FA7700V, FA7701V
s
Description
FA7700V/FA7701V are the PWM type DC to DC converter
control ICs with 1ch output that can directly drive power
MOSFETs. CMOS devices with high breakdown voltage are
used in these ICs and low power consumption is achieved.
These ICs have not only the functions equivalent to those of
FA76XX series but also the functions of directly driving Nch/Pch
MOSFETs, lower power consumption, higher frequency
operation, and less external components.
CMOS IC
For Switching Power Supply Control
FA7700V, FA7701V
s
Dimensions, mm
TSSOP-8
4.4
±0.2
6.4
±0.3
s
Features
• Wide range of supply voltage: V
CC
=2.5 to 20V
• FA7700V: For boost, flyback converter
(Maximum output duty cycle is 80%)
• FA7701V: For buck converter
(Maximum output duty cycle is 100%)
• Output stage consist of CMOS push-pull circuit, and achieves
a high speed switching of external MOSFETs. (FA7700V: For
Nch-MOSFET driving, FA7701V: For Pch-MOSFET driving)
• High accuracy reference voltage (Error amplifier): 0.88V±2%
• Soft start function
• Adjustable built-in timer latch for short-circuit protection
• Output ON/OFF control function
• Less external discrete components needed (2 components
less than conventional version of the equivalent products)
• Low power consumption
Stand-by current: 40µA typ.
Operating current: 1.2mA typ. (Including error amplifier output
current and oscillator current)
• High frequency operation: 50kHz to 1MHz
• Package: TSSOP-8, thin and small
0.575 typ
1.30 max
3.1
±0.3
0.1
±0.05
10 to 0
˚
0.65
0.22
±0.1
0.5
±0.2
s
Block diagram
FA7700V
FA7701V
RT
1
VREF
UVLO
8
0.3V
ON/OFF
0.15
±0.1
CS
RT
1
VREF
UVLO
8
0.3V
ON/OFF
CS
REF
2
3
4
VREF
2.2V
–
+
OSC
5.5V
1.5V
S.C.P
BIAS
1.5V
Power Good Signal
S.C.DET
+
–
2.2V
7
6
5
VCC
REF
2
3
4
VREF
2.2V
–
+
OSC
S.C.P
1.5V
S.C.DET
1.5V
BIAS
Power Good Signal
+
–
2.2V
5.5V
7
6
5
VCC
IN–
+
–
ON/OFF
OFF
0.88V
+
–
ER.AMP
+
–
+
+
OUT
IN–
+
–
ON/OFF
OFF
0.88V
+
–
+
–
+
OUT
PWM
PWM
ER.AMP
FB
GND
FB
GND
Pin No. Pin symbol Description
1
2
3
4
5
6
7
8
RT
REF
IN (–)
FB
GND
OUT
VCC
CS
Oscillator timing resistor
Internal bias voltage
Error amplifier inverting input
Error amplifier output
Ground
Output for driving switching device
Power supply
ON/OFF, soft start, timer latched short
circuit protection
1
FA7700V, FA7701V
s
Absolute maximum ratings
I
tem
Power supply voltage
REF terminal output current
OUT terminal source current
OUT terminal sink current
RT, REF, IN–, FB terminal voltage
CS terminal voltage
CS terminal sink current
Power dissipation
Operating ambient temperature
Operating junction temperature
Storage temperature
Symbol
Vcc
I
REF
I
SO peak
I
SO cont
I
SI peak
I
SI cont
V
RT
, V
REF
V
IN–
, V
FB
V
CS
I
CS
Pd
Ta
Tj
T
stg
Rating
20
2
–400 (peak)
–50 (continuos)
+150 (peak)
+50 (continuos)
+2.5 (max.)
–0.3 (min.)
Self limiting 5.5 (max.)
–0.3 (min.)
200
250 (Ta 25˚C)
–30 to +85
+125
–40 to +150
Unit
V
mA
mA
mA
V
V
µA
mW
˚C
˚C
˚C
Maximum power dissipation curve
300
Max. power
dissipation [mW]
250
200
150
100
50
0
–30
0
30
60
90
125
150
Ambient temperature [˚C]
s
Recommended operating condition
Item
Supply voltage
DC feedback resistor of error amplifier
VCC terminal capacitance
REF terminal capacitance
CS terminal capacitance
CS terminal sink current
Oscillation frequency
Symbol
V
CC
R
NF
C
VCC
C
REF
C
S
I
csin
f
osc
Min.
