FUJI FA3675F

CMOS IC
For Switching Power Supply Control
FA3675F
FA3675F
■ Description
■ Dimensions, mm
FA3675F is a control IC for 6-channel DC-DC converter.
This IC can directly drive a Nch/Pch-MOSFET.
This IC is suitable to reduce converter size because it has
many functions in a small package LQFP-48.
Á LQFP-48
9.0±0.3
1.45 max
0.10±0.06
7.0
■ Application
• VTR-camera, digital-steel-camera and portable equipment
122
7.8
8.0
13
7.0
24
25
37
36
48
1
12
0.5±0.1
0.2±0.06
0.5±0.2
• 6-channel PWM control with MOSFET direct driving :
5-channel for Pch-MOSFET, 1channel for Nch-MOSFET
• Low input voltage: 2.5V to 20V
• ±1.0% high accuracy bandgap reference
• Low power consumption by means of CDMOS
Standby mode: 20µA(max.)
Operating mode: 10mA(max.)
• Soft start function for each channel
• ON/OFF function for each channel
• Timer latch for short protection
• Undervoltage lockout
• Wide range of operation frequency: 50kHz to 1MHz
• Package: LQFP-48(Thin and small)
9.0±0.3
■ Features
±0.05
0.127
˚
0~7
FA3675F
■ Block diagram
123
FA3675F
Pin
No.
Pin
symbol
Description
Pin
No.
Pin
symbol
Description
1
VCC1
Power supply for control circuit
25
IN4-
Ch. 4 inverting input to error amplifier
2
RT
Oscillator timing resistor
26
FB4
Ch. 4 output of error amplifier
3
CT
CS3
Oscillator timing capacitor
27
Soft start for Ch. 3 & Ch. 4
28
CP
GND
Timing capacitor for timer latch delay
4
5
CS5
Soft start for Ch. 6
29
TLSEL
Ch. 3 & Ch. 4 timer latch selection (Low: disable)
6
CS4
Soft start for Ch. 5
30
CNT5
Ch. 6 ON/OFF function
7
CS1
Soft start for Ch. 1
31
CNT4
Ch. 5 ON/OFF function
8
Soft start for Ch. 2
32
Reference voltage output
33
CNT2
CNT3
Ch. 2 ON/OFF function
9
CS2
VREF
10
CREF
Capacitor for reference voltage output
34
CNT1
Ch. 1 ON/OFF function
11
VREG
Regulated voltage output
35
VCC2
Power supply for output stage
12
IN2-
Ch. 2 inverting input to error amplifier
36
VDRV
Bias for logic circuit of outputs
13
FB2
IN1-
Ch. 2 output of error amplifier
37
Ch. 1 inverting input to error amplifier
38
PGND1
OUT1S
Power ground
14
15
FB1
Ch. 1 output of error amplifier
39
OUT1
Ch. 1 output (for Pch-MOSFET)
16
IN5+
Ch. 5 non-inverting input to error amplifier
40
OUT4
Ch. 4 output (for Pch-MOSFET)
17
IN5-
Ch. 5 inverting input to error amplifier
41
OUT3
Ch. 3 output (for Pch-MOSFET)
18
Ch. 5 output of error amplifier
42
Ch. 6 inverting input to error amplifier
43
OUT2S
OUT2
Ch. 2 source electrode of output stage
19
FB5
IN6-
20
FB6
Ch. 6 output of error amplifier
44
OUT6S
Ch. 6 source electrode of output stage
21
IN3+
Ch. 3 non-inverting input to error amplifier
45
OUT6
Ch. 6 output (for Nch-MOSFET)
22
IN3-
Ch. 3 inverting input to error amplifier
46
OUT5
Ch. 5 output (for Pch-MOSFET)
23
FB3
Ch. 3 output of error amplifier
47
OUT5S
Ch. 5 source electrode of output stage
24
IN4+
Ch. 4 non-inverting input to error amplifier
48
PGND2
Power ground
Ground
Ch. 3 & Ch. 4 ON/OFF function
Ch. 1 source electrode of output stage
Ch. 2 output (for Pch-MOSFET)
■ Absolute maximum ratings
Item
Symbol
Rating
Unit
Power supply voltage
20.0
V
–200
mA
Input voltage for analog input
VCC
IOUT
IOUT
VANA
Input voltage for logic input
Total power dissipation *
Source peak current
Sink peak current
200
mA
–0.3 to +2.5
V
VLOG
–0.3 to Vcc +0.5 (Vcc ≤ 5.0V)
–0.3 to +5.5 (Vcc > 5.0V)
V
Pd
TJ
TOP
Tstg
550
mW
125
°C
Symbol
Min.
Max.
