AAT1230ITP-T1 Analogic Tech, AAT1230ITP-T1 Datasheet - Page 10

• Manufacturer Part Number: AAT1230ITP-T1
• Description: Switching Converters, Regulators & Controllers 18V 100mA Step-Up Converter
• Manufacturer: Analogic Tech

Specifications of AAT1230ITP-T1

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Application Information
Selecting the Output Diode
To ensure minimum forward voltage drop and no
recovery, high voltage Schottky diodes are consid-
ered the best choice for the AAT1230/1230-1 boost
converter.
sized to maintain acceptable efficiency and reason-
able operating junction temperature under full load
operating conditions.
package thermal resistance (θ
factors to consider in selecting a diode. The diode's
published current rating may not reflect actual oper-
ating conditions and should be used only as a com-
parative measure between similarly rated devices.
20V rated Schottky diodes are recommended for
outputs less than 15V, while 30V rated Schottky
diodes are recommended for outputs greater than
15V.
The switching period is divided between ON and
OFF time intervals.
During the ON time, the N-channel power MOS-
FET is conducting and storing energy in the boost
inductor.
power MOSFET is not conducting. Stored energy is
10
JP1
JP2
Enable
Select
During the OFF time, the N-channel
The AAT1230/1230-1 output diode is
3
2
1
3
2
1
F
1
S
10K
R4
= T
Forward voltage (V
ON
2.2μF
Figure 1: AAT1230/1230-1 Demo Board Schematic.
VIN
C1
+ T
JA
) are the dominant
OFF
U1 AAT1230/1230-1 TSOPJW12
C1 10V 0603 2.2μF
C2 25V 0805 2.2μF
D1 30V 0.5A MBR0530T1 SOD-123
L1 2.2μH SD3814-2R2
R1 78.7k 0603
R2 562 0603
R3 4.99k 0603
R4 10k 0603
1
2
3
4
5
6
U1
F
VP
EN/SET
SEL
VIN
N/C
SW
) and
PGND
GND
FB1
FB2
SW
LIN
12
11
10
9
8
7
transferred from the input battery and boost induc-
tor to the output load through the output diode.
Duty cycle is defined as the ON time divided by the
total switching interval.
The maximum duty cycle can be estimated from
the relationship for a continuous mode boost con-
verter.
cycle at minimum input voltage (V
The average diode current during the OFF time can
be estimated.
The following curves show the V
for different Schottky diodes (100°C case). The V
of the Schottky diode can be estimated from the
average current during the off time.
18V 100mA Step-Up Converter
2.2μH
L1
Maximum duty cycle (D
R3
4.99k
D
D1
Schottky
MAX
D =
I
AVG(OFF)
562
R2
AAT1230/1230-1
= T
=
T
V
ON
ON
OUT
T
=
⋅ F
+ T
ON
V
R1
78.7k
- V
1 - D
OUT
S
OFF
VOUT
I
IN(MIN)
OUT
MAX
MAX
IN(MIN)
F
C2
2.2μF
characteristics
) is the duty
1230.2007.06.1.6
).
F