as1353 austriamicrosystems, as1353 Datasheet - Page 10

• Manufacturer Part Number: as1353
• Description: 150ma Low Dropout Regulator, Reverse Battery Protection, Low Noise Bypass Pin
• Manufacturer: austriamicrosystems

AS1353/AS1356
Data Sheet
9 Typical Application
Figure 13. Typical Application Diagrams
Capacitor Selection and Regulator Stability
Ceramic capacitors are highly recommended as they offer distinct advantages over their tantalum and aluminum elec-
trolytic components.
For stable operation with load currents up to 150mA over the entire device temperature range, use a 1µF (min)
ceramic output capacitor with an ESR <0.2Ω.
Use large output capacitor values (10µF max) to reduce noise and improve load transient-response, stability and
power-supply rejection.
Note: Some ceramic capacitors exhibit large capacitance and ESR variations with variations in temperature. Z5U
Power Supply Rejection Ratio
The AS1353/AS1356 are designed to deliver low dropout voltages and low quiescent currents. Power-supply rejection
is 60dB (typ) at low frequencies. To improve power supply-noise rejection and transient response, increase the values
of the input and output bypass capacitors (see Figure 13).
The Typical Operating Characteristics (page 6) show the device line- and load-transient responses. See the Power-
Supply Rejection Ratio vs. Frequency graph in the Typical Operating Characteristics section (page 6) for further
details.
Dropout Voltage
For standard products with output voltage greater than the minimum V
ferential (dropout voltage) determines the lowest usable supply voltage. This determines the useful end-of-life battery
voltage in battery-powered systems.
The dropout voltage is a function of the P-MOSFET drain-to-source on-resistance multiplied by the load current, and is
calculated by:
Where:
R
I
See Typical Operating Characteristics (page 6) for further information.
www.austriamicrosystems.com
OUT
DS(ON)
On
Off
is the supply current.
+2.5 to
+5.5V
0.01µF
and Y5V capacitors may be required to ensure stability at temperatures below T
capacitors, a 1µF capacitor should be sufficient at all operating temperatures.
C
is the drain-to-source on-resistance.
BP
1µF
C
- Ty p i c a l A p p l i c a t i o n
IN
BP
SHDNM
IN
AS1353
GND
OUT
V
DROPOUT
C
1µF
OUT
Preset Output
1.5 to 3.6V,
150mA
= V
IN
- V
Revision 1.03
OUT
= R
On
Off
+2.5 to
+5.5V
DS(ON)
1µF
C
x I
IN
IN
OUT
(2.5V), the minimum input-output voltage dif-
SHDNM
GND
IN
AS1356
OUT
POK
AMB
= -10ºC. With X7R or X5R
100kΩ
C
1µF
OUT
Preset Output
1.5 to 3.6V,
processor
To Micro-
150mA
10 - 13
(EQ 3)