AP1601
Step-Up 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 Apr. 14, 2005
1/9
Features
-A Guaranteed Start-Up from less than 0.9 V.
-High Efficiency.
-Low Quiescent Current.
-Less Number of External Components needed.
-Low Ripple and Low Noise.
-Space Saving Packages: MSOP-8L and
MSOP-10L.
Applications
-Pagers.
-Cameras.
-Wireless Microphones.
-Pocket Organizers.
-Battery Backup Suppliers.
-Portable Instruments.
General Description
The AP1601 is a high efficiency step-up DC/DC
converter for applications using 1 to 4 NiMH battery
cells. Only three external components are required
to deliver a fixed output voltage of 3.3V or 5V. The
AP1601 starts up from less than 0.9V input with
1mA load. Pulse Frequency Modulation scheme
brings optimized performance for applications with
light output loading and low input voltages. The
output ripple and noise are lower compared with the
circuits operating in PSM mode.
The PFM control circuit operating in 100KHz (max.)
switching rate results in smaller passive
components. The space saving MSOP packages
make the AP1601 an ideal choice of DC/DC
converter for space conscious applications, like
pagers, electronic cameras, and wireless
microphones.
Pin Assignments
1
3
2
4
8
6
7
5
MSOP-8L
FB
LBI
REF
OUT
LX
GND
LBO
SHDN
1
3
2
10
8
9
MSOP-10L
FB
LBI
OUT
LX
GND
4
7
CLSEL
5
6
REF
BATT
SHDN
LBO
Pin Descriptions
Name
Description
FB
Use a resistor network to set the output
voltage from +2.0V to +5.5V.
If FB=Vout, Vout=3.3V fix voltage
FB=GND, Vout=5V fix voltage
LBI
Low-Battery Comparator Input. Internally set
to trip at +1.30V.
LBO
Open-Drain Low-Battery Comparator Output.
Connect LBO to OUT through a 100k
resistor. Output is low when V
LBI
is <1.2V.
LBO
is high impedance during shutdown.
REF
1.2V Reference Voltage. Bypass with a 0.1F
capacitor.
OUT
Power Output. OUT provides bootstrap power
to the IC.
LX
N-Channel and P-Channel Power MOSFET
Drain
GND Ground
SHDN
Shutdown Input. Drive high (>80% of V
OUT
) for
operating mode. Drive low (<20% of V
OUT
) for
shutdown mode. Connect to OUT for normal
operation.
CLSEL
Current-Limit Select Input. CLSEL = OUT sets
the current limit to 0.8A. CLSEL = GND sets
the current limit to 0.4A.
BATT
Battery Input and Damping Switch
Connection. If damping switch is unused,
leave BATT unconnected.
AP1601
Step-Up DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev. 1.1 Apr. 14, 2005
2/9
Ordering Information
Package
M8: MSOP-8L
AP1601
X
X X
Packing
Blank : Tube
A : Taping
M10: MSOP-10L
Lead Free
Blank : Normal
L : Lead Free Package
Block Diagram
+
-
+
-
+
-
S
Q
R
F/F
TRIG
One-Shot
Q
One-Shot
Q
TRIG
Maximum
On-Time
One-Shot
Error
Amplifier
Current-Limit
Amplifier
Low-Battery
Comparator
Reference
Zero
Crossing
Amplifier
Minimum
Off-Time
One-Shot
LBO
LBI
+
-
+
-
Damping
Switch
OUT
LX
GND
BATT
FB
REF
0.1uF
22uH
R1
200
R5
R6
0.1uF
+
47uF
+
47uF
+
SHDN
CLSEL
V
OUT
R2
100k
V
IN
R3
R4
P
N
V
IN
EN
AP1601
Step-Up DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev. 1.1 Apr. 14, 2005
3/9
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
CC
Supply Voltage (OUT to GND)
-0.3 to 8.0
V
V
BATT
Battery Voltage (Batt to GND)
-0.3 to 6.0
V
LBI, REF, FB, CLSEL to GND
-0.3 to V
OUT
+0.3 V
V
SW
Switch Voltage (LX to GND)
-0.3 to V
OUT
+0.3 V
I
OUT
Output Current (OUT)
-1.5 to +1.5
A
V
LBO
LBO to GND
6.0
V
I
SW
Switch
Current
(LX)
-1.5 to +1.5
A
T
ST
Storage Temperature Range
-65 to +150
o
C
T
OT
Operation Temperature Range
-40 to +80
o
C
Electrical Characteristics
(V
BATT
= 2V, FB = OUT (V
OUT
= 3.3V), R
L
= , T
A
= 0C to +85C, unless otherwise noted. Typical values are at T
A
= +25C.)
Symbol
Parameter
Conditions
Min.
Typ. Max.
