fa7612, Elektronika, , f
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FA7610CP(N)/12CP(N)/17CP(N)
Bipolar IC
For Switching Power Supply Control
FA7610CP(N)/FA7612CP(N)/FA7617CP(N)
n
Description
The FA7610CP(N), 7612CP(N) and 7617CP(N) are bipolar
ICs containing basic circuits necessary for PWM-type
switching power supply control.
To minimize the number of external discrete components, the
FA7610CP(N) is provided for a flyback or step-up power-
supply circuit, the FA7612CP(N) for a step-down power-supply
circuit and FA7617CP(N) for a flyback power supply circuit.
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Dimensions, mm
Á
SOP-8
8
5
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Features
FA7610CP(N)
• For flyback transformer-type or step-up power-supply circuit
(maximum output duty = 64% typical)
• Totem-pole predriver
• PWM-type switching power supply control
• Low-voltage operation (V
CC
= 3.6 to 22V)
• Latch-mode short-circuit protection function (no malfunction
by noise)
• Soft-start function
• Undervoltage lockout function
• One capacitor shared for short circuit protection and for soft-
start to minimize the number of external discrete components
1
4
4.9
0.4
±
0.1
1.27
±
0.2
Á
DIP-8
8
5
FA7612CP(N)
• For step-down power-supply circuit
(maximum output duty = up to 100%)
• Open collector output
• PWM-type switching power supply control
• Low-voltage operation (V
CC
= 3.6 to 22V)
• Latch-mode short-circuit protection function (no malfunction
by noise)
• Soft-start function
• Undervoltage lockout function
• One capacitor shared for short circuit protection and for soft-
start to minimize the number of external discrete components
4
1
9.3
1.5
7.6
2.54
±
0.25
0.5
±
0.1
FA7617CP(N)
• For flyback transformer-type power-supply circuit (maximum
output duty = 67% typical)
• Open collector output
• PWM-type switching power supply control
• Low-voltage operation (V
CC
= 3.6 to 22V)
• Latch-mode short-circuit protection function (no malfunction
by noise)
• Soft-start function
• Undervoltage lockout function
• One capacitor shared for short circuit protection and for soft-
start to minimize the number of external discrete components
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Applications
• Battery power supply for portable equipment
1
FA7610CP(N)/FA7612CP(N)/FA7617CP(N)
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Block diagram
Á
FA7610CP(N)
Pin
Pin
Description
No.
symbol
IN (–)
1
Inverting input to error amplifier
FB
2
Error amplifier output
GND
3
Ground
OUT
4
Output
VCC
5
Power supply
CS
6
Capacitor for soft-start, short-circuit protection and delay
CT
7
Oscillator timing capacitor
REF
8
Reference voltage output (2.5V)
Á
FA7612CP(N)
Pin
Pin
Description
No.
symbol
IN (–)
1
Inverting input to error amplifier
FB
2
Error amplifier output
GND
3
Ground
OUT
4
Output
VCC
5
Power supply
CS
6
Capacitor for soft-start, short-circuit protection and delay
CT
7
Oscillator timing capacitor
REF
8
Reference voltage output (2.5V)
Á
FA7617CP(N)
Pin
Pin
Description
No.
symbol
IN (–)
1
Inverting input to error amplifier
FB
2
Error amplifier output
GND
3
Ground
OUT
4
Output
VCC
5
Power supply
CS
6
Capacitor for soft-start, short-circuit protection and delay
CT
7
Oscillator timing capacitor
REF
8
Reference voltage output (2.5V)
2
FA7610CP(N)/FA7612CP(N)/FA7617CP(N)
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Absolute maximum ratings
(Ta = 25
°
C)
Item
Symbol
Rating
Unit
FA7610C
FA7612C/17C
V
CC
Supply voltage
22
22
V
I
OR
Reference voltage output current
5
5
mA
I
O
Output current
±
50
80
mA
P
d
Total power dissipation
400
400
mW
T
opr
Operating temperature
–20 to +85
–20 to +85
°
C
T
stg
Storage temperature
–40 to +150
–40 to +150
°
C
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Recommended operating conditions
Item
Symbol
FA7610C
FA7612/17C
Unit
Min.
Max.
Min.
Max.