2.5
100
0.1
0.047
0.01
1*
50
V
CC
– 1.5
50µA + I
L
R
CS
[MΩ]
V
CC
– 1.5
1µA + I
L
Typ.
6
Max.
18
Unit
V
kΩ
µF
0.1
1
10
50
1000
µF
µF
µA
kHz
* Lower limit of I
CSIN
does not include leak current “I
L
” for capacitor Cs. Set a
resistor “R
CS
[MΩ]” connected between VCC terminal and CS terminal to
satisfy the equation.
2
FA7700V, FA7701V
s
Electrical characteristics
(Ta=25˚C, V
CC
=6V, R
T
=22kΩ)
Internal bias section (REF terminal voltage)
Item
Output voltage
Line regulation
Load regulation
Variation with temperature
Symbol
V
REF
V
LINE
V
LOAD
V
TC1
V
TC2
Test condition
REF terminal source current
I
REF
=0mA
Vcc=2.5 to 20V, I
REF
=0mA
I
REF
=0 to 2mA
Ta=–30 to 25°C
Ta=25 to 85°C
±2
±2
±0.3
±0.3
±14
±12
mV
mV
%
%
Min.
2.16
Typ.
2.23
Max.
2.30
Unit
V
Oscillator section (Frequency set by R
T
terminal)
Item
Oscillation frequency
Line regulation
Variation with temperature
Symbol
f
osc
f
LINE
f
TC1
f
TC2
Test condition
R
T
=22kΩ
Vcc=2.5 to 20V
Ta=–30 to 25°C, 50k to 1MHz
Ta=25 to 85°C, 50k to 1MHz
Min.
155
Typ.
185
±0.1
±2
±3
Max.
215
Unit
kHz
%
%
%
Error amplifier section (IN- terminal, FB terminal)
Item
Reference voltage
Input current
V
B
line regulation
V
B
variation with temperature
Open loop gain
Unity gain bandwidth
Output current
Source
Sink
Symbol
V
B
I
IN–
V
BLINE
V
BTC1
V
BTC2
A
VO
f
T
I
OHE
I
OLE
FB terminal=V
REF
– 0.5V
FB terminal=0.5V
–220
3
Vcc=2.5 to 20V
Ta=–30 to 25°C
Ta=25 to 85°C
70
1.5
–160
6
–100
12
Test condition
IN- terminal, FB terminal:
Shorted (voltage follower)
-500
±1
±0.3
±0.3
+500
±5
nA
mV
%
%
dB
MHz
µA
mA
Min.
0.863
Typ.
0.880
Max.
0.897
Unit
V
Pulse width modulation (PWM) section (FB terminal voltage and duty cycle)
Item
FB 0% threshold
FB 50% threshold
Maximum duty cycle
FA7700
Symbol
V
FB0
V
FB50
D
MAX1
D
MAX2
D
MAX3
FA7701
D
MAX
Test condition
Duty cycle = 0%
Duty cycle = 50%
R
T
=100kΩ, f=50kHz
R
T
=22kΩ, f 185kHz
R
T
=3kΩ, f 1MHz
85
83
80
100
Min.
0.560
Typ.
0.660
0.880
90
88
86
95
93
92
Max.
0.760
Unit
V
V
%
%
%
%
Undervoltage lock-out section (V
CC
terminal voltage)
Item
ON threshold
OFF threshold
Hysteresis voltage
Variation with temperature
Symbol
V
CCON
V
CCOF
V
CCHY
V
CCHY
Ta= –30 to 25°C
Ta= 25 to 85°C
1.60
0.04
Test condition
Min.
Typ.
2.07
1.93
0.14
+0.2
–0.2
0.24
Max.
2.30
Unit
V
V
V
mV/°C
mV/°C
3
FA7700V, FA7701V
ON/OFF section (CS terminal voltage)
Item
ON/OFF threshold
Threshold variation with temperature
Symbol
V
ONOF
V
ONTC
Ta = –30 to 85°C
Test condition
Min.