Unit
VCC
VLOG
2.5
18.0
V
0.0
0.0
Vcc +0.25
5.25
V
Oscillation frequency
fOSC
50
1000
kHz
Oscillator timing resistor
RT
CT
CREF
6.8
100
kΩ
22
1000
pF
Junction temperature
Ambient temperature
Storage temperature
–20 to +85
°C
–40 to +150
°C
* Ta < 25°C
■ Recommended operating conditions
Item
Power supply voltage
Input voltage for logic input
Oscillator timing capacitor
CREF terminal by-pass capacitor
124
Vcc ≤ 5.0
Vcc > 5.0
0.01
µF
FA3675F
■ Electrical characteristics (Ta=25°C, Vcc1=Vcc2=6V, CT=100pF, RT=10kΩ)
Reference voltage section
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Output voltage
VREF
VRFLOD
No load
0.99
1.00
1.01
V
No load to RL=15kΩ
7
15
mV
VRFLIN
VRTa
VCC=2.5 to 18V
Ta=–20 to +85°C
3
10
mV
±0.5
±1.0
%
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Output voltage
VREG
No load
2.134
2.20
2.266
V
Load regulation
VRG LOD
VRG LIN
VRGTa
No load to RL=3.9kΩ
2
10
mV
VCC=2.5 to 18V
Ta=–20 to +85°C
6
20
mV
±0.5
±1.0
%
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
Oscillation frequency
fOSC
RT=10kΩ, CT=100pF
432
480
528
kHz
Frequency variation due to supply voltage change
fdV
fdT
VCC=2.5 to 18V
Ta=–20 to +25°C
Ta=+25 to +85°C
±1
±3
%
±3
±6
%
±7
±14
Typ.
Max.
Unit
2
10
mV
1.5
V
Load regulation
Line regulation
Output voltage variation due to temperature change
Regulated voltage section
Line regulation
Output voltage variation due to temperature change
Oscillator section
Frequency variation due to temperature change
Error amplifier section
Item
Symbol
Input offset voltage
VIOF
Input common mode voltage range
VICOM
AVOL
fT
IFBL
IFBH
VFB=VREF +0.05V
VFB=VREF -0.05V
2.5
Item
Symbol
Test condition
Input threshold voltage
VCSO
VCS100
ICS
Duty cycle=0%
Item
Input threshold voltage
Open-loop gain
Unity-gain bandwidth
Output sink current
Output source current
Test condition
Min.
0.2
70
75
dB
1.0
MHz
3.5
mA
–0.18
–0.14
mA
Min.
Typ.
Max.
Unit
0.36
0.46
0.56
V
Soft-start circuit section 1 (CS1, CS2, CS3)
Charge current
Duty cycle=100%
1.11
1.31
1.51
V
VCS=0V
–7.5
–5.0
–2.5
µA
Symbol
Test condition
Min.
Typ.
Max.
Unit
VCSO
VCS100
ICS
Duty cycle=0%
0.36
0.46
0.56
V
Duty cycle=100%
1.11
1.31
1.51
Soft-start circuit section 2 (CS4, CS5)
Charge current
0
V
µA
125
FA3675F
Short-circuit protection section
Item
Symbol
Threshold voltage at CP
VCPTH
ICP
VFBTL
Charge current at CP
Threshold voltage at error amplifier output
Test condition
Min.
Typ.
Max.
Unit
1.39
1.64
1.89
V
–3.0
–1.9
–1.0
µA
1.36
1.56
1.76
V
Typ.
ON/OFF logic input section
Item
Symbol
Test condition
Min.
Max.
Unit
Input voltage for ON mode
VDH
Vcc≤5.0V
1.0
Vcc
+0.25
V
Vcc>5.0V
1.0
5.25
Input voltage for OFF mode
VDL
0
0.4
V
Undervoltage lockout circuit section
Item
Symbol
OFF to ON threshold voltage
VUVVCC
∆UVCC
Voltage hysteresis
Test condition
Min.
Typ.
Max.
Unit
1.52
1.72
1.92
V
0.1
V
Output section 1 (OUT1)
Item
Symbol
Test condition
L-level ON resistance
H-level ON resistance
RONL
RONH
Rise time
tr
Min.
Typ.
Max.
Unit
6
10
Ω
6
10
Ω
30
50
ns
Fall time
tf
IO=10mA, OUT1S:GND
IO=–10mA, OUT1S:GND
CLOAD=1000pF, OUT1S:GND
CLOAD=1000pF, OUT1S:GND
60
85
ns
Sink current
IOUT
OUT1S:RS1=68Ω to GND
9
12
15
mA
Item
Symbol
Test condition
Min.
Typ.
Max.
