FA551X
1
Block diagram
FA5510P (N), FA5511P (N)
FA5514P (N), FA5515P (N)
FA551X series
Dimensions, mm
SOP-8
FA5510P (N), FA5511P (N)
FA5514P (N), FA5515P (N)
Description
The FA551X series are the PWM type switching power supply
control ICs that can directly drive power MOSFET. These ICs
use a CMOS device with high dielectric strength (30V) to
implement low power consumption. These ICs contain many
function in a small 8-pin package. With these ICs, a high-
performance and compact power supply can be created
because not many external discrete components are needed.
Features
Low current consumption by CMOS process with high
dielectric strength (30V)
Standby current of 2A or less (at Vcc=14V), and operating
current of 1.5mA (typ)
Overvoltage protection function detecting the Vcc voltage
A drive circuit for connecting a power MOSFET directly
Output peak current: 1.5A
Pulse-by-pulse overcurrent limiting function
Overload protection function (latch or non-latch mode selectable)
Output ON-OFF function by external signal
Latch-mode overvoltage shutdown function
Undervoltage lockout function (16.5V ON / 9V OFF)
Reference voltage output (5V)
8-pin package (DIP/SOP)
CMOS IC
For Switching Power Supply Control
4.9
3.9
6.0
0.2
0.4
0.1
1.27
0.20
+0.1
0.05
0~8
1
4
8
5
1.8max
DIP-8
1
8
5
4
9.3
6.4
7.62
3.3
4.5max
1.5
0.3
3.0min
0~15
0~15
0.46
0.1
2.54
0.25
+0.1
0.05
Type
Max. duty
Polarity of overcurrent Package
cycle (typ.)
detection
FA5510P
46%
+
DIP-8
FA5510N
SOP-8
FA5511P
70%
+
DIP-8
FA5511N
SOP-8
FA5514P
46%
DIP-8
FA5514N
SOP-8
FA5515P
70%
DIP-8
FA5515N
SOP-8
0.8V/0.68V
8.5V/7.9V
5V VCC
ENB
5V REF
3.5V
4V
RT CT
OSC
+0.24V
R
S
QB
Q
ENB
OUT
PUT
16.5V/9V
UVLO
15.5V
15.5V
5.2
A
0.95mA
PWM
0.8V
Dmax
FA5510: 46%
FA5511: 70%
5V Controlled block
FB
(2)
REF
(7)
CS(8)
VCC(6)
OUT
(5)
GND
(4)
IS+(3)
RT(1)
FF
0.8V/0.68V
8.5V/7.9V
5V VCC
ENB
5V REF
3.5V
4V
RT CT
OSC
-0.17V
R
S
QB
Q
ENB
OUT
PUT
16.5V/9V
UVLO
15.5V
15.5V
5.2
A
0.95mA
PWM
0.8V
Dmax
FA5514: 46%
FA5515: 70%
5V Controlled block
FB
(2)
REF
(7)
CS(8)
VCC(6)
OUT
(5)
GND
(4)
IS-(3)
RT(1)
FF
Pin Pin
Function
Description
No. symbol
1
RT
Oscillator timing
Setting oscillation frequency
resistor
2
FB
Feedback
Input of PWM comparator
3
IS
Overcurrent
Input of the overcurrent
detection
limiting function
4
GND
Ground
Ground
5
OUT
Output
Output for driving a power
MOSFET
6
VCC
Power supply
Power supply
7
REF
Reference voltage
Reference voltage output (5V)
8
CS
Soft-start and
Soft-start, ON/OFF function and
ON/OFF control
latch-mode shutdown operations
FA551X
2
Maximum power dissipation curve
Absolute maximum ratings
I
tem
Symbol
Rating
Unit
Supply Voltage
Low impedance source (I
CC
>15mA)
V
CC1
30
V
Internal zener clamp (I
CC
<15mA)
V
CC2
Self limiting
V
Output peak current
I
OUT
1.5
A
FB pin input voltage
V
FB
0.3 to 5.0
V
IS pin input voltage
V
IS
0.3 to 5.0
V
REF pin source current
I
REF
10
mA
CS pin sink current
I
CS
+2.0
mA
Total power dissipation (Ta=25C)
Pd
800 (DIP-8)
mW
400 (SOP-8)
Ambient temperature
Ta
30 to +85
C
Maximum junction temperature
Tj
125
C
Storage temperature
Tstg
40 to +150
C
Note: There are cases where the IC cannot output the rating current depending on Vcc voltage or temperature.
30
25
85
125
0
Ambient temperature Ta [C]
Max.
po
w
er
dissipation
400mW (SOP)
800mW (DIP)
Recommended operating conditions
Item
Symbol
Min.
Typ.
Max.
