|
|
PDF AAT1232 Data sheet ( Hoja de datos )
| Número de pieza | AAT1232 | |
| Descripción | Step-Up Converter | |
| Fabricantes | AAT | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AAT1232 (archivo pdf) en la parte inferior de esta página. Total 17 Páginas | ||
|
No Preview Available !
AAT1232
24V 100mA Step-Up Converter
General Description
Features
SwitchReg™
The AAT1232 is a high frequency, high efficiency
boost converter capable of 24V maximum output
• VIN Range: 2.7V to 5.5V
• Maximum Output: 24V @ 100mA
voltage. The internal power switch can deliver
• True Load Disconnect
100mA load current. It is the ideal power solution to
• Dynamic Voltage Control Options
power OLED, LCD, and CCD applications operat-
• Hysteretic Control
ing from a single cell lithium-ion battery.
— No External Compensation Components
The high switching frequency (up to 2MHz) pro-
vides fast response to load transients with small
external components. The fully integrated control
IC simplifies the design while reducing the total
PCB footprint. The AAT1232 offers a true load dis-
connect feature which isolates the load from the
power source when EN/SET is pulled low. This
eliminates leakage current and maintains zero volt-
age at the output while disabled.
— Excellent Load Transient Response
— High Efficiency at Light Load
• Up to 2MHz Switching Frequency
• Ultra-Small Inductor and Capacitors
• Integrated Low RDS(ON) MOSFET Switches
• Up to 85% Efficiency
• <1µA Shutdown Current
• Integrated Soft Start
• Cycle-by-Cycle Current Limit
• Short-Circuit, Over-Temperature Protection
The output voltage can be dynamically set by acti-
• Available in TSOPJW-12 or TDFN34-16
vating one of two reference levels (FB1 or FB2)
Package
through the SEL logic pin. Optionally, AnalogicTech’s
• -40°C to +85°C Temperature Range
Simple Serial Control™ (S2Cwire™) interface pro-
vides dynamic programmability across a wide output
voltage range through the EN/SET pin.
The
AAT1232
is
available
in
a
Pb-free,
Applicationswww.DataSheet4U.com
thermally-
enhanced 16-pin 3x4mm TDFN low-profile pack-
age or a Pb-free 12-pin TSOPJW package.
• CCD Bias Circuit
• Digital Still Cameras
• LCD Bias Circuit
• Mobile Handsets
• MP3 Players
• OLED Displays
• PDAs and Notebook PCs
Typical Application
Input:
2.7V~5.5V
C1
2.2µF
VP LIN
VIN
AAT1232
SW
PGND
FB1
EN/SET
FB2
SEL GND
L1
2.2µH
D1
Schottky 24V @ 100mA
R1
576kΩ
R2
10.0kΩ
R3
20.0kΩ
C2
2.2µF, 25V
1232.2006.12.1.3
1
1 page  
Typical Characteristics
90
80
70
60
50
40
30
20
0.1
Efficiency vs. Output Current
(VOUT = 18V; R3 = 20kΩ)
VIN = 5V
VIN = 4.2V VIN = 3.6V
1 10
Output Current (mA)
100
90
80
70
60
50
40
30
20
0.1
Efficiency vs. Output Current
(VOUT = 20V; R3 = 20kΩ)
VIN = 5V
VIN = 4.2V VIN = 3.6V
1 10
Output Current (mA)
100
90
80
70
60
50
40
30
20
0.1
Efficiency vs. Output Current
(VOUT = 24V; R3 = 20kΩ)
VIN = 5V
VIN = 4.2V VIN = 3.6V
1 10
Output Current (mA)
100
AAT1232
24V 100mA Step-Up Converter
Output Error vs. Output Current
(VOUT = 18V; R3 = 20kΩ)
1.5
VIN = 5V
1.0
0.5
0.0
-0.5
-1.0
-1.5
0.1
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
1 10
Output Current (mA)
100
Output Error vs. Output Current
(VOUT = 20V; R3 = 20kΩ)
1.5
VIN = 5V
1.0
0.5 VIN = 4.2V
0.0
VIN = 3.6V
-0.5
VIN = 2.7V
-1.0
-1.5
0.1 1 10 100
Output Current (mA)
Output Error vs. Output Current
(VOUT = 24V; R3 = 20kΩ)
1.5
VIN = 4.2V
VIN = 5V
1.0
0.5
0.0
VIN = 3.6V
-0.5
VIN = 2.7V
-1.0
-1.5
0.1
1 10
Output Current (mA)
100
1232.2006.12.1.3
5
5 Page 
diodes are recommended for outputs less than 15V,
while 30V rated Schottky diodes are recommended
for outputs greater than 15V.
