AATIAN70 Datasheet, PDF (1/10 Pages) SiGe Semiconductor, Inc. – CMOS Low Voltage LDO Linear Regulator

EV-137
AAT3244 EVAL: 300mA Adjustable Dual
CMOS Low Voltage LDO Linear Regulator
Introduction
The AAT3244 evaluation board provides a platform for test and evaluation of the AAT3244 Dual CMOS Low
Voltage LDO Linear Regulator. The evaluation board demonstrates suggested size and placement of external
components to achieve the best performance. The external components are limited and selected for small size
to suit portable devices applications, while the layout has been optimized to achieve low output noise and high-
est possible power supply ripple rejection performance with the TSOPJW-12 package. The design operates
across an input voltage range from 1.8V to 5.5V and provides an ultra-low adjustable output voltage from 3.6V
to 0.6V.
The AAT3244 Evaluation Board provides dual inputs and outputs at 300mA output current per LDO. Resistors
R1, R2 and R3, R4 program the outputs to regulate at a voltage higher than 0.6V. The suggested value for R2
and R4 is 59kΩ. Table 1 summarizes the resistor values for various output voltages. The Power OK open drain
outputs are pulled up by 100kΩ resistors R5, R6. Connecting ENA or ENB to INA or INB will turn on the part
while connecting ENA or ENB to GND will disable either the A or B channel.
Schematic and BOM
VCC
POKA
POKB
INA
INB
C3
1uF
R6
100K
R5
100K
12 _POKA
7
POKB
2 _INA
C1
1uF
ENA
11
ENA
ON/OFF
5
INB
8
C2
ENB
ENB
1uF
ON/OFF
TSOPJW-12
9
VCC
OUTA
FBA
1
R1
Adj.
3
R2
59K
AAT3244
(Optional)
C6
22pF
C4
2.2uF
OUTA
GND
10
OUTB
FBB
6
R3
Adj.
4
R4
59K
(Optional)
C7
22pF
C5
2.2uF
OUTB
Figure 1: AAT3244 Evaluation Board Schematic (AAT3244 ITP-DB1)
Symbol
U1
C1, C2, C3
C4, C5
C6, C7
R1, R3
R2, R4
Description
AAT3244 TSOPJW-12
1μF 10V 0603
2.2μF 10V 0603
22pF 10V 0603 (Optional)
See Table 2; 10V 0603
59kΩ 10V 0603
Table 1: AAT3244 Evaluation Board Bill of Materials (BOM).
EV-137.2007.08.1.0
1