PAM2305
1A Step-Down DC-DC Converters
Block Diagram
1.5M
OSC
SLOPE
COMP
+
IAMP
-
VIN
FB
FREQ
SHIFT
R1
-
R2
VIN
OSC
S Q
R Q
RS LATCH
+ - +
PWM
COMP
+
EA
COMP
SWITCHING
LOGIC
AND
BLANKING
CIRCUIT
MAIN
SWITCH
(
PCH
)
ANTI
-
SHOOT
-
THRU
SW
SYNCHRONOUS
RECTIFIER
(
NCH
)
EN
0.6VREF
SHUTDOWN
+
IRCMP
-
GND
Pin Configuration& Marking Information
Top View
SOT23
-
5
VIN 1
BEVYW
Top View
DFN 2x2 6L
Top View
QFN 3x3 16L
SW
SW
NC
SW
16 15 14 13
5
SW
NC
EN
1
6
VOUT/FB
GND
SW
GND 2
EN 3
2
3
5
4
GND
GND
GND
VOUT/FB
1
2
3
4
5
6
7
8
12
VIN
VIN
VIN
VIN
P2305V
XXXYW
11
10
9
4
VOUT/FB
VIN
BE: Product Code
of PAM2305
V: Output Voltage
Y: Year
W: Week
X: Internal Code
GND
Pin Description
Name
VIN
GND
EN
Chip main power supply pin
Ground
Enable control input. Force this pin voltage above 1.5V, enables the chip, and below
0.3V shuts down the device.
VOUT: Output voltage feedback pin, an internal resistive divider divides the output
VOUT/FB
SW
NC
voltage down for comparison to the internal reference voltage.
FB: Feedback voltage to internal error amplifier, the threshold voltage is 0.6V.
The drains of the internal main and synchronous power MOSFET.
No connection
Function
Power Analog Microelectronics
,
Inc
www.poweranalog.com
09/2008 Rev 1.2
2
EN
NC
NC
BEV
YW