The average diode current is equal to the output
current.
IAVG = IOUT
The average output current multiplied by the for-
ward diode voltage determines the loss of the out-
put diode.
PLOSS_DIODE = IAVG · VF
= IOUT · VF
Diode junction temperature can be estimated.
TJ = TAMB + ΘJA · PLOSS_DIODE
The junction temperature should be maintained
below 110ºC, but may vary depending on applica-
tion and/or system guidelines. The diode θJA can
be minimized with additional PCB area on the
cathode. PCB heatsinking the anode may degrade
EMI performance.
The reverse leakage current of the rectifier must be
considered to maintain low quiescent (input) cur-
rent and high efficiency under light load. The recti-
fier reverse current increases dramatically at high
temperatures.
Selecting the Boost Inductor
The AAT1232 controller utilizes hysteretic control
and the switching frequency varies with output load
and input voltage. The value of the inductor deter-
mines the maximum switching frequency of the
AAT1232 boost converter. Increased output induc-
tance decreases the switching frequency, resulting
in higher peak currents and increased output volt-
age ripple. To maintain 2MHz maximum switching
frequency, an output inductor sized from 1.5µH to
2.7µH is recommended.
The switching period is divided between ON and
OFF time intervals.
1232.2006.12.1.3
AAT1232
24V 100mA Step-Up Converter
1
FS
=
TON
+
TOFF
The ON time is the period which the N-channel
power MOSFET is conducting and storing energy
in the boost inductor. Duty cycle is defined as the
ON time divided by the total switching interval.
D=
TON
TON + TOFF
= TON ⋅ FS
The maximum duty cycle can be estimated from
the relationship for a continuous mode boost con-
verter. Maximum duty cycle (DMAX) is the duty
cycle at minimum input voltage (VIN(MIN)).
DMAX
=
(VOUT + VF -
(VOUT +
VIN(MIN))
VF)
Where VF is the Schottky diode forward voltage
and can be estimated at 0.5V. Manufacturer’s
specifications list both the inductor DC current rat-
ing, which is a thermal limitation, and peak inductor
current rating, which is determined by the satura-
tion characteristics. Measurements at full load and
high ambient temperature should be completed to
ensure that the inductor does not saturate or exhib-
it excessive temperature rise.
The output inductor (L) is selected to avoid satura-
tion at minimum input voltage, maximum output load
conditions. Peak current may be calculated from the
following equation, again assuming continuous con-
duction mode. Worst-case peak current occurs at
minimum input voltage (maximum duty cycle) and
maximum load. Switching frequency can be estimat-
ed at 500kHz with a 2.2µH inductor.
IPEAK =
IOUT
(1 - DMAX)
+
DMAX · VIN(MIN)
(2 · FS · L)
The RMS current flowing through the boost induc-
tor is equal to the DC plus AC ripple components.
Under worst-case RMS conditions, the current
waveform is critically continuous. The resulting
11
11 Page | ||
| Páginas | Total 17 Páginas | |
| PDF Descargar | [ Datasheet AAT1232.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AAT1230 | Step-Up Converter | AAT |
| AAT1230-1 | 18V 100mA Step-Up Converter |  Advanced Analogic Technologies |
| AAT1231 | Step-Up DC/DC Converter | AAT |
| AAT1231-1 | Step-Up DC/DC Converter | AAT |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |