FAN5307 — High-Efficiency Step-Down DC-DC Converter
August 2009
FAN5307
High-Efficiency Step-Down DC-DC Converter
Features
95% Efficiency, Synchronous Operation
Adjustable Output Voltage Option: 0.7V to 0.8V
IN
2.5V to 5.5V Input Voltage Range
Customized Fixed Output Voltage Options
Up to 300mA Output Current
Fixed Frequency 1MHz PWM Operation
High-Efficiency, Power-Save Mode
100% Duty Cycle Low Dropout Operation
Soft Start
Dynamic Output Voltage Positioning
15µA Quiescent Current
Excellent Load Transient Response
5-Lead SOT-23 Package
6-Lead MLP 3x3mm Package
Description
The FAN5307, a high-efficiency, low-noise synchronous
PWM current mode and Pulse Skip (Power-Save) mode
DC-DC converter, is designed for battery-powered
applications. It provides up to 300mA of output current
over a wide input range from 2.5V to 5.5V. The output
voltage can be either internally fixed or externally
adjustable over a wide range of 0.7V to 0.8V
IN
by an
external voltage divider. Custom output voltages are
also available. Contact a Fairchild sales representative
for customized output voltage options.
At moderate and light loads, pulse skipping modulation
is used. Dynamic voltage positioning is applied, and the
output voltage is shifted 0.8% above nominal value, for
increased headroom during load transients. At higher
loads, the system automatically switches to current
mode PWM control, operating at 1 MHz. A current
mode control loop with fast transient response ensures
excellent line and load regulation. In Power-Save mode,
the quiescent current is reduced to 15µA to achieve
high efficiency and ensure long battery life. In shutdown
mode, the supply current drops below 1µA.
The device is available in 5-lead SOT-23 and 6-lead
MLP 3x3mm packages.
Applications
Pocket PCs, PDAs
Cell Phones
Battery-Powered Portable Devices
Digital Cameras
Low Power DSP Supplies
Ordering Information
Part Number
FAN5307S18X
FAN5307MP18
X
FAN5307S15X
FAN5307MP15
X
FAN5307SX
FAN5307MPX
Operating
Temperature
Range
-40 to +85°C
-40 to +85°C
-40 to +85°C
-40 to +85°C
-40 to +85°C
-40 to +85°C
V
OUT
(V)
1.8
1.8
1.5
1.5
Adjustable
Adjustable
Package
5-Lead SOT-23
6-lead 3x3mm Molded
Leadless Package (MLP)
5-Lead SOT-23
6-lead 3x3mm Molded
Leadless Package (MLP)
5-Lead SOT-23
6-lead 3x3mm Molded
Leadless Package (MLP)
Eco
Status
RoHS
Green
RoHS
Green
RoHS
Green
Packing
Method
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
For Fairchild’s definition of Eco Status, please visit:
http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2005 Fairchild Semiconductor Corporation
FAN5307 • Rev. 1.0.5
www.fairchildsemi.com
FAN5307 — High-Efficiency Step-Down DC-DC Converter
Typical Applications
EN
GND
V
IN
C
IN
= 4.7µF
1
2
3
6
5
4
FB
PGND
V
OUT
L
X
10µH
C
OUT
=10µF
Figure 1. 6-Lead 3x3mm (MLP)
Figure 2. 5-Lead SOT-23
100
95
90
Efficiency [%]
V
IN
=2.5V
V
IN
=3.6V
V
IN
=5.5V
85
80
75
70
65
0.01
0.1
1
10
100
1000
Load Current [mA]
Figure 3. Efficiency vs. Load Current (V
OUT
=1.8V)
© 2005 Fairchild Semiconductor Corporation
FAN5307 • Rev. 1.0.5
www.fairchildsemi.com
2
FAN5307 — High-Efficiency Step-Down DC-DC Converter
Pin Configuration
Figure 4. 5-Lead SOT-23
Figure 5. 6-Lead 3x3mm MLP
Pin Definitions
5-Lead SOT-23
Pin #
1
2
3
4
5
Name
V
IN
GND
EN
FB
L
X
Description
Supply Voltage Input.
Ground.
Enable Input.
Logic HIGH enables the chip; logic LOW disables the chip and reduces supply
current to <1µA. Do not float this pin. If the EN pin is tied to V
IN
, V
IN
must be ramped up faster
than 5V/ms for V
OUT
to enter regulation.
Feedback Input.
In case of fixed-voltage options, connect this pin directly to the output. For an
adjustable voltage option, connect this pin to the resistor divider.
Inductor Pin.
This pin is connected to the internal MOSFET switches.
6-Lead 3x3mm MLP
Pin #
1
2
3
4
5
6
Name
EN
GND
V
IN
L
X
PGND
FB
Description
Enable Input.
Logic HIGH enables the chip; logic LOW disables the chip and reduces supply
current to <1μA. Do not float this pin. If the EN pin is tied to V
IN
, V
IN
must be ramped up faster
than 5V/ms for V
OUT
to enter regulation.
Reference Ground.
Supply Voltage Input.
Inductor Pin.
This pin is connected to the internal MOSFET switches
Power Ground.
The internal N-channel MOSFET is connected to this pin.
Feedback Input.
