2004 Fairchild Semiconductor Corporation
1
www.fairchildsemi.com
October 2004
FAN5331 Rev. 1.0.1
F
AN53
3
1 1.6MHz Bo
ost Co
nverter
with
20V Integrated
FET Switch
FAN5331
1.6MHz Boost Converter with 20V Integrated FET Switch
Features
1.6MHz Switching Frequency
Low Noise
Low R
DS(ON)
: 0.5
Adjustable Output Voltage
1A Peak Switch Current
Low Shutdown Current: <1A
Cycle-by-Cycle Current Limit
Over-Voltage Protection
Fixed -Frequency PWM Operation
Internal Compensation
5-lead SOT-23 Package
Applications
Cell Phones
PDAs
Handheld Equipment
Display Bias
LED Bias
Description
The FAN5331 is a general purpose, fixed-frequency boost con-
verter designed to operate at high switching frequencies in
order to minimize switching noise measured at the battery ter-
minal of hand-held communications equipment. Quiescent cur-
rent in normal mode of operation as well as in shutdown mode
is designed to be minimal in order to extend battery life. Normal
mode of operation or shutdown mode can be selected by a logic
level shutdown circuitry.
The low ON-resistance of the internal N-channel switch ensures
high efficiency and low power dissipation. A cycle-by-cycle cur-
rent limit circuit keeps the peak current of the switch below a
maximum value of 1A. The FAN5331 is available in a 5-lead
SOT-23 package.
Typical Application
Figure 1. Typical Application Diagram
SHDN
V
IN
V
OUT
R1
R2
GND
V
IN
FB
SW
F
AN5331
C
F
C
IN
10
H
1
3
2
4
5
4.7
F
120pF
C
OUT
L
BAT54
4.7
F
2.7V to 5.5V
ON
OFF
2
www.fairchildsemi.com
FAN5331 Rev. 1.0.1
F
AN53
3
1 1.6MHz Bo
ost Co
nverter
with
20V Integrated
FET Switch
Pin Assignment
Figure 2. Pin Assignment
Pin Description
Absolute Maximum Ratings (
Note1)
Recommended Operating Conditions
Notes:
1. Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This
is a stress rating only and functional operation of the device at these or any other conditions above those indicated
in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability. Absolute maximum ratings apply individually only, not in combination.
2. Using EIA/JESD22A114B (Human Body Model) and EIA/JESD22C101-A (Charge Device Model).
3. This load capacitance value is required for the loop stability. Tolerance, temperature variation, and voltage
dependency of the capacitance must be considered. Typically a 4.7F ceramic capacitor is required to achieve
specified value at V
OUT
= 15V.
Pin No.
Pin Name
Pin Description
1
SW
Switching node.
2
GND
Analog and power ground.
3
FB
Feedback node that connects to an external voltage divider.
4
SHDN
Shutdown control pin. Logic HIGH enables, logic LOW disables the device.
5
V
IN
Input voltage.
Parameter
Min
Max
Unit
V
IN
to GND
6.0
V
FB, SHDN to GND
-0.3
V
IN
+ 0.3
V
SW to GND
-0.3
23
V
Lead Soldering Temperature (10 seconds)
300
C
Junction Temperature
150
C
Storage Temperature
-55
150
C
Thermal Resistance (
JA
)
265
C/W
Electrostatic Discharge Protection (ESD) Level (Note 2)
HBM
2.5
kV
CDM
1
Parameter
Min
Typ
Max
Unit
Input Voltage
2.7
5.5
V
Output Voltage
V
IN
20
V
Operating Ambient Temperature
-40
25
85
C
Output Capacitance (Note 3)
1.6
F
SW
GND
FB
SHDN
V
IN
5-Lead SOT-23
Top View
3
www.fairchildsemi.com
FAN5331 Rev. 1.0.1
F
AN53
31 1.6MHz Bo
ost Co
nverter
with
20V Integrated
FET Switch
Electrical Characteristics
Test Circuit
Figure 3. Test Circuit
Unless otherwise noted, V
IN
= 3.6V, T
A
= -40C to +85C, Typical values are at T
A
= 25C, Test Circuit,
Figure 3.
Parameter
Conditions
Min.
Typ.
Max.
