NJU7620

NJU7620
Step-Up/Flyback Switching Regulator IC with Constant Current Control
■ GENERAL DESCRIPTION
■ PACKAGE OUTLINE
The NJU7620 is a low voltage operation high-speed switching
regulator control IC for step-up and flyback converter, with a
constant current control. It incorporates a totem pole output, which
can drive an external MOS-FET easily. It also incorporates error
amplifier and current sense amplifier, which can allow the constant
voltage/current control for output voltage. Therefore the NJU7620 is
suitable for a LED driving and other CCCV applications up to 10W.
The NJU7620 is available in a small and thin 8-lead MSOP
(TVSP) package.
■ FEATURES
● PWM switching control
● Constant Current Control
● Operating Voltage
2.2V to 8V
● Wide Oscillator Range 300kHz to 1MHz
● Maximum Duty Cycle
90% typ.
● Quiescent Current
800µA typ.
● Soft-Start Function
Internal : 16ms typ. or adjustable
● Dead Time Control
● C-MOS Technology
● Package Outline
NJU7620RB1 : MSOP8 (TVSP8)*
NJU7620RB1
(MSOP8 (TVSP8))
■ PRODUCT VARIATION
NJU7620
Constant Current Control
NJU7610
Over Current Protection
NJU7600
PWM Control
*MEET JEDEC MO-187-DA / THIN TYPE
■PIN CONFIGURATION
1
8
2
7
3
6
4
5
NJU7620RB1
Ver.2012-08-03
PIN FUNCTION
1. V+
2. FB
3. IN-1
4. IN-2
5. DTC
6. RT
7. GND
8. OUT
-1-
NJU7620
■ BLOCK DIAGRAM
+
V
FB
0.8V
Error AMP
IN-1
−1
0.2V
1V
Soft Start
IN-2
−1
UVLO
0.2V
Current
Sense AMP
PWM
Buffer
OUT
OSC
0.5V
0.5
RT
0.74V
A
DTC
RT
GND
RT
-2-
Ver.2012-08-03
NJU7620
■ ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
Supply Voltage
V+
Output Pin Current
IO
Power Dissipation
PD
Operating Temperature Range
TOPR
Storage Temperature Range
TSTG
MAXIMUM RATINGS
+9
±50
MSOP8 (TVSP8) :320
-40 to +85
-40 to +125
■ RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
MIN.
Operating Voltage
V+
2.2
Oscillator Timing Resistor
RT
30
Oscillation Frequency
fOSC
300
TYP.
–
47
700
Under Voltage Lockout Block
ON Threshold Voltage
OFF Threshold Voltage
Hysteresis Voltage
Soft Start Block
Soft Start Time
Oscillator Block
RT Pin Voltage
Oscillation Frequency
Oscillate Supply Voltage
Fluctuations
Oscillate Temperature
Fluctuations
Ver.2012-08-03
SYMBOL
VT_ON
VT_OFF
VHYS
TSS
(Ta=25°C)
UNIT
V
kΩ
kHz
MAX.
8
120
1,000
(V+=3.3V, RT=47kΩ, Ta=25°C)
■ ELECTRICAL CHARACTERISTICS
PARAMETER
(Ta=25°C)
UNIT
V
mA
mW
°C
°C
TEST CONDITION
V+= L → H
V+= H → L
VT_ON → Duty=80%
VRT
fOSC
MIN.
TYP.
MAX.