In case of fixed-voltage options, connect this pin directly to the output. For an
adjustable voltage option, connect this pin to the resistor divider.
© 2005 Fairchild Semiconductor Corporation
FAN5307 • Rev. 1.0.5
www.fairchildsemi.com
3
FAN5307 — High-Efficiency Step-Down DC-DC Converter
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device
reliability. The absolute maximum ratings are stress ratings only.
Symbol
V
IN
θ
JC
T
L
T
STG
ESD
(2)
Parameter
Supply Voltage
Input Voltage on PVIN and Any Other Pin
Thermal Resistance
(1)
Min.
-0.3
GND-0.2
Max.
6.5
V
IN
+0.3
130
8
+260
Unit
V
V
°C/W
°C
°C
kV
Junction-to-Case, SOT-23
Junction-to-Tab, MLP 3x3
-65
4
1
Lead Soldering Temperature, 10 Seconds
Storage Temperature
Human Body Model, JESD22-A114
Charged Device Model, JESD22-C101
+150
Notes:
1. Junction-to-ambient thermal resistance,
θ
JA
, is a strong function of PCB material, board thickness, thickness and
number of copper planes, number of via used, diameter of via used, available copper surface, and attached heat
sink characteristics.
2. Using Mil Std. 883E, method 3015.7 (Human Body Model) and EIA/JESD22C101-A (Charged Device Model).
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to Absolute Maximum Ratings.
Symbol
V
IN
V
OUT
I
OUT
L
C
IN
C
OUT
T
A
T
J
Parameter
Supply Voltage Range
Output Voltage Range, Adjustable Version
Output Current
Inductor
(3)
(3)
(3)
Min.
2.5
0.7
Typ.
Max.
5.5
0.8V
IN
300
Unit
V
V
mA
µH
µF
µF
10
4.7
10
-40
-40
+85
+125
Input Capacitor
Output Capacitor
Operating Ambient Temperature Range
Operating Junction Temperature Range
°C
°C
Note:
3. Refer to the
Applications
section for details.
© 2005 Fairchild Semiconductor Corporation
FAN5307 • Rev. 1.0.5
www.fairchildsemi.com
4
FAN5307 — High-Efficiency Step-Down DC-DC Converter
Electrical Characteristics
V
IN
=2.5V to 5.5V, I
OUT
=200mA, EN=V
IN
, C
IN
=4.7µF, C
OUT
=22µF, L
X
=10µH, T
A
=-40°C to +85°C, unless otherwise
noted. Typical values are at T
A
=25°C.
Symbol
V
IN
I
Q
I
SD
V
ENH
V
ENL
I
EN
Input Voltage
Parameter
Conditions
I
OUT
=0mA, Device is
not switching
EN=GND
Min.
2.5
Typ.
Max.
5.5
Units
V
µA
µA
V
V
µA
mΩ
mΩ
mA
µA
µA
kHz
%/V
% / mA
% / mA
Quiescent Current
Shutdown Supply Current
Enable High Input Voltage
Enable Low Input Voltage
En Input Bias Current
PMOS On Resistance
15
0.1
1.3
30
1.0
0.5
EN=V
IN
or GND
V
IN
=V
GS
=3.6V
V
IN
=V
GS
=2.5V
V
IN
=V
GS
=3.6V
V
IN
=V
GS
=2.5V
2.5V < V
IN
< 5.5V
V
DS
=5.5V
V
DS
=5.5V
800
V
IN
=2.5 to 5.5,
I
OUT
=10mA
400
0.01
530
670
430
530
520
0.1
0.1
1000
0.16
0.0014
0.0022
-4
-4
-5
0.1
0.1
0.10
690
850
540
660
700
1.0
1.0
1200
R
DS-ON
NMOS On Resistance
I
LIM
I
Ikg_(N
)
I
Ikg_(P)
P-channel Current Limit
N-channel Leakage Current
P-channel Leakage Current
Switching Frequency
R
LINE
Line Regulation
6-Lead MLP
5-Lead SOT-23
6-Lead MLP
V
OUT
Output Voltage
Accuracy
R
LOAD
Load
Regulation
100mA
≤
I
OUT
≤
300mA
100mA
≤
I
OUT
≤
300mA
V
IN
=2.5 to 5.5V,
0mA
≤
I
OUT
≤
300mA
V
IN
=2.5 to 4.5V,
0mA
≤
I
OUT
≤
300mA
V
IN
=2.5 to 5.5V,
0mA
≤
I
OUT
≤
300mA
V
IN
>V
OUT
,
0V
≤
V
SW
≤
V
IN
V
IN
=Open, EN=GND,
V
SW
=5.5
4
4
4
1.0
1.0
µA
µA
%
5-Lead SOT-23
I
LEAK
I
LEAK_R
Leakage Current into Pin SW
Reverse Leakage Current into Pin SW
Electrical Characteristics for Adjustable Version
V
IN
=2.5V to 5.5V, I
OUT
= 200mA, EN=V
IN
, C
IN
=4.7µF, C
OUT
=22µF, L
X
=10µH, T
A
=25°C.
Symbol
V
FB
Feedback Voltage
Parameter
Min.
Typ.
0.5
Max.
Units
V
© 2005 Fairchild Semiconductor Corporation
FAN5307 • Rev. 1.0.5
www.fairchildsemi.com
5