Analogic AAT3112 500ma high efficiency charge pump for white led flash application Datasheet

AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
General Description
Features
The AAT3112 is a member of AnalogicTech's Total
Power Management IC™ (TPMIC™) family. It is a
dual voltage doubling charge pump that provides a
regulated output voltage. It operates with an input
voltage range of 2.7 to 5.0 volts. The device can
deliver a constant 200mA output load current and up
to 500mA of pulsed current. The 500mA peak current capability of the AAT3112 makes it ideal for
white LED flash applications. A low external parts
count (two 1µF flying capacitors and two small
capacitors at VIN and VOUT) makes the AAT3112 ideally suited for small battery-powered applications.
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The AAT3112 has a thermal management system
to protect the device in the event of a short-circuit
condition at the output pin. Built-in soft-start circuitry prevents excessive inrush current during startup. A high charge pump switching frequency
enables the use of very small external capacitors.
A low current shutdown feature disconnects the
load from VIN and reduces quiescent current to less
than 1µA. The AAT3112 is available in a 16-pin
3x3mm QFN package and is rated over the -40°C
to +85°C temperature range.
ChargePump™
Input Voltage Range:
• AAT3112-5.0: 2.7V to 5.0V
• AAT3112-4.5: 2.7V to 4.5V
Up to 500mA Peak Output Current
200mA Continuous Output Current
IQ <1µA in Shutdown
Regulated 4.5V or 5.0V Output
26µA of Quiescent Current
Small Application Circuit
Automatic Soft Start
No Inductors
Short-Circuit/Over-Temperature Protection
16-Pin 3x3mm QFN Package
Temperature Range: -40°C to +85°C
Applications
•
•
•
General-Purpose High-Current Boost Supply
White LED Backlighting
White LED Photo Flash
Typical Application
VIN
C1 = 1µF
C2 = 1µF
C1+
C2 +
C1-
VIN
C2 VOUT1
CIN
C OUT
VOUT2
AAT3112
D1
Enable Light
EN1
Enable Flash
EN2
GND
3112.2004.12.1.2
D2
D3
D4
RB
1
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Pin Descriptions
Pin #
Symbol
1
2
3
4
5
6
7
N/C
C2+
C2N/C
VIN
GND
EN2
8
9
N/C
EN1
10
11
12
GND
VIN
VOUT1
13
14
15
16
N/C
C1+
C1VOUT2
EP
Function
No connect.
Flying capacitor 2 positive terminal. Connect 1µF capacitor between C2+ and C2-.
Flying capacitor 2 negative terminal.
No connect.
Input voltage. Connect to Pin 11.
Ground connection.
Enable pin. When connected high, Charge Pump 2 is enabled. When connected low, it
disables the charge pump.
No connect.
Enable pin. When connected high, Charge Pump 1 is enabled. When connected low, it
disables the charge pump.
Ground connection.
Input voltage. Connect to Pin 5.
Output pin for regulated output voltage. Bypass this pin to ground with a low ESR 10µF
capacitor.
No connect.
Flying capacitor 1 positive terminal. Connect 1µF capacitor between C1+ and C1-.
Flying capacitor 1 negative terminal.
Regulated output voltage 2. Must be connected to VOUT1 for higher current applications.
If used separately, bypass this pin to ground with a low ESR 10µF capacitor.
Exposed paddle (bottom); connect to GND directly beneath package.
Pin Configuration
QFN33-16
(Top View)
N/C
C1+
C1VOUT2
13
14
15
16
N/C
C2+
C2N/C
1
12
2
11
3
10
4
9
VOUT1
VIN
GND
EN1
8
7
6
5
N/C
EN2
GND
VIN
2
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Absolute Maximum Ratings1
Symbol
VIN
VOUT
VEN
TJ
TLEAD
Description
Input Voltage
Charge Pump Output
EN to GND Voltage
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Value
Units
-0.3 to 6
-0.3 to 6
-0.3 to 6
-40 to 150
300
V
V
V
°C
°C
Note 1: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
Thermal Information
Symbol
PD
θJA
Description
Maximum Power Dissipation
Maximum Thermal Resistance1
Value
Units
2.0
50
W
°C/W
Note 1: Mounted on an FR4 board.
