AP1604
PWM/PFM Dual Mode Step-down DC/DC Converter


This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev.1.1 Jun. 27, 2005
1/7

„ Features

- Input voltage range: 2.2V~5.5V (V
OUT
type)
- Oscillator frequency: 600KHz (Typ.)
- Internal reference: 1.0V (Typ.)
- High efficiency: 93% (Typ .)
- Stand-by capability: I
STB
=2µA. (Typ.)
- Soft-start time set-up externally type possible
- Current limit and thermal shutdown protection
- Pb-Free Package: SOT23-5, SON-6(3×3×0.8mm)

„ Applications

● Electronic Information Organizers
● Palmtops
● Cellular and portable phones
● Portable Audio Systems
● Various Multi-function Power Supplies

„ General Descriptions

The AP1604 series are multi-functional step-down
DC/DC converters with built-in speed, low ON
resistance drivers. It is capable to deliver more than
800mA output current with external coil, diode and
capacitor.

Output voltage is set-up by the external resistors. (±
2.5% accuracy). The 600KHz AP1604 that can
work out with small value external components
comes out more compact board.

The device switches to and works under PFM mode
with light loads. It keeps at high efficiency for both
light loads and large output current.

AP1604 can be soft-start with a proper capacitor
connected between CE/SS pin and ground. The
stand-by current is less than 2uA when CE/SS pin
is at “LOW” status. The device is forced to switch
off as the voltage at that pin is lower than the
stipulated voltage.


„ Pin Assignment

1 32
5 4
CE/SS
V
OUT
V
CC
GND
SOT23-5
FB
(Top View)
AP1604A

SON-6
1
2
3 4
5
6
GNDCE
FB V
OUT
V
CC
SV
CC



„ Pin Descriptions

Pin Name Function
V
OUT
Output Voltage
V
CC
Input Supply
GND Ground
CE/SS Chip Enable / Soft Start
FB Feedback pin
SV
CC
Signal Power for SON only