0.150
Typ.
0.300
+0.5
Max.
0.450
Unit
V
mV/°C
Soft start section (CS terminal voltage)
Item
Threshold voltage 1
Threshold voltage 2
Symbol
V
CS0
V
CS50
Test condition
Duty cycle=0%
Duty cycle=50%
Min.
0.560
Typ.
0.660
0.880
Max.
0.760
Unit
V
V
Timer latched short circuit protection section (FB terminal, CS terminal)
Item
Short detection threshold voltage
Latched mode threshold voltage
Latched mode reset voltage
Latched mode hysteresis
CS terminal clamped voltage
Symbol
V
FBTH
V
CSTH
V
CSRE
V
CSHY
V
CSCL1
V
CSCL2
Test condition
FB terminal voltage
CS terminal voltage
CS terminal voltage
CS terminal voltage
FB terminal<1.35V, CS sink current= +1µA
FB terminal>1.65V, CS sink current= +150µA
Min.
1.350
2.050
1.700
50
1.400
4.500
Typ.
1.500
2.200
2.030
170
1.500
5.500
Max.
1.650
2.350
2.300
350
1.600
6.500
Unit
V
V
V
mV
V
V
Output stage section (OUT terminal)
Item
High side on resistance
Low side on resistance
Rise time
Fall time
FA7700
FA7701
FA7700
FA7701
tf
Symbol
R
ONH
R
ONH
R
ONL
R
ONL
tr
Test condition
VCC=6V, source current= –50mA
VCC=2.5V, source current= –50mA
VCC=6V, sink current= +50mA
VCC=2.5V, sink current= +50mA
330pF load to GND terminal
330pF load to VCC terminal
330pF load to GND terminal
330pF load to VCC terminal
Min.
Typ.
10
18
5
5
20
25
45
40
Max.
20
36
10
10
Unit
Ω
Ω
Ω
Ω
ns
ns
ns
ns
Overall section (Supply current to VCC terminal)
Item
OFF mode supply current
Operating mode supply current
Latched mode supply current
Symbol
I
CCST1
I
CC0
I
CC1
I
CCLAT
Test condition
CS terminal=0V
Duty cycle=0%, OUT:Open, IN–=0V, FB:Open
Duty cycle=50%, OUT:Open, IN–, FB:Shorted
CS terminal >2.35V, IN–=0V, FB:Open
Min.
Typ.
40
0.9
1.2
0.9
Max.
100
1.5
2.0
1.5
Unit
µA
mA
mA
mA
4
FA7700V, FA7701V
s
Characteristic curves
Oscillation frequency (f
OSC
) vs.
timing resistor resistance (R
T
)
10000
Oscillation frequency (f
OSC
) vs. ambient temperature
5
4
Oscillation frequency variation [%]
Oscillation frequency [kHz]
3
2
1
0
1000
fosc=1MHz
fosc=185kHz
–1
–2
–3
–4
fosc=50kHz
100
10
1
10
100
–5
–40
–20
0
20
40
60
80
100
Timing resisitor R
T
[kΩ]
Ambient temperature Ta [˚C]
Duty cycle vs. FB terminal voltage
FA7700
100
90
80
70
Duty cycle vs. CS terminal voltage
FA7700
100
90
80
70
Duty cycle [%]
Duty cycle [%]
fosc=1MHz
60
50
40
30
60
50
40
30
20
10
0
0.5
0.7
0.9
fosc=1MHz
fosc=185kHz
20
10
1.1
1.3
0
0.5
0.7
fosc=185kHz
0.9
1.1
1.3
FB terminal voltage [V]
CS terminal voltage [V]
Duty cycle vs. FB terminal voltage
FA7701
100
90
80
70
Duty cycle vs. CS terminal voltage
FA7701
100
90
80
70
Duty cycle [%]
60
50
40
30
20
10
0
0.5
0.7
fosc=1MHz
Duty cycle [%]
fosc=1MHz
60
50
40
30
20
fosc=185kHz
fosc=185kHz
10
1.1
1.3
0
0.5
0.7
0.9
1.1
1.3
0.9
FB terminal voltage [V]
CS terminal voltage [V]
5
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