation 2
-
x
x
VINMIN VO 2MIN
(VINMIN VO2MIN ) I OUT
=
+
I PEAK
-
INVERTING
x
-
x x
fs L2
η
x
2 VINMIN
2 (VO 2MIN VINMIN
)
where
V
MID: step-up output voltage, fixed at 4.6 V;
O2: inverting output voltage including sign (minimum value is the absolute maximum
V
value);
IO: output current for both DC-DC converters;
VIN: input voltage for the STOD03A;
fs: switching frequency. Use the minimum value of 1.2 MHz for the worst case;
η1: efficiency of step-up converter. Typical value is 0.85;
η2: efficiency of inverting converter. Typical value is 0.75.
The negative output voltage can be set via SWIRE at - 5.4 V. Accordingly, the inductor peak
current, at the maximum load condition, increases. A proper inductor, with a saturation
current as a minimum of 1 A, is preferred.
7.1.2
Input and output capacitor selection
It is recommended to use ceramic capacitors with low ESR as input and output capacitors in
order to filter any disturbance present in the input line and to obtain stable operation for the
two switching converters. A minimum real capacitance value of 2 µF must be guaranteed for
C
MID and CO2 in all conditions. Considering tolerance, temperature variation, and DC
polarization, a 4.7 µF 10 V capacitor can be used to achieve the required 2 µF.
14/22
DocID17785 Rev 3
STOD03A
Application information
7.2
Recommended PCB layout
The STOD03A is a high frequency power switching device and therefore requires a proper
PCB layout in order to obtain the necessary stability and optimize line/load regulation and
output voltage ripple.
Analog input (VINA) and power input (VINP) must be kept separated and connected together
at the CIN pad only. The input capacitor must be as close as possible to the IC.
In order to minimize ground noise, a common ground node for power ground and a different
one for analog ground must be used. In the recommended layout, the AGND node is placed
close to CREF ground while the PGND node is centered at CIN ground. They are connected
by a separated layer routing on the bottom through vias.
The exposed pad is connected to AGND through vias.
Detailed description
Figure 14. Top layer and top silkscreen top
Figure 15. Bottom layer and silkscreen top
DocID17785 Rev 3
15/22
22
Application information
STOD03A
7.3
General description
The STOD03A is a high efficiency dual DC-DC converter which integrates a step-up and
inverting power stages suitable for supplying AMOLED panels. Thanks to the high level of
integration it needs only 6 external components to operate and it achieves very high
efficiency using a synchronous rectification technique for each of the two DC-DC
converters.
The controller uses an average current mode technique in order to obtain good stability and
precise voltage regulation in all possible conditions of input voltage, output voltage, and
output current. In addition, the peak inductor current is monitored in order to avoid saturation
of the coils.
The STOD03A implements a power saving technique in order to maintain high efficiency at
very light load and it switches to PWM operation as the load increases, in order to guarantee
the best dynamic performance and low noise operation.
The STOD03A avoids battery leakage thanks to the true-shutdown feature and it is self
protected from overtemperature. Undervoltage lockout and soft-start guarantee proper
operation during startup.
7.3.1
Multiple operation modes
Both the step-up and the inverting stage of the STOD03A operate in three different modes:
pulse skipping mode (PS), discontinuous conduction mode (DCM), and continuous
conduction mode (CCM). It switches automatically between the three modes according to
input voltage, output current, and output voltage conditions.
Pulse skipping operation:
The STOD03A works in pulse skipping mode when the load current is below some tens of
mA. The load current level at which this way of operating occurs depends on input voltage
only for the step-up converter and on input voltage and negative output voltage (VO2) for the
inverting converter.
Discontinuous conduction mode:
When the load increases above some tens of mA, the STOD03A enters DCM operation.
In order to obtain this type of operation the controller must avoid the inductor current going
negative. The discontinuous mode detector (DMD) blocks sense the voltage across the
synchronous rectifiers (P1B for the step-up and N2 for the inverting) and turn off the
switches when the voltage crosses a defined threshold which, in turn, represents a certain
current in the inductor. This current can vary according to the slope of the inductor current
which depends on input voltage, inductance value, and output voltage.
Continuous conduction mode:
At medium/high output loads, the STOD03A enters full CCM at constant switching
frequency mode for each of the two DC-DC converters.
7.3.2
Enable pin
The device operates when the EN pin is set high. If the EN pin is set low, the device stops
switching, and all the internal blocks are turned off. In this condition the current drawn from
V
INP/VINA is below 1 µA in the whole temperature range. In addition, the internal switches
16/22
DocID17785 Rev 3
STOD03A
Application information
are in an OFF state so the load is electrically disconnected from the input, this avoids
unwanted current leakage from the input to the load.
When the EN is pulled high, the P1B switch is turned on for 100 µs. In normal operation,
during this time, apart from a small drop due to parasitic resistance, VMID reaches VIN.
