AS1330
Datasheet - Application Information
9 Application Information
The AS1330 is ideal for space critical applications where ultra-small size is critical as in medical diagnostic equipment,
hand-held instruments, digital cameras, MP3 players, GPS receivers, and PC or Memory cards.
Along with Figure 1 on page 1, Figure 20, Figure 21 and Figure 22 on page 11depict a few of the many applications for
which the AS1330 converters are perfectly suited.
Adjustable Output Voltage
The integrated error amplifier is an internally compensated trans-conductance (gm) type (current output). The internal
0.8V reference voltage is compared to the voltage at pin FB to generate an error signal at the output of the error ampli-
fier. A voltage divider from VOUT to GND programs the output voltage from 1.8 to 3.0V via pin FB as:
VOUT = 0.8V(1 + (R1/R2))
(EQ 1)
Sense Function
The AS1330 offers a sense function for monitoring a voltage (e.g.: the battery voltage). The sense function can work in
three different modes:
- SENSE to GND: The POK is related to VOUT (see Figure 22 on page 11).
- SENSE to VIN: If the pin SENSE is directly connected to pin VIN, the internal reference voltage (0.8V) is used to
compare it with VIN. The POK goes high when the voltage on SENSE is above 0.8V and low when the voltage on
SENSE is below 0.8V (see Figure 21 on page 11).
- SENSE to a voltage divider: With the voltage divider the threshold voltage on which the POK reacts can be set. If
the monitored voltage is higher then the user set threshold voltage the POK is high, when the monitored voltage
is lower the POK goes low (see Figure 20). The threshold voltage can be set with the following equation:
Vthreshold = 0.8V(1 + (RIN1/RIN2))
(EQ 2)
Figure 20. AS1330 - Boost Converter, Single AA Cell to 3.0V fixed Output Voltage
L1
1µH
SW
AA Battery
VOUT
3.0V
VOUT
VIN
EN
C1
4.7µF
C2
4.7µF
Vthreshold
1.2V
AS1330-3.0
POK
FB
On
Off
RIN1
320kΩ
SENSE
GND
RIN2
680kΩ
www.austriamicrosystems.com/DC-DC_Step-Up/AS1330
Revision 1.04
10 - 16
AMSCO [ AMS(艾迈斯) ]