3112.2004.12.1.2
3
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Electrical Characteristics
VIN = 3.3V, VOUT = 5.0V, CIN = COUT = 10 µF, C1 = C2 = 1.0µF; TA = -40°C to 85°C, unless otherwise noted.
Typical values are TA = 25°C.
Symbol
Description
AAT3112-4.5
Input Power Supply
VIN
Operation Range
IQ
Quiescent Current
ISHDN
Shutdown Current
Conditions
Pulsed Output Current
VOUT
Output Voltage
Charge Pump Section
FCLK
Clock Frequency
ηCP
Charge Pump Efficiency
EN
VEN(L)
Enable Threshold Low
VEN(H)
Enable Threshold High
IEN
EN Input Leakage
AAT3112-5.0
Input Power Supply
VIN
Operation Range
IQ
Quiescent Current 2
ISHDN
Shutdown Current
Pulsed Output Current
IOUT
Charge Pump
FCLK
ηCP
EN
VEN(L)
VEN(H)
IEN
Typ Max Units
2.7
2
IOUT
VOUT
Min
Output Voltage
Section
Clock Frequency
Charge Pump Efficiency
Enable Threshold Low
Enable Threshold High
EN Input Leakage
2.7 ≤ VIN ≤ 4.5, IOUT = 0 mA; EN1 = EN2 = VIN
EN1 = EN2 = 0
VIN = 3.6V; VOUT = 4.0V; TPULSE = 50mS
VIN = 3.6V; VOUT =4.0V; TPULSE = 500mS
2.7 ≤ VIN ≤ 4.5, IOUT = 100mA
3.0 ≤ VIN ≤ 4.5, IOUT = 200mA
26
4.32
4.32
590
500
4.5
4.5
4.5
60
1.0
mA
4.68
4.68
750
80
VIN = 2.7V; IOUT = 100mA
2.7
2.7 ≤ VIN ≤ 5.0, IOUT = 0 mA; EN1 = EN2 = VIN
EN1 = EN2 = 0
VIN = 3.6V; VOUT = 4.5V; TPULSE = 50mS
VIN = 3.6V; VOUT =4.5V; TPULSE = 500mS
2.7 ≤ VIN ≤ 5.0, IOUT = 100mA
3.0 ≤ VIN ≤ 5.0, IOUT = 200mA
26
4.8
4.8
600
500
5.0
5.0
1.0
V
V
µA
5.0
60
1.0
V
µA
µA
mA
5.2
5.2
750
85
VIN = 2.7V; IOUT = 100mA
V
KHz
%
0.3
1.4
-1.0
V
KHz
%
0.3
1.4
-1.0
V
µA
µA
1.0
V
V
µA
Notes:
1. The AAT3112 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured
by design, characterization, and correlation with statistical process controls.
