AIC1610 AIC [Analog Intergrations Corporation], AIC1610 Datasheet - Page 12

• Manufacturer Part Number: AIC1610
• Description: HIGH EFFICIENCY SYNCHRONOUS STEP-UP DC/DC CONVERTER
• Manufacturer: AIC [Analog Intergrations Corporation]

formance
Shutdown
The whole circuit is shutdown when
At shutdown mode, the current can flow from battery
to output due to body diode of the P-MOSFET. V
falls to approximately Vin-0.6V and LX remains high
impedance. The capacitance and load at OUT de-
termine the rate at which V
can be pulled as high as 6V. Regardless of the volt-
age at OUT.
Selecting the Output Voltage
V
FB pin to OUT/GND due to the use of internal resis-
tor divider in the IC (Fig.32 and Fig.33). In order to
adjust output voltage, a resistor divider is connected
to V
by the following equation:
R5=R6 [(V
Where V
5.5V. The recommended R6 is 240KΩ.
Low-Battery Detection
AIC1610 series contains an on-chip comparator with
50mV internal hysteresis (REF, REF+50mV) for low
battery detection. If the voltage at LBI falls below the
internal reference voltage. LBO ( an open-drain out-
put) sinks current to GND.
Component Selection
1. Inductor Selection
OUT
An inductor value of 22µH performs well in most
applications. The AIC1610 series also work with
inductors in the 10µH to 47µH range. An induc-
tor with higher peak inductor current tends a
higher output voltage ripple (I
capacitor ESR). The inductor’s DC resistance
significantly affects efficiency. We can calculate
the maximum output current as follows:
OUT
can be simply set to 3.3V/5.0V by connecting
, FB, GND (Fig.34). Vout can be calculated
REF
OUT
=1.23V and V
/ V
REF
)-1] .....................................(1)
OUT
OUT
ranging from 1.8V to
decays. Shutdown
PEAK
V
×output filter
SHDN
is low.
OUT
2. Capacitor Selection
3. PCB Layout and Grounding
where I
amps
The output ripple voltage relates with the peak
inductor current and the output capacitor ESR.
Besides output ripple voltage, the output ripple
current also needs to be concerned. A filter ca-
pacitor with low ESR is helpful to the efficiency
and steady state output current of AIC1610 se-
ries. Therefore NIPPON tantalum capacitor
MCM series with 100µF/6V is recommended. A
smaller capacitor (down to 47μ F with higher
ESR) is acceptable for light loads or in applica-
tions that can tolerate higher output ripple.
Since AIC1610’s switching frequency can range
up to 500kHz, it makes AIC1610 become very
sensitive. So careful printed circuit layout is im-
portant for minimizing ground bounce and noise.
IC’s OUT pin should be as clear as possible.
And the GND pin should be placed close to the
ground plane. Keep the IC’s GND pin and the
ground leads of the input and output filter ca-
pacitors less than 0.2in (5mm) apart. In addition,
keep all connection to the FB and LX pins as
short as possible. In particular, when using ex-
ternal feedback resistors, locate them as close
to the FB as possible. To maximize output pow-
er and efficiency and minimize output ripple
voltage, use a ground plane and solder the IC’s
I
……………………………………………………(2)
OUT
V
L=inductor value in µH
η=efficiency (typically 0.9)
t
I
(
OFF
LIM
MAX
IN
=input voltage
=1.0A or 0.65A
OUT(MAX)
=LX switch’ off-time in µS
)
=
V
V
OUT
AIC1610/AIC1611
IN
=maximum output current in



I
LIM
−
t
OFF

 

V
OUT
2
×
−
L
V
IN

 

12

η 