Unit
Supply voltage
V
CC
10
28
V
Oscillation frequency
f
OSC
10
500
kHz
REF-GND capacitor
Cref
0.1
0.47
F
Soft start capacitor
C
S
0.01
1
F
FA551X
3
Electrical characteristics (V
CC
=18V, R
T
=47k
, Ta=25C)
Reference voltage section (REF pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Reference voltage
V
REF
Tj=25C
4.75
5.00
5.25
V
Line regulation
V
dv1
V
CC
=10 to 28V
6
20
mV
Load regulation
V
dv2
I
L
=0 to 10mA, V
CC
=18V
40
12
mV
Temperature stability
V
dT
Ta=30 to 85C
0.5
mV/C
Oscillator section (RT pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Oscillation frequency
f
OSC
R
T
=47k
, Tj=25C
92.6
100
107.4
kHz
Voltage stability
f
dv
V
CC
=10 to 28V
1.0
%
Temperature stability
f
dT
Ta=30 to 85C
0.02
%/C
Pulse width modulation circuit section (FB pin)
Item
Symbol
Test condition
FA5510/14
FA5511/15
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
FB pin source current
I
FB
V
FB
=0
855
720
585
855
720
585
A
Input threshold voltage (FB pin)
V
TH FB0
Duty cycle =0%
0.9
1
0.9
1
V
V
TH FBM
Duty cycle =
D
MAX
1.92
2.40
V
Maximum duty cycle
D
MAX
42
46
50
66
70
74
%
Overcurrent limiting circuit section (IS pin)
Item
Symbol
Test condition
FA5510/11
FA5514/15
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
Input threshold voltage (IS pin)
V
THIS
220
240
260
190
170
150
mV
Source current (IS pin)
I
IS
V
IS
=0V
5
28
20
12
A
Delay time
t
pdIS
150
150
ns
Output ON/OFF control circuit section (CS pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Source current (CS pin)
I
S0CS
V
CS
=0V, Tj=25C
7.2
5.2
3.2
A
ON/OFF control threshold voltage (CS pin)
V
THON
OFF
ON, Tj=25C
0.8
0.93
V
V
THOFF
ON
OFF, Tj=25C
0.50
0.68
V
Hysteresis voltage
V
THOHS
0.12
V
Soft start circuit section (CS pin)
Item
Symbol
Test condition
FA5310/14
FA5311/15
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
Charge current (CS pin)
I
CHG
V
CS
=1V, Tj=25C 7.2
5.2
3.2
7.2
5.2
3.2
A
Input threshold voltage (CS pin)
V
TH CS0
Duty cycle =0%
0.90
1.0
0.90
1.0
V
V
TH CSM
Duty cycle =
D
MAX
1.92
2.40
V
FA551X
4
Overload cutoff circuit section (FB pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Overload threshold voltage (FB pin)
V
TH FB
3.2
3.5
3.8
V
Overvoltage cutoff circuit section (VCC pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Overvoltage threshold voltage (VCC pin)
V
TH VCC
Tj=25C
30
31.8
34
V
Cutoff operating supply current (VCC pin)
I
VCC
Tj=25C, V
CC
=V
THVCC
14
mA
Charge current (CS pin)
I
S0CS2
V
CS
=6.5V
1.4
0.95
0.5
mA
Undervoltage lockout circuit section (VCC pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
OFF-to-ON threshold voltage
V
CC ON
Tj=25C
15.5
16.5
17.5
V
ON-to-OFF threshold voltage
V
CC OFF
Tj=25C
8.5
9.0
10.0
V
Hysteresis voltage
V
HYS
Tj=25C
6.8
7.5
8.2
V
Output circuit section (OUT pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Low output voltage
V
OL
I
OL
=100mA
0.7
1.5
V
High output voltage
V
OH
I
OH
=100mA, V
CC
=18V
15
16.5
V
Rise time
tr
C
L
=1nF
40
ns
Fall time
tf
C
L
=1nF
25
ns
Latch-mode cutoff circuit section (CS pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Sink current (CS pin)
I
SICS
V
CS
=6.5V, V
FB
=1V, Tj=25C
18
30
45
A
Cutoff threshold voltage (CS pin)
V
TH CSF
ON
OFF, Tj=25C
8.0
8.5
9.0
V
V
TH CSN
OFF
ON, Tj=25C
7.4
7.9
8.4
V
Hysteresis voltage
V
THHIS
0.6
V
Supply current (VCC pin)
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Stand-by current
I
CCSTB
V
CC
=14V
2
A
Startup current
I
CCST
V
CC
=OFF-to-ON threshold voltage
12
30
A
Operating-state supply current
I
CCOP
No load
1.5
2.5
mA
OFF-state supply current
I
CCOF
V
CC
=17V, CS=0V
80
200
A
Latch mode supply current
I
CCL
V
CC
=10V
45
80
A
FA551X
5
Characteristic curves (V
CC
=18V, R
T
=47k
, Ta=25C)
Oscillation frequency (f
OSC
) vs.
Oscillation frequency (f
OSC
) vs. supply voltage (V
CC
)
timing resistor resistance (R
T
)
Oscillation frequency (f
OSC
) vs.
FB pin source current (I
FB
) vs. FB pin voltage (V
FB
)
junction temperature (Tj)
Maximum duty cycle (D
MAX
) vs. timing resitor resistance (R
T
)
Maximum duty cycle (D
MAX
) vs. timing resitor resistance (R
T
)
FA5510/14
FA5511/15
1
10
100
1000
1
10
100
1000
R
T
(k
)
fosc (kHz)
99.9
99.92
99.94
99.96
99.98
100
100.02
100.04
100.06
100.08
100.1
10
15
20
25
30
Vcc (V)
fosc (kHz)
98.5
99
99.5
100
100.5
101
101.5
102
50
0
50
100
150
Tj (C)
fosc (kHz)
-800
-700
-600
-500
-400
-300
-200
-100
0
0
1
2
3
4
5
V
FB
(V)
I
FB
(
A)
42
43
44
45
46
47
48
49
1
10
100
1000
R
T
(k
)
D
MAX
(%)
67
68
69
70
71
72
1
10
100
1000
R
T
(k
)
D
MAX
(%)
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