2. VOUT1 and VOUT2 are pulled high to prevent switching.
4
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
VIN vs. VIL
VIN vs. VIH
1.00
1.00
0.90
0.95
-40°C
0.85
VIH (V)
0.90
-40°C
0.85
25°C
0.80
0.80
VIL (V)
0.95
0.75
0.70
85°C
0.65
25°C
0.75
0.70
0.65
0.60
85°C
0.60
0.55
0.55
0.50
0.50
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
VSHDN Threshold vs. Supply Voltage
1.00
VSHDN Threshold (V)
0.95
0.90
VIH
0.85
0.80
0.75
0.70
VIL
0.65
0.60
0.55
0.50
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
3112.2004.12.1.2
5
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-4.5V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Supply Current vs. Supply Voltage
Output Voltage vs. Output Current
(No Load, No Switching)
30
5.0
4.8
VIN = 3.6V
Supply Current (µ
µA)
Output Voltage (V)
4.9
VIN = 3.9V
4.7
4.6
4.5
VIN = 4.2V
4.4
4.3
4.2
25
20
15
10
5
4.1
0
4.0
0
50
100
150
200
250
2.5
300
3.0
3.5
Startup Time with 100mA Load
Startup Time with 200mA Load
EN
(2V/div)
EN
(2V/div)
VOUT
(1V/div)
VOUT
(1V/div)
50µ
µs/div
50µ
µs/div
Maximum Current Pulse (50ms pulse)
vs. Input Voltage, VOUT > 4.0V
Efficiency vs. Supply Voltage
85
800
80
Efficiency (%)
Maximum Current Pulse (mA)
4.5
Supply Voltage (V)
Output Current (mA)
700
600
500
50mA
75
70
65
200mA
60
100mA
55
50
400
45
300
3
3.2
3.4
3.6
Input Voltage (V)
6
4.0
3.8
4
4.2
40
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.5
Input Voltage (V)
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-4.5V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Load Transient Response
Load Transient Response
(VIN = 3.0V)
(VIN = 4.2V)
IOUT
(200mA/div)
IOUT
(200mA/div)
VOUT
(20mV/div)
VOUT
(20mV/div)
50µs/div
50µs/div
Input and Output Ripples
Input and Output Ripples
(IOUT = 50mA @ VIN = 3.5V)
(IOUT = 100mA @ VIN = 3.5V)
VIN
AC Coupled
(20mV/div)
VIN
AC Coupled
(20mV/div)
VOUT
AC Coupled
(20mV/div)
VOUT
AC Coupled
(20mV/div)
5µs/div
5µs/div
Output Current vs. Input Voltage
Output Current vs. Input Voltage (70°C)
(500ms Pulse Time; VOUT > 4.0V)
(VOUT > 4.0V)
800
Output Current (mA)
Output Current (mA)
800
700
600
500
400
300
200
100
0
50ms
100ms
700
600
200ms 300ms
500
500ms
400
300
200
100
0
2.5
3
3.5
Input Voltage (V)
3112.2004.12.1.2
4
4.5
2.5
3.0
3.5
4.0
4.5
Input Voltage (V)
7
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-4.5V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Output Voltage vs. Input Voltage for
Pulsed High Current, IOUT = 500mA
5
50ms Pulse
Output Voltage (V)
4.5
4
3.5
500ms Pulse
3
2.5
2
1.5
1
0.5
0
3
3.2
3.4
3.6
3.8
4
4.2
Input Voltage (V)
8
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-5.0V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Output Voltage vs. Output Current
Supply Current vs. Supply Voltage
(No Load, No Switching)
30
Output Voltage (V)
5.4
5.3
5.2
VIN = 4.2V
5.1
VIN = 3.9V
5.0
4.9
VIN = 3.6V
4.8
4.7
Supply Current (µ
µA)
5.5
25
20
15
10
5
4.6
0
4.5
0
50
100
150
200
250
2.5
300
3.0
3.5
Output Current (mA)
4.5
5.0
Supply Voltage (V)
Startup Time with 100mA Load
Startup Time with 200mA Load
EN
(2V/div)
EN
(2V/div)
VOUT
(1V/div)
VOUT
(1V/div)
50µ
µs/div
50µ
µs/div
Efficiency vs. Supply Voltage
Maximum Current Pulse (50ms pulse)
vs. Input Voltage, VOUT > 4.5V
95
100mA
90
1000
Efficiency (%)
Maximum Current Pulse (mA)
4.0
900
800
700
600
85
80
75
70
200mA
65
50mA
60
55
500
50
400
300
3.0
45
40
3.2
3.4
3.6
Input Voltage (V)
3112.2004.12.1.2
3.8
4.0
4.2
2.7
3.0
3.3
3.5
3.8
4.1
4.4
4.7
4.9
Input Voltage (V)
9
