UM3506QA Datasheet, PDF (2/9 Pages) Union Semiconductor, Inc. – Synchronous Step-Down Converter

Pin Configurations
Top View
UM3506QA
(Top View)
L2
L2
14
13
SW 1
12 PGND
NC 2
11 AGND
MODE 3
10 VIN
FB 4
NC
(PVOUT)
5
6
7
L1 L1
9 EN
8 ^NC
(PVOUT)
3506
M: Month Code
UM3506QA
QFN14 2.5×2.5
Pin Description
Pin Number
1
2
3
4
5, 8
6, 7
9
10
11
12
13, 14
Symbol
SW
NC
MODE
FB
NC
(PVOUT)
L1
EN
VIN
AGND
PGND
L2
Function
This pin is the common switching node of the internal MOSFETs.
It is usually connected to L2 in the PCB.
Not internally connected, can be connected to any other
network in the PCB.
MODE pin=high forces the device to operate in
fixed-frequency PWM mode. Mode pin=low enables
automatic transition from the pulse skipping mode to
fixed-frequency PWM mode.
Feedback input pin. Connect FB to the center point of the external
resistor divider.
Not internally connected, usually connected to power output in
the PCB.
These pins are connected together inside and usually connected
to NC(PVOUT) in the PCB.
Regulator enable control input. Pulling this pin to high enables
the device. Pulling this pin to low forces the device into
shutdown mode. This pin must be terminated.
Power input for the MOSFET switches. Must be closely
decoupled to GND with a 4.7μF or greater ceramic capacitor.
Analog ground. This is the ground for the internal control
circuitry, and the ground return for external feedback voltage
divider. It must be connected to the quiet point of the ground.
Power ground. Connect this pin to the ground electrode of the
input and output filter capacitors closely.
These pins are connected together inside and usually connected
to SW in the PCB.
Ordering Information
Part Number
UM3506QA
Packaging Type
QFN14 2.5×2.5
Marking Code
3506
Shipping Qty
3000pcs/13Inch
Tape & Reel
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http://www.union-ic.com Rev.01 Oct.2016
2/9