AP1601
Step-Up DC/DC Converter
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.
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.
Applications
-Pagers.
-Cameras.
-Wireless Microphones.
-Pocket Organizers.
-Battery Backup Suppliers.
-Portable Instruments.
Pin Assignments
Pin Descriptions
Name
Description
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
Low-Battery Comparator Input. Internally set
to trip at +1.30V.
Open-Drain Low-Battery Comparator Output.
Connect
LBO
to OUT through a 100kΩ
resistor. Output is low when V
LBI
is <1.2V.
LBO
is high impedance during shutdown.
1.2V Reference Voltage. Bypass with a 0.1µF
capacitor.
Power Output. OUT provides bootstrap power
to the IC.
N-Channel and P-Channel Power MOSFET
Drain
Ground
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.
Current-Limit Select Input. CLSEL = OUT sets
the current limit to 0.8A. CLSEL = GND sets
the current limit to 0.4A.
Battery
Input
and
Damping
Switch
Connection. If damping switch is unused,
leave BATT unconnected.
FB
LBI
LBO
REF
1
2
3
4
MSOP-8L
8
7
6
5
OUT
LX
GND
SHDN
FB
LBI
LBO
FB
LBI
LBO
CLSEL
REF
1
2
3
4
5
10
9
8
7
6
OUT
LX
GND
BATT
SHDN
REF
OUT
LX
GND
SHDN
MSOP-10L
CLSEL
BATT
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
AP1601
Step-Up DC/DC Converter
Absolute Maximum Ratings
Symbol
V
CC
V
BATT
V
SW
I
OUT
V
LBO
I
SW
T
ST
T
OT
Parameter
Supply Voltage (OUT to GND)
Battery Voltage (Batt to GND)
LBI, REF, FB, CLSEL to GND
Switch Voltage (LX to GND)
Output Current (OUT)
LBO to GND
Switch Current (LX)
Storage Temperature Range
Operation Temperature Range
Rating
-0.3 to 8.0
-0.3 to 6.0
-0.3 to V
OUT
+0.3
-0.3 to V
OUT
+0.3
-1.5 to +1.5
6.0
-1.5 to +1.5
-65 to +150
-40 to +80
Unit
V
V
V
V
A
V
A
o
C
o
C
Electrical Characteristics
(V
BATT
= 2V, FB = OUT (V
OUT
= 3.3V), R
L
=
∞,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
Symbol
V
IN
Parameter
Minimum Input Voltage
Operating Voltage
Start-Up Voltage
Start-Up Voltage Tempco
Output Voltage Range
Conditions
T
A
= +25°C
T
A
= +25°C,
RL = 3k
Ω
(Note 1)
Min.
-
1.1
-
-
2
Typ.
0.9
-
0.9
-2
-
420
220
285
130
Max.
-
5.5
1.1
-
5.5
-
-
Unit
V
V
V
mV/°C
V
(V
OUT
= 3.3V)
I
OUT
Steady-State Output
Current
(Note2)
(V
OUT
= 5V)
V
REF
TEMPCO
V
REF_LOAD
V
REF_LINE
Reference Voltage
Reference Voltage Tempco
Reference Voltage Load
Regulation
Reference Voltage Line
Regulation
FB, LB1 Input Threshold
Internal NFET, PFET
On-Resistance
LX Switch Current Limit
(NFET)
LX Leakage Current
I
REF
=0
I
REF
=0 to 20µA
AP1601
(CLSEL=OUT)
AP1601
(CLSEL=GND)
AP1601
(CLSEL=OUT)
AP1601
(CLSEL=GND)
300
150
180
90
mA
-
-
V
mV/°C
mV
mV/V
V
Ω
A
μA
1.176 1.2 1.224
-
0.024
-
-
-
1.176
30
0.08
1.2
0.3
1
0.5
0.05
80
2.5
1.224
0.6
1.20
0.65
1
V
OUT
=2V to 5.5V
R
DS(ON)
I
LIM
I
LEAK
I
LX
=100mA
AP1601 (CLSEL=OUT)
AP1601 (CLSEL=GND)
I
LX
=0, 5.5V; V
OUT
=5.5V
-
0.80
0.4
-
Anachip Corp.
www.anachip.com.tw
3/9
Rev. 1.1 Apr. 14, 2005
AP1601
Step-Up DC/DC Converter
Electrical Characteristics (Continued)
(V
BATT
= 2V, R
L
=∞,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C .)
Symb
ol
Parameter
Operating Current into OUT
Shutdown Current into OUT
Efficiency
Conditions
V
FB
=1.4V, V
OUT
=3.3V
SHDN
=GND
V
OUT
=3.3V, I
LOAD
=200mA
V
OUT
=2V, I
LOAD
=1mA
V
FB
=1V, V
OUT
=3.3V
V
FB
=1V, V
OUT
=3.3V
V
FB
=1.4V
L
LBI
=1.4V
AP1601, CLSEL=OUT
Min.
-
-
-
-
3
0.8
-
-
-
Typ.
16
0.1
90
85
4
1
0.03
1
1.4
Max.
35
1
-
-
7
1.2
50
50
3
Unit
µA
µA
%
µs
µs
nA
nA
µA
t
ON
t
OFF
I
FB
I
LBI
I
CLSEL
LX Switch On-Time
LX Switch Off-Time
FB Input Current
LBI Input Current
CLSEL Input Current
SHDN Input Current
LBO
Low Output Voltage
I
SHDN
V
SHDN
=0 or V
OUT
L
LBI
=0, I
SINK
=1mA
V
LBO
=5.5V, L
LBI
=5.5V
-
-
-
-
-
0.8 V
OUT
-
0.8 V
OUT
0.07
0.2
0.07
88
-
-
-
-
50
0.4
1
150
0.2 V
OUT
-
0.2 V
OUT
-
nA
V
µA
Ω
V
V
I
LBO
LBO
Off Leakage Current
Damping Switch Resistance
AP1601, V
BATT
=2V
V
IL
V
IH
V
IL
V
IH
SHDN Input Voltage
CLSEL Input Voltage
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
V
IN
+
100uF
22uH
ON
OFF
SHDN
LX
OUT
+
R5
Adj Output (1.8V to 4.0V)
up to 300 mA
Low- Battery
Detect OUT
Low- Battery
Detect In
LBI
LBO
REF
0.1uF
GND
FB
220uF
R6
R5
)
R6
R6 Suggest 100K~200K
FB=Vout, Vout=3.3V
FB=GND, Vout=5V
Vout=1.2
×
(1+
Anachip Corp.
www.anachip.com.tw
4/9
Rev. 1.1 Apr. 14, 2005