V
CC
Supply voltage
3.6
20
3.6
20
V
R
NF
Feedback resistance
100
100
k
W
C
T
Oscillator timing capacitor
220
22,000
220
22,000
pF
R
T
Oscillator timing resistance
10
100
10
100
k
W
f
OSC
Oscillation frequency
5
200
5
500
kHz
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Electrical characteristics
(Ta = 25
°
C, V
CC
= 6V, R
T
= 33k
W
, C
T
= 1000pF)
Reference voltage section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
V
REF
I
OR
= 1mA
Output voltage
2.528
2.580
2.632
V
L
INE
V
CC
= 3.6 to 20V,
I
OR
= 1mA
Line regulation
4
12
mV
L
OAD
I
OR
= 0.1 to 1mA
Load regulation
1
6
mV
V
TC1
Output voltage variation due to temperature change
Ta = –20 to +25
°
C
–1
1
%
V
TC2
Ta = +25 to +85
°
C
–1
1
%
Oscillator section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
f
OSC
C
T
= 1000pF,
R
T
= 33k
W
Oscillation frequency
100
111
122
kHz
f
dV
V
CC
= 3.6 to 20V
Frequency variation 1 (due to supply voltage change)
1
%
f
dT
Frequency variation 2 (due to temperature change)
Ta = –20 to +85
°
C
5
%
Error amplifier section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
V
B
Reference voltage
0.515
0.525
0.535
V
I
B
Input bias current
5
100
nA
A
V
Open-loop voltage gain
70
dB
G
B
Unity-gain bandwidth
0.6
MHz
V
OM+
R
NF
= 100k
W
V
REF
–0.2
Maximam output voltage (Pin 2)
V
V
OM–
R
NF
= 100k
W
200
mV
I
OM+
V
OM
= 1V
Output source current (Pin 2)
40
85
200
m
A
PWM comparator section
Item
Symbol Test condition
FA7610C
FA7612C
FA7617C
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
Min.
Typ.
Max.
V
TH0
Input threshold voltage (pin 2)
Duty cycle = 0%
0.85
0.95
0.85
0.95
0.85
0.95
V
V
TH50
Input threshold voltage (pin 2)
Duty cycle = 50%
1.1
1.1
1.1
V
Maximum duty cycle
a
M
(Pin 2 = 1.2V)
58
64
75
100
63
67
71
%
3
FA7610CP(N)/FA7612CP(N)/FA7617CP(N)
Soft-start circuit section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
I
BCS
Input bias current (Pin 6)
80
300
nA
V
TH CS0
Input threshold voltage (Pin 6)
Duty cycle = 0%
0.22
0.32
V
V
TH CS50
Input threshold voltage (Pin 6)
Duty cycle = 50%
0.46
V
Short-circuit protection circuit section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
V
TH PC
Input threshold voltage (Pin 2)
1.20
1.50
1.80
V
I
CHG
Charge current (Pin 6)
Pin 6 = 0V, Pin 2 = 2V
20
30
40
m
A
V
TH LA
Latch-mode threshold voltage (Pin 6)
1.20
1.50
1.80
V
Undervoltage lockout circuit section
Common to FA7610C/12C/17C
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
V
TH ON
OFF-to-ON threshold voltage
2.70
V
V
TH OFF
ON-to-OFF threshold voltage
2.52
V
V
HYS
Voltage hysteresis
60
180
mV
Output section
Item
Symbol
Test condition
FA7610C
FA7612C/17C
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
V
OH
R
L
= 10k
W
H-level output voltage (Pin 4)
.5 .0
———V
V
OL
L-level output voltage (Pin 4)
Output sink
0.25
0.65
0.9
1.5
V
current = 20mA
I
SOURCE
Output source current (Pin 4)
Pin 4 = 0V
8
11
14
——— A
Overall device
Item
Symbol
Test condition
FA7610C
FA7612C/17C
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
I
CC LA
Supply current
Latch mode
1.6
2.2
1.5
2.2
mA
I
CC AV
R
L
=
¥
Operating-state supply current
2.6
3.8
1.8
3.0
mA
Duty cycle = 50%
4
FA7610CP(N)/FA7612CP(N)/FA7617CP(N)
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Characteristic curves
(Ta = 25
°
C)
Oscillation frequency(f
OSC
) vs.
Output duty cycle vs. CS terminal voltage(V
CS
)
timing capacitor capacitance(C
T
)
Output source current (I
source
) vs.
L-level output voltage(V
OL
) vs. output sink current
supply voltage(V
CC
)
(I
SINK
)
Supply current(I
CC
) vs. supply voltage(V
CC
)
Error amplifier frequency(f) vs. voltage gain(AV) / phase (
q
)
5
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