Units
Switch Current Limit
V
IN
= 3.2V 0.7 1
A
Load Current
V
OUT
= 15V,
35
mA
V
OUT
= 15V,
50
mA
Switch On-resistance
V
IN
= 5V
0.5
V
IN
= 3.6V
0.7
Quiescent Current
V
SHDN
= 3.6V, No Switching
0.7
mA
V
SHDN
= 3.6V, Switching
1.6
3.0
mA
OFF Mode Current
V
SHDN
= 0V
0.1
2
A
Shutdown Threshold
Device ON
1.5
V
Device OFF
0.5
V
Shutdown Pin Bias Current
V
SHDN
= 0V or V
SHDN
= 5.5V
10
nA
Feedback Voltage
I
Load
= 0mA
1.205
1.230
1.255
V
Feedback Pin Bias Current
10
nA
Feedback Voltage Line Regulation
2.7V < V
IN
< 5.5V, I
LOAD
= 0mA
0.6
1.2
%
Switching Frequency
1.15
1.6
1.85
MHz
Maximum Duty Cycle
87
93
%
Enable Delay
V
IN
= 2.7V, I
OUT
= 35mA, V
OUT
= 15V
0.8
5
mS
Power on Delay
V
IN
= 2.7V, I
OUT
= 35mA, V
OUT
= 15V
0.8
5
mS
Switch Leakage Current
No Switching, V
IN
= 5.5V
1
A
V
IN
2.7V
V
IN
3.2V
150K
13.4K
SHDN
V
IN
V
OUT
R1
R2
GND
V
IN
FB
SW
F
AN
5331
C
F
C
IN
10
H
1
3
2
4
5
4.7
F
120pF
C
OUT
L
BAT54
4.7
F
2.7V to 5.5V
ON
OFF
4
www.fairchildsemi.com
FAN5331 Rev. 1.0.1
F
AN53
3
1 1.6MHz Bo
ost Co
nverter
with
20V Integrated
FET Switch
Typical Performance Characteristics
T
A
= 25C, Test Circuit Figure 3, unless otherwise noted.
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0
50
100
150
200
250
300
350
Maximum Load Current vs Input Voltage
M
a
x
i
m
u
m
Loa
d C
u
rren
t
(m
A)
Input Voltage (V)
V
O
UT
=
1
2V
V
O
UT
=
15
V
V
OU
T
=
21V
-50
0
50
100
150
1.21
1.22
1.23
1.24
1.25
Temperature (C) vs Vf (Vin=2.7V, Iload=15mA)
Temperature (C) vs Vf (Vin=3.6V, Iload=15mA)
Temperature (C) vs Vf (Vin=5.5V, Iload=15mA)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
14.86
14.88
14.90
14.92
14.94
14.96
14.98
VIN(V) vs VOUT(V) at Iload=0mA
VIN(V) vs VOUT(V), at load=10mA
VIN(V) vs VOUT(V), at load=20mA
VIN(V) vs VOUT(V) at Iload=30mA
VIN(V) vs VOUT(V) at Iload=40mA
VIN(V) vs VOUT(V) at Iload=50mA
Output Voltage vs Input Voltage
Outp
ut V
o
lt
age
(V)
Input Voltage (V)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0.72
0.74
0.76
0.78
0.80
0.82
0.84
0.86
0.88
0.90
0.92
VIN(V) vs Efficiency at Iload =10mA
VIN(V) vs Efficiency at Iload =20mA
VIN(V) vs Efficiency at Iload =30mA
VIN(V) vs Efficiency at Iload =40mA
VIN(V) vs Efficiency at Iload =50mA
Effic
i
en
cy
Input Voltage (V)
Efficiency vs Input Voltage
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Supply Current vs Input Voltage
Su
pp
ly C
u
rren
t
(m
A)
Input Voltage (V)
Switching
Non Switching
-40
-20
0
20
40
60
80
100
120
140
1.0
1.2
1.4
1.6
1.8
Swi
t
ch
ing Freq
ue
ncy
(M
Hz)
Ambient Temperature (C)
Switching Frequency vs Ambient Temperature
I
OUT
= 15mA
V
OUT
= 15V
V
IN
= 3.6V
Feedback Voltage vs Ambient Temperature
I
OUT
= 15mA
Ambient Temperature (C)
Fe
ed
ba
ck
V
o
lt
age
(V)
I
OUT
= 0mA
5
www.fairchildsemi.com
FAN5331 Rev. 1.0.1
F
AN53
3
1 1.6MHz Bo
ost Co
nverter
with
20V Integrated
FET Switch
Typical Performance Characteristics
(Contd.)
T
A
= 25C, Test Circuit Figure 3, unless otherwise noted.
Output Power Spectral Density
V
IN
= 3.6V
I
OUT
= 35mA
Time (20
s/div)
(5
V
/
di
v
)
Startup After Enable
Time (200
s/div)
R
L
= 300
V
IN
= 3V
(2
00m
A/d
i
v)
V
OUT
= 15V
Inductor Current= 0mA
Line Transient Response
Time (100
s/div)
Outp
ut V
o
l
t
a
g
e
I
npu
t V
o
lt
ag
e
-0.6V
+
0.6V
V
IN
= 4.2V
V
IN
= 3.2V
Load Transient Response
I
OUT
= 30mA
T
r
= T
f
= 10S
V
OUT
= 15V
(10
m
A/D
i
v)
(1
00
mV
/Div
)
V
OUT
= 15V
I
OUT
= 0 to 35mA
T
r
= T
r
= <1
S
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