Unit
Minimum
Input
Voltage
-
0.9
- V
V
IN
Operating
Voltage
T
A
= +25C
1.1
-
5.5
V
Start-Up
Voltage
T
A
= +25C,
RL = 3k
(Note 1)
- 0.9 1.1 V
Start-Up Voltage Tempco
-
-2
-
mV/C
Output
Voltage
Range
2 -
5.5 V
AP1601
(CLSEL=OUT)
300
420 -
(V
OUT
= 3.3V)
AP1601
(CLSEL=GND)
150
220 -
AP1601
(CLSEL=OUT)
180
285 -
I
OUT
Steady-State Output
Current (Note2)
(V
OUT
= 5V)
AP1601
(CLSEL=GND)
90 130 -
mA
V
REF
Reference
Voltage
I
REF
=0 1.176
1.2
1.224
V
TEMPCO
Reference
Voltage
Tempco
- 0.024 - mV/C
V
REF_LOAD
Reference Voltage Load
Regulation
I
REF
=0 to 20A
-
30
80
mV
V
REF_LINE
Reference Voltage Line
Regulation
V
OUT
=2V to 5.5V
-
0.08
2.5
mV/V
FB, LB1 Input Threshold
1.176
1.2
1.224
V
R
DS(ON)
Internal NFET, PFET
On-Resistance
I
LX
=100mA -
0.3
0.6
AP1601 (CLSEL=OUT)
0.80
1
1.20
I
LIM
LX Switch Current Limit
(NFET)
AP1601 (CLSEL=GND)
0.4
0.5
0.65
A
I
LEAK
LX Leakage Current
I
LX
=0, 5.5V; V
OUT
=5.5V -
0.05
1
A
AP1601
Step-Up DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev. 1.1 Apr. 14, 2005
4/9
Electrical Characteristics (Continued)
(V
BATT
= 2V, R
L
=, T
A
= 0C to +85C, unless otherwise noted. Typical values are at T
A
= +25C .)
Symb
ol
Parameter
Conditions
Min.
Typ.
Max.
Unit
Operating Current into OUT V
FB
=1.4V, V
OUT
=3.3V
- 16 35
A
Shutdown Current into OUT
SHDN
=GND
- 0.1 1
A
V
OUT
=3.3V, I
LOAD
=200mA
- 90 -
Efficiency
V
OUT
=2V, I
LOAD
=1mA
- 85 -
%
t
ON
LX Switch On-Time
V
FB
=1V, V
OUT
=3.3V
3 4 7
s
t
OFF
LX Switch Off-Time
V
FB
=1V, V
OUT
=3.3V
0.8 1 1.2
s
I
FB
FB Input Current
V
FB
=1.4V
- 0.03 50
nA
I
LBI
LBI Input Current
L
LBI
=1.4V
- 1 50
nA
I
CLSEL
CLSEL Input Current
AP1601, CLSEL=OUT
- 1.4 3
A
I
SHDN
SHDN Input Current
V
SHDN
=0 or V
OUT
- 0.07 50
nA
LBO
Low Output Voltage
L
LBI
=0, I
SINK
=1mA -
0.2
0.4
V
I
LBO
LBO
Off Leakage Current
V
LBO
=5.5V, L
LBI
=5.5V
- 0.07 1
A
Damping Switch Resistance
AP1601, V
BATT
=2V
- 88
150
V
IL
- -
0.2
V
OUT
V
IH
SHDN Input Voltage
0.8 V
OUT
- -
V
V
IL
- -
0.2
V
OUT
V
IH
CLSEL Input Voltage
0.8 V
OUT
- -
V
Note 1: Start-up voltage operation is guaranteed with the addition of a Schottky MBR0520 external diode between the input and output.
Note 2: Steady-state output current indicates that the device maintains output voltage regulation under load.
Typical Application Circuit
SHDN
LBO
LX
OUT
FB
REF
LBI
GND
0.1uF
Low- Battery
Detect OUT
22uH
220uF
+
100uF
+
V
IN
ON
OFF
Adj Output (1.8V to 4.0V)
up to 300 mA
Low- Battery
Detect In
R5
R6
Vout=1.2 (1+ )
R6
R5
R6 Suggest 100K~200K
FB=Vout, Vout=3.3V
FB=GND, Vout=5V
AP1601
Step-Up DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev. 1.1 Apr. 14, 2005
5/9
Typical Performance Characteristics
REFERENCE OUTPUT VOLTAGE
v.s. TEMPERATURE
1.14
1.15
1.16
1.17
1.18
1.19
1.2
1.21
-40
-20
0
20
40
60
80
100
TEMPERATURE (C)
REFERENCE OUTPUT
VOLTAGE (V)
MAXIMUM OUTPUT CURRENT
v.s. INPUT VOLTAGE (V
OUT
=3.3V)
0
100
200
300
400
500
600
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
INPUT VOLTAGE (V)
MAXIMUM OUTPUT
CURRENT (mA)
START-UP VOLTAGE
v.s. LOAD CURRENT
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.01
0.1
1
10
100
LOAD CURRENT (mA)
START-UP
VOLTAGE (V)
Without Diode
With Diode
NO-LOAD BATTERY CURRENT
v.s.
INPUT BATTERY VOLTAGE
0
20
40
60
80
100
120
140
160
0.5
1
1.5
2
2.5
3
INPUT BATTERY VOLTAGE (V)
INPUT BATTERY
CURRENT (uA)
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