AS1326
Datasheet - Pinout
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
ISET
REF
GND
FB
1
2
3
4
5
10 ONN/ON
9
8
7
6
POUT
LX
AS1326A/
AS1326B
PGND
CLK/SEL
OUT
11
Pin Descriptions
Table 2. Pin Descriptions
Pin Number
Pin Name
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.
1
ISET
2
3
REF
Ground. Connect this pin to PGND using a short trace. The exposed pad can be
used for this routing.
GND
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 (see Figure 19
on page 11).
4
5
FB
OUT
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.
6
CLK/SEL
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
7
8
9
PGND
LX
Power Output. P-channel synchronous rectifier source.
POUT
Enable Low (AS1326A only). Must be connected to GND for normal operation.
0 = The AS1326A is on.
ONN
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.
10
11
ON
NC
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