AS1326
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
ISET 1
REF 2
GND 3
FB 4
OUT 5
11
10 ONN/ON
9 POUT
8 LX
7 PGND
6 CLK/SEL
Pin Descriptions
Pin Number
1
2
Table 2. Pin Descriptions
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Pin Name
ISET
REF
3
4
GND
FB
5
OUT
6
CLK/SEL
7
8
9
PGND
LX
POUT
ONN
ON
NC
Revision 1.05
Description
N-Channel Current-Limit Control.
For maximum current limit, connect to pin REF.
To reduce current, supply a voltage between pin REF and GND using a resistive
voltage-divider. If soft-start is desired, connect a capacitor from this pin to GND.
1.250V Internal Reference Bypass.
Connect a 10nF ceramic bypass capacitor to
GND. Up to 50µA of external load current is allowed.
Ground.
Connect this pin to PGND using a short trace. The exposed pad can be
used for this routing.
DC-DC Converter Feedback Input.
To set fixed output voltage of +3.3V, connect
this pin to GND. For adjustable output of 2.5 to 5.0V, connect to a resistor-divider
network from pin OUT to GND. The set point for this pin is 1.24V.
IC Power, Supplied from the Output.
Bypass this pin to GND with a 330nF
ceramic capacitor, and connect to POUT with a 10Ω series resistor
Clock Input for the DC-DC Converter.
This pin is also used to program the
operational mode as follows:
0 = Normal operation – the AS1326A operates at a fixed frequency, and switches
into automatic powersave operation if the load is minimized.
1 = Forced-PWM mode – the AS1326A operates in low-noise, constant-frequency
mode at all loads.
Clocked = Forced-PWM mode with the internal oscillator synchronized to this pin in
500 to 1200kHz range.
N-Channel Power MOSFET Switch Source
Inductor Connection
Power Output.
P-channel synchronous rectifier source.
Enable Low (AS1326A
only). Must be connected to GND for normal operation.
0 = The AS1326A is on.
1 = The AS1326A is off.
Enable High (AS1326B
only). Must be connected to OUT for normal operation.
0 = The AS1326B is off.
1 = The AS1326B is on.
Exposed Pad.
This pad is not connected internally. It can be used for ground
connection between GND and PGND.
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AS1326A/
AS1326B
id
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