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
=2A. (Typ.)
- Soft-start time set-up externally type possible
- Current limit and thermal shutdown protection
- Pb-Free Package: SOT23-5, SON-6(3
30.8mm)
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
3
2
5
4
CE/SS
V
OUT
V
CC
GND
SOT23-5
FB
(Top View)
AP1604A
SON-6
1
2
3
4
5
6
GND
CE
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
AP1604
PWM/PFM Dual Mode Step-down DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.1 Jun. 27, 2005
2/7
Ordering Information
AP1604 X X X
W: SOT23-5
SN: SON-6 (3*3*0.8mm)
Packing
A : Taping
Package
A: AP1604A
Version
Block Diagrams
Phase
Compensation
Vref with
CE
+
-
PWM/PFM
Controller
+
-
Ramp Wave
Generator,
OSC
V
OUT
CE/SS
GND
V
CC
PWM
Comparator
FB
Current Limit
Soft
Start
ERR
AMP
SV
CC
Absolute Maximum Ratings
Ta=25C
Symbol
Parameter
Ratings
Units
V
CC
/SV
CC
V
IN
Pin Voltage
-0.3 ~ 6.5
V
V
OUT
V
OUT
Pin Voltage
-0.3 ~ V
IN
+0.3 V
V
FB
FB Pin Voltage
-0.3 ~ V
IN
+0.3 V
V
CE/SS
CE/SS Pin Voltage
-0.3 ~ V
IN
+0.3 V
Pd
Continuous Total
Power Dissipation
Internal limited
Topr
Operating Ambient
Temperature
-25 ~ +80
C
Tstg
Storage Temperature
-40 ~ +125
C
AP1604
PWM/PFM Dual Mode Step-down DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.1 Jun. 27, 2005
3/7
Electrical Characteristics
V
IN
=5V, V
OUT
2V, Load=300mA, Ta=25C
Sym.
Parameter
Conditions
Min.
Typ. Max. Units
V
FB
FB
0.975
1.0 1.025 V
V
IN
Input
Voltage
2.2 - 5.5 V
Line
Regulation V
IN
=2.2~5.5V, Load=10mA
-
-
0.12
%
Load
Regulation I
OUT
=10~800mA -
-
1.2
%
V
UVLO
UVLO Voltagemin.
operating voltage
V
CC
, voltage required to maintain H at
V
OUT
- - 2 V
I
CC
Operating
Current
CE/SS=V
IN
,
No Load
-
100
150
A
I
CCQ
Supply
Current
No external components,
CE/SS=V
IN
,
V
FB
=1.2V
- 90
120
A
I
STB
Stand-by
Current
No external components,
CE/SS=0V,
V
FB
=0V
- 2 - A
I
CL
Current
Limit
peak current
V
IN
=5V, V
OUT
=2V
800
1000 1200 mA
Fosc Oscillator
Frequency Load=300mA,
V
IN
=5V, V
OUT
=2V 500
600
700
kHz
MAXDTY Maximum Duty Ratio
85
90
-
%
PFMDTY PFM Duty Ratio
No load
15
25
35
%
V
CEH
CE/SS "High" Voltage
Apply 1.4V (min.) to CE/SS, determine
V
OUT
"High"
1.4 - - V
V
CEL
CE/SS "Low" Voltage Same as V
CEH
, determine V
OUT
/"Low" -
-
0.6
V
EFFI Efficiency
V
CC
=5V, V
OUT
=3.3V, Load=300mA
-
93
-
%
Rdson Rdson
Condition
I
OUT
=300mA, V
IN
=5V, V
OUT
=2V -
350
450
m
Typical Performance Characteristics
Vcc v.s. Operating Current
Vcc v.s. Quiescent Current
0
20
40
60
80
100
120
140
160
180
200
2.5
3
3.5
4
4.5
5
5.5
Vcc (V)
O
perat
ing C
u
rrent
(uA)
0
20
40
60
80
100
120
140
160
180
200
2.5
3
3.5
4
4.5
5
5.5
Vcc (V)
Quiescen
t
C
u
rrent
(uA)
AP1604
PWM/PFM Dual Mode Step-down DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.1 Jun. 27, 2005
4/7
Typical Performance Characteristics (Continued)
Vcc v.s. Stand-by Current
Vcc v.s. Frequency
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
2.5
3
3.5
4
4.5
5
5.5
Vcc (V)
St
and-by
Current
(uA)
500
520
540
560
580
600
620
640
660
680
700
2.5
3
3.5
4
4.5
5
5.5
Vcc (V)
F
r
equenc
y (KH
z
)
Vcc v.s. Current Limit
Vcc v.s. R
DS(ON)
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
3
3.5
4
4.5
5
5.5
Vcc (V)
C
u
rre
n
t
L
i
mit
(A
)
Current Limit
Vout=2V
0
100
200
300
400
500
600
2.5
3
3.5
4
4.5
5
5.5
R
DS
(
O
N)
(m
)
Vcc (V)
Line Regulation
Load Regulation
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
2.5
3
3.5
4
4.5
5
5.5
Vcc (V)
V / V
OUT
(%)
-3
-2
-1
0
1
2
3
0
100 200 300 400 500 600 700 800
Load (mA)
V /
V
OUT
(%)
AP1604
PWM/PFM Dual Mode Step-down DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.1 Jun. 27, 2005
5/7
Typical Application Circuit
0.1uF
V
IN
FB
V
CC
GND
10uH
AP1604A
V
OUT
CE/SS
68uF
2.2V ~ 5.5V
B240A
R2
R1
0.1uF 68uF
V
OUT
10nF
100nF
~
1M
Vout = 1
(1 +
R1
R2
)
R1=100K ~ 200K
Marking Information
(1) SOT23-5L
XX : Identification code
(See Appendix)
Y : Year: 0-9
M : Month: A~L
SOT23-5L
XX Y M
7
1
2
3
4
5
Appendix
Part Number
Package
Identification
Code
AP1604A SOT23-5
ER
(2) SON-6L (3*3*0.8mm)
Date Code
Year: 0~9
Month: A~L
Identification Code
( See the table )
XX
XX
Appendix
Part Number
Package
Identification
code
AP1604A
SON-6L
(3*3*0.8mm)
S4
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