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-5.0V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Load Transient Response
Load Transient Response
(VIN = 3.0V)
(VIN = 4.2V)
IOUT
(200mA/div)
IOUT
(200mA/div)
VOUT
(20mV/div)
VOUT
(20mV/div)
50µs/div
50µs/div
Input and Output Ripples
Input and Output Ripples
(IOUT = 50mA @ VIN = 3.5V)
(IOUT = 100mA @ VIN = 3.5V)
VIN
AC Coupled
(20mV/div)
VIN
AC Coupled
(20mV/div)
VOUT
AC Coupled
(20mV/div)
VOUT
AC Coupled
(20mV/div)
5µs/div
5µs/div
Output Current vs. Input Voltage
Output Current vs. Input Voltage (70°C)
(500ms Pulse Time; VOUT > 4.5V)
(VOUT > 4.5V)
1000
800
50ms
Output Current (mA)
Output Current (mA)
900
800
700
600
500
400
300
200
100
0
600
500
200ms 300ms
400
500ms
300
200
100
0
3.0
3.5
4.0
Input Voltage (V)
10
100ms
700
4.5
5.0
2.5
3.0
3.5
4.0
4.5
Input Voltage (V)
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Typical Characteristics-AAT3112-5.0V
VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted.
Output Voltage vs. Input Voltage for
Pulsed High Current, IOUT = 500mA
Output Voltage (V)
6
5
50ms Pulse
4
3
500ms Pulse
2
1
0
3.0
3.2
3.4
3.6
3.8
4.0
4.2
Input Voltage (V)
3112.2004.12.1.2
11
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Functional Block Diagram
V IN
S2
S1
C1 +
EN1
Control
Circuit
C1 S4
S3
VOUT1
EN2
Control
Circuit
GND
S1
S2
S3
S4
C2+
C2V OUT2
Functional Description
The AAT3112 is a dual charge pump intended for
high-current applications. This device boosts an
input voltage to a regulated output voltage.
Regulation is achieved by sensing the output voltage through an internal resistor divider network.
The AAT3112 requires only four external components: two 1.0µF ceramic capacitors for the charge
pump (C1 and C2), one 10µF ceramic capacitor for
CIN, and one 10µF ceramic capacitor for COUT.
12
The AAT3112 is designed to deliver 200mA of continuous current and up to 500mA of pulsed current.
Each charge pump engine has an independent
enable pin to extend battery life. The charge pump
switching frequency is approximately 750kHz,
enabling the use of small external flying capacitors.
The AAT3112 has complete output short-circuit and
thermal protection to safeguard the device under
extreme operating conditions. An internal thermal
protection circuit senses die temperature and will
shut down the device if the internal junction temperature exceeds approximately 145°C.
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Applications Information
Charge Pump Efficiency
The AAT3112 is a regulated output voltage doubling charge pump. The efficiency (η) can simply
be defined as a linear voltage regulator with an
effective output voltage that is equal to two times
the input voltage. Efficiency (η) for an ideal voltage
doubler can typically be expressed as the output
power divided by the input power:
η=
POUT
PIN
In addition, with an ideal voltage doubling charge
pump, the output current may be expressed as half
the input current. The expression to define the
ideal efficiency (η) can be rewritten as:
η=
POUT VOUT × IOUT VOUT
=
=
PIN
VIN × 2IOUT
2VIN
-orη(%) = 100
⎛ VOUT ⎞
⎝ 2VIN ⎠
For a charge pump with an output of 4.5 volts and
a nominal input of 2.8 volts, the theoretical efficiency is 80.4%. Due to internal switching losses and
IC quiescent current consumption, the actual efficiency can be measured at 79.6%. These figures
are in close agreement across a wide range of output load conditions. Efficiency will decrease as
load current drops below 0.05mA or when the level
of VIN approaches VOUT.