UNIT
1.9
1.8
60
2.0
1.9
100
2.1
2.0
–
V
V
mV
8
16
24
ms
-5%
630
0.5
700
+5%
770
V
kHz
fDV
V+=2.2V to 8V
–
1
–
%
fDT
Ta=-40°C to +85°C
–
3
–
%
-3-
NJU7620
■ELECTRICAL CHARACTERISTICS (V+=3.3V, RT=47kΩ, Ta=25°C)
PARAMETER
Error Amplifier Block
Reference Voltage 1
Input Bias Current 1
Open Loop Gain 1
Gain Bandwidth Product 1
Output Source Current 1
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
-1.5%
-0.1
–
–
25
1.00
–
80
1
55
+1.5%
0.1
–
–
95
V
µA
dB
MHz
mA
4
9
16
mA
0.10
0.16
0.22
mA
VFB=1V, VIN-1=0.9V, VIN-2=0.3V
-10%
-0.1
–
–
0.10
0.2
–
70
1
0.16
+10%
0.1
–
–
0.22
V
µA
dB
MHz
mA
Duty=0%
Duty=50%
VFB=0.9V
VFB=0.9V, RDTC=47kΩ
0.16
0.44
85
40
0.22
0.5
90
50
0.28
0.56
95
60
V
V
%
%
VB1
IB1
AV1
GB1
IOM+_1
IOM+_2
Output Sink Current 1
IOM1-
Current Sense Amplifier Block
Reference Voltage 2
Input Bias Current 2
Open Loop Gain 2
Gain Bandwidth Product 2
Output Sink Current 2
VB2
IB2
AV2
GB2
IOM2-
VFB=1V, VIN-1=0.9V, VIN-2=0.1V
VFB=1V, VIN-1=0.9V, VIN-2=0.1V,
V+=2.2V
VFB=1V, VIN-1=1.1V, VIN-2=0.1V
PWM Comparate Block
Input Threshold Voltage
Maximum Duty Cycle
Output Block
Output High Level
ON Resistance
Output Low Level
ON Resistance
General Characteristics
Quiescent Current
-4-
VT_0
VT_50
MAXDUTY_1
MAXDUTY_2
ROH
IO=-20mA
–
10
20
Ω
ROL
IO=+20mA
–
5
10
Ω
RL=Non Load
–
800
1200
µA
IDD
Ver.2012-08-03
NJU7620
■ TYPICAL APPLICATIONS
Step-Up Converter
SBD
L
+
V
VOUT
CIN
NJU7620
C
CCNF
R2
+
V
OUT
8
2
FB
GND
7
3
IN-1
RT
6
4
IN-2
DTC
5
R1
CNF
RCNF
COUT
FET
1
GNDOUT
RSC
RT
RNF
RDTC
CS
RCIN
Flyback Converter
T
+
V
SBD
VOUT
CIN
NJU7620
C
CCNF
RCNF
R2
1
V
2
+
FET
OUT
8
FB
GND
7
3
IN-1
RT
6
4
IN-2
DTC
5
CNF
GNDOUT
COUT
R1
RSC
RT
RNF
RDTC
CS
RCIN
Ver.2012-08-03
-5-
NJU7620
■TYPICAL CHARACTERISTICS
Oscillation Frequency vs. Timing Resistance
+
+
(V =3.3V, Ta=25 C)
90
AX
UTY_1
95
100
10
85
80
100
100
Timing Resistance RT (kΩ)
Duty Cycle vs. R
DTC
100
T
720
700
680
660
2
4
6
8
+
Operating Voltage V (V)
10
(V =3.3V, R =47kΩ, Ta=25 C)
T
80
60
40
20
0
0
o
+
Duty Cycle MAXDUTY (%)
Oscillation Frequency fosc (kHz)
(R =47kΩ, Ta=25oC)
740
1000
Oscillator Frequency fOSC (kHz)
Oscillation Frequency vs. Operating Voltage
-6-
o
(V =3.3V, Ta=25 C)
100
Maximum Duty Cycle
M D
(%)
1000
Oscillation Frequency fOSC (kHz)
Maximum Duty Cycle vs. Oscillator Frequency
o
0
20
40
60
80
100
Dead Time Control Resistance RDTC (kΩ)
Ver.2012-08-03
NJU7620
■TYPICAL CHARACTERISTICS
(V)
0.998
0
2
4
6
8
+
Operating Voltage V (V)
0.202
0.2
0.198
0.196
10
(R =47kΩ, R =Non Load, Ta=25oC)
T
60
Voltage Gain Av (dB)
L
1200
1000
800
600
400
2
4
6
8
+
Operating Voltage V (V)
Error Amplifier Block
Voltage Gain, Phase vs. Frequency
(V+=3.3V, Gain=40dB, Ta=25 oC)