If, after this 100 µs, VMID stays below VIN, the P1B is turned off and stays off until a new
pulse is applied to the EN. This mechanism avoids STOD03A starting if a short-circuit is
present on VMID
.
7.3.3
Soft-start and inrush current limiting
After the EN pin is pulled high, or after a suitable voltage is applied to VINP, VINA, and EN,
the device initiates the startup phase.
As a first step, the CMID capacitor is charged and the P1B switch implements a current
limiting technique in order to keep the charge current below 400 mA. This avoids the battery
overloading during startup.
After VMID reaches VINP voltage level, the P1B switch is fully turned on and the soft-start
procedure for the step-up is started. After about 2 ms the soft-start for the inverting is
started. The positive and negative voltage is under regulation by around 6 ms after the EN
pin is asserted high.
7.3.4
Undervoltage lockout
The undervoltage lockout function avoids improper operation of STOD03A when the input
voltage is not high enough. When the input voltage is below the UVLO threshold the device
is in shutdown mode. The hysteresis of 50 mV avoids unstable operation when the input
voltage is close to the UVLO threshold.
7.3.5
7.3.6
Overtemperature protection
An internal temperature sensor continuously monitors the IC junction temperature.
If the IC temperature exceeds 140 °C, typical, the device stops operating. As soon as the
temperature falls below 125 °C, typical, normal operation is restored.
Fast discharge
When ENABLE turns from high to low level, the device goes into shutdown mode and LX1
and LX2 stop switching. Then, the discharge switch between VMID and VIN and the switch
between VO2 and GND turn on and discharge the positive output voltage and negative
output voltage. When the output voltages are discharged to 0 V, the switches turn off and
the outputs are high impedance.
DocID17785 Rev 3
17/22
22
Package mechanical data
STOD03A
8
Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.
Table 9. DFN 12L 3X3 mechanical data
mm
Dim.
Min.
Typ.
Max.
A
A1
A3
b
0.51
0
0.55
0.02
0.20
0.25
3
0.60
0.05
0.18
2.85
1.87
2.85
1.06
0.30
3.15
2.12
3.15
1.31
D
D2
E
2.02
3
E2
e
1.21
0.45
0.40
L
0.30
0.50
18/22
DocID17785 Rev 3
STOD03A
Package mechanical data
Figure 16.DFN 12L 3X3 drawing
8085116_B
DocID17785 Rev 3
19/22
22
Package mechanical data
STOD03A
Figure 17. DFN 12L 3X3 footprint (a)
8085116_B
a. All dimensions are in millimeters
20/22
DocID17785 Rev 3
STOD03A
Revision history
9
Revision history
Table 10. Document revision history
Changes
Date
Revision
08-Sep-2010
1
2
Initial release.
06-Dec-2011
Updated Section 6 on page 12.
Updated Table 4: Absolute maximum ratings on page 6, Table 5: Thermal data
on page 6, Table 7: Negative output voltage levels on page 13 and Section 8:
Package mechanical data.
19-Jun-2013
3
DocID17785 Rev 3
21/22
22
STOD03A
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
ST PRODUCTS ARE NOT AUTHORIZED FOR USE IN WEAPONS. NOR ARE ST PRODUCTS DESIGNED OR AUTHORIZED FOR USE
IN: (A) SAFETY CRITICAL APPLICATIONS SUCH AS LIFE SUPPORTING, ACTIVE IMPLANTED DEVICES OR SYSTEMS WITH
PRODUCT FUNCTIONAL SAFETY REQUIREMENTS; (B) AERONAUTIC APPLICATIONS; (C) AUTOMOTIVE APPLICATIONS OR
ENVIRONMENTS, AND/OR (D) AEROSPACE APPLICATIONS OR ENVIRONMENTS. WHERE ST PRODUCTS ARE NOT DESIGNED
FOR SUCH USE, THE PURCHASER SHALL USE PRODUCTS AT PURCHASER’S SOLE RISK, EVEN IF ST HAS BEEN INFORMED IN
WRITING OF SUCH USAGE, UNLESS A PRODUCT IS EXPRESSLY DESIGNATED BY ST AS BEING INTENDED FOR “AUTOMOTIVE,
AUTOMOTIVE SAFETY OR MEDICAL” INDUSTRY DOMAINS ACCORDING TO ST PRODUCT DESIGN SPECIFICATIONS.
PRODUCTS FORMALLY ESCC, QML OR JAN QUALIFIED ARE DEEMED SUITABLE FOR USE IN AEROSPACE BY THE
CORRESPONDING GOVERNMENTAL AGENCY.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2013 STMicroelectronics - All rights reserved
STMicroelectronics group of companies
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -
Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
22/22
DocID17785 Rev 3
相关型号：
©2020 ICPDF网 联系我们和版权申明