Capacitor Selection
Careful selection of the four external capacitors
CIN, C1, C2, and COUT is important because they
will affect turn-on time, output ripple, and transient
performance. Optimum performance will be
obtained when low equivalent series resistance
(ESR) ceramic capacitors are used. In general,
low ESR may be defined as less than 100mΩ.
Capacitor Characteristics
Ceramic composition capacitors are highly recommended over all other types of capacitors for use with
the AAT3112. Ceramic capacitors offer many advantages over their tantalum and aluminum electrolytic
counterparts. A ceramic capacitor typically has very
low ESR, is lowest cost, has a smaller PCB footprint,
and is non-polarized. Low ESR ceramic capacitors
help to maximize charge pump transient response.
Since ceramic capacitors are non-polarized, they are
not prone to incorrect connection damage.
Equivalent Series Resistance: ESR is an important characteristic to consider when selecting a
capacitor. ESR is a resistance internal to a capacitor that is caused by the leads, internal connections, size or area, material composition, and ambient temperature. Capacitor ESR is typically measured in milliohms for ceramic capacitors and can
range to more than several ohms for tantalum or
aluminum electrolytic capacitors.
Ceramic Capacitor Materials: Ceramic capacitors
less than 0.1µF are typically made from NPO or
COG materials. NPO and COG materials typically
have tight tolerance and are stable over temperature. Large capacitor values are typically composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors, typically greater
than 2.2µF, are often available in low-cost Y5V and
Z5U dielectrics, but large capacitors are not
required in AAT3112 applications.
Capacitor area is another contributor to ESR.
Capacitors that are physically large will have a lower
ESR when compared to an equivalent material
smaller capacitor. These larger devices can improve
circuit transient response when compared to an
equal value capacitor in a smaller package size.
Layout Considerations
High charge pump switching frequencies and large
peak transient currents mandate careful printed circuit board layout. As a general rule for charge pump
boost converters, all external capacitors should be
located as closely as possible to the device package with minimum length trace connections.
Maximize the ground plane around the AAT3112
charge pump and make sure all external capacitors
are connected to the immediate ground plane. A local
component side ground plane is recommended.
3112.2004.12.1.2
13
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Application Circuits
C1 = 1µF
C2 = 1µF
C1+ C1 - C2 +
VIN
VIN
C2 VOUT
CIN=10µF
COUT=10µF
VOUT
EN1
EN2
D1
D2
D3
D4
Flash LED
GND
R2=10
Q1
TPULSE
100ms - 500ms
Figure 1: Flash Application.
C1 = 1µF
C2 = 1µF
C1+ C1 V IN
C2 +
VIN
C2 VOUT
CIN=10µF
COUT=10µF
VOUT
Light/Movie
Mode Enable
EN1
EN2
D1
D2
D3
D4
Flash LED
GND
R3=60 - 100
R2=10
LL4148
R1
TPULSE
Flash Enable
2K
Q1
C3
0.1µF
Figure 2: Movie Mode Light with Flash Function.
14
3112.2004.12.1.2
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Ordering Information
Package
Marking1
Part Number (Tape and Reel)
QFN33-16
LGXYY
AAT3112IVN-4.5-T1
QFN33-16
MNXYY
AAT3112IVN-5.0-T1
Note 1: XYY = assembly and date code.
Sample stock is held on part numbers listed in bold.
Package Information
0.240 ± 0.060
Pin 1 Identification
1
0.975 ± 0.725
Top View
13
9
0.500 ± 0.050
0.025 ± 0.025
Bottom View
0.213 ± 0.036
0.850 ± 0.150
3.000 ± 0.050
0.400 ± 0.100
Pin 1 Dot By Marking
3.000 ± 0.050
5
Side View
All dimensions in millimeters.
3112.2004.12.1.2
15
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
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other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed.
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830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
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3112.2004.12.1.2