Quiescent Current vs. Operating Voltage
1400
0
Phase
45
10
180
135
Gain
30
90
15
45
Phase Φ (deg)
1
Quiescent Current IDD (µA)
(Ta=25oC)
0.204
B2
Reference Voltage2 V
Reference Voltage1 V
1.002
0.996
Current Sense Amplifier Block
Reference Voltage2 vs. Operating Voltage
(Ta=25oC)
1.004
B1
(V)
Error Amplifier Block
Reference Voltage1 vs. Operating Voltage
200
0
0
Ver.2012-08-03
2
4
6
8
+
Operating Voltage V (V)
10
0
0.1
1
10
100
1000
Frequency f (kHz)
0
10000
-7-
NJU7620
■TYPICAL CHARACTERISTICS
Output High Level ON Resistance
ROH (Ω)
14
+
V =1.95V
12
8
V+=3.3V
6
4
V+=8V
2
0
-50
Output Source Current I
12
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
Error Amplifier Block
Output Source Current1 vs. Temperature
(VFB=1V, VIN-1 =0.9V, VIN-2 =0.1V)
Output Sink Current IOM- (mA)
1000
Output Block
Output Low Level ON Resistance
vs. Temperature (Io=+20mA)
V+=1.95V
10
V+=8V
OM+
(mA)
10
14
Output Low Level ON Resistance
ROL (Ω)
Output Block
Output High Level ON Resistance
vs. Temperature (Io=-20mA)
100
V+=3.3V
10
V+=1.95V
1
-50
8
V+=3.3V
6
4
2
0
-50
V+=8V
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
Error Amplifier, Current Sense Amplifier Block
Output Sink Current vs. Temperature
0.2
0.15
V+=1.95V, 3.3V, 8V
0.1
0.05
-25
0
25 50 75 100 125
o
Ambient Temperature Ta ( C)
0
-50
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
Soft Start Time vs. Temperature
Soft Start Time Tss (ms)
24
22
20
18
16
14
12
10
8
-50
-8-
(V+=3.3V)
-25
0
25 50 75 100 125
o
Ambient Temperature Ta ( C)
Ver.2012-08-03
NJU7620
■TYPICAL CHARACTERISTICS
Current Sense Amplifier Block
Reference Voltage2 vs. Temperature
Error Amplifier Block
Reference Voltage1 vs. Temperature
(V+=3.3V)
(V)
Reference Voltage2 VB2 (V)
1.01
0.205
B1
Reference Voltage1 V
(V+=3.3V)
0.21
1.005
1
0.2
0.195
0.995
0.99
-50
0.19
-50
-25
0
25 50 75 100 125
o
Ambient Temperature Ta ( C)
Oscillator Frequency vs. Temperature
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
Muximum Duty Cycle vs. Temperature
760
80
700
60
660
Ver.2012-08-03
40
-50
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
VT_ON
VT_OFF
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
Quiescent Current vs. Temperature
Under Voltage Lockout Block
vs. Temperature
1.94
1.86
-50
MAX DUTY_2
50
2.02
1.9
MAX DUTY_1
70
680
1.98
(V+=3.3V)
90
720
640
-50
100
Muximum Duty Cycle
MAX DUTY (%)
740
2.06
Threshold Voltage (V)
(V =3.3V, RT=47kΩ)
1000
Quiescent Current IDD (µA)
Oscillator Frequency fOSC (kHz)
+
(V+=3.3V, RT=47kΩ)
800
600
400
200
0
-50
-25
0
25 50 75 100 125
Ambient Temperature Ta (oC)
-9-
NJU7620
MEMO
[CAUTION]
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.
- 10 -
Ver.2012-08-03