Unit
L-level ON resistance
RONL
IO=10mA
10
15
Ω
10
15
Ω
40
60
ns
70
95
ns
Output section 2 (OUT2, OUT5)
H-level ON resistance
RONH
Rise time
tr
Fall time
tf
OUT2S, OUT5S:GND
IO=–10mA
OUT2S, OUT5S:GND
CLOAD=1000pF
OUT2S, OUT5S:GND
CLOAD=1000pF
OUT2S, OUT5S:GND
Sink current
IOUT
OUT2S, OUT5S:
RS2, RS5=68Ω to GND
8
11
14
mA
Min.
Typ.
Max.
Unit
10
15
Ω
10
15
Ω
40
60
ns
70
95
ns
Output section 3 (OUT3, OUT4)
Item
Symbol
Test condition
L-level ON resistance
H-level ON resistance
RONL
RONH
Rise time
tr
Fall time
tf
IO=10mA
IO=–10mA
CLOAD=1000pF
CLOAD=1000pF
Output section 4 (OUT6)
Item
Symbol
Test condition
L-level ON resistance
H-level ON resistance
RONL
RONH
Rise time
tr
Fall time
tf
IO=10mA, OUT6S:VCC2
IO=–10mA, OUT6S:VCC2
CLOAD=1000pF, OUT6S:VCC2
CLOAD=1000pF, OUT6S:VCC2
Source current
IOUT
OUT6S:RS6=330Ω to VCC2
VCC=7V
Item
Symbol
Test condition
Standby current
ICCO
ICC
Min.
Typ.
Max.
Unit
10
15
Ω
10
15
Ω
40
60
ns
70
95
ns
-14
-11
-8
mA
Min.
Typ.
Max.
Unit
12
20
µA
4
6
mA
Overall device
Operating-state supply current
126
Duty cycle=0%, RL= ∞
FA3675F
■ Characteristic curves (Ta = 25°C)
Oscillation frequency (fOSC) vs.
timing resistor resistance (RT)
Oscillation frequency (fOSC ) vs.
ambient temperature (Ta)
1000
520
500
CT
=2
F
56
pF
10
fosc [kHz]
fOSC [kHz]
9p
0p
100
50
F
0p
F
480
460
440
420
10
10
400
20
100
20
0
40
100
100
90
90
80
80
70
60
50
40
30
60
50
40
30
20
10
10
0.2
0.4
0.6
0.8
100
70
20
0
80
Output duty cycle vs. FB terminal voltage (V FB)
Output duty cycle [%]
Output duty cycle [%]
Output duty cycle vs. CS terminal voltage (VCS)
0
60
Ta [°C]
RT [kΩ]
1
1.2
1.4
0
1.6
0
0.2
0.4
0.6
1.2
1
0.8
1.4
1.6
VFB [V]
Vcs [V]
Reference voltage (VREF) vs ambient temperatare (Ta)
Supply current (Icc) vs supply voltage (Vcc)
CT=100pF, RT=10kΩ
10
1.06
9
8
1.04
1.02
Icc [mA]
VREF [V]
7
0%
le 6
yc
ty c
6
Du
5
4
1
Duty cycle 0%
3
Duty cycle 100%
2
0.98
1
0.96
20
0
0
20
40
Ta [°C]
60
80
100
0
5
10
15
20
Vcc [V]
127
FA3675F
H-level output voltage (VCC-VOH) vs.
output source current (ISOURCE) for OUT1
L-level output voltage(VOL) vs. output sink current (ISINK )
for OUT1
2.2
2
2
1.8
1.8
1.6
1.6
1.4
1.4
VOL [V]
VCC–VOH [V]
2.2
1.2
1
1.2
1
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
100
50
0
200
150
0
50
100
150
200
ISINK [mA]
ISOURCE [mA]
H-level output voltage (VCC-VOH) vs.
output source current (ISOURCE) for OUT2, 3, 4, 5, 6
L-level output voltage(VOL) vs.
output sink current (ISINK) for OUT2, 3, 4, 5, 6
1.8
1.4
1.6
1.2
1.4
1
VOL [V]
VCC–VOH [V]
1.2
1
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
50
150
100
ISOURCE [mA]
Condition: Open loop
160
140
120
AV [dB]
[deg]
100
80
60
Av
40
20
0
–20
–40
–60
10
100
1K
10K
f [Hz]
128
0
50
100
ISINK [mA]
Error amplifier voltage gain(Av) / phase(θ) vs. frequency(f)
180
0
100K
1M
10M
150
FA3675F
■ Application circuit
Parts tolerances characteristics are not defined in the circuit design
sample shown above. When designing an actual circuit for a product,
you must determine parts tolerances and characteristics for safe and
economical operation.
129