NJU7680
2ch switching regulator IC
■GENERAL
DESCRIPTION
The
NJU7680
is a high-speed low voltage operation switching
regulator control IC. It features a totem pole driver that can directly
drive an external MOS-FET.
Each channel has an on/off switch. Therefore, the power
sequence can be activated externally.
Internal soft-start function, dead time control and timer latch
function are included, and those functions can be easily controlled
by external component.
■PACKAGE
OUTLINE
NJU7680V
NJU7680SED
(U.D.)
■FEATURES
●
Step-Down, Step-Up/SEPIC circuit
●
PWM switching control
●
Operating Voltage
2.3V to 7V
●
Wide Oscillator Range
300kHz to 1MHz
●
Soft-Start Function
Internal: 4ms typ. or adjustable
●
Channel ON/OFF Function
●
Standby Quiescent Current
1µA max.
●
Dead Time Control
●
Timer Latch for Short Circuit Protection
●
C-MOS Technology
●
Package Outline
NJU7680V
: SSOP16
NJU7680SED
: PCSP24-ED (U.D.)
Ver.2010-03-31
-1-
NJU7680
■PIN
CONFIGURATION
<SSOP16 package>
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PIN FUNCTION
1. SCP
2. CE1
3. CE2
4. FB2
5. IN-2
6. V
+
7. DTC2
8. OUT2
9. OUT1
10. DTC1
11. GND
12. GND
13. RT
14. VREG
15. IN-1
16. FB1
(Top View)
NJU7680V
<PCSP24-ED package>
18
17
16
15
14
13
13
14
15
16
17
18
19
20
21
22
23
24
12
11
10
9
8
7
12
11
PAD (*1)
10
9
PAD (*1)
8
7
PAD (*1)
PAD (*1)
19
20
21
22
23
24
1
2
3
4
5
6
6
5
4
3
2
1
PIN FUNCTION
1. N.C.
2. FB2
3. IN-2
4. N.C.
5. V
+
6. N.C.
7. DTC2
8. N.C.
9. OUT2
10. N.C.
11. OUT1
12. N.C.
13. DTC1
14. GND
15. GND
16. RT
17. VREG
18. N.C.
19. IN-1
20. FB1
21. N.C.
22. SCP
23. CE1
24. CE2
(Top View)
NJU7680SED (U.D.)
(Bottom View)
(*1) The PAD is not connected to an IC chip electrically.
-2-
Ver.2010-03-31
NJU7680
■BLOCK
DIAGRAM
VREG
V
+
Vref
1V
V
+
2µA
Regulator
2V
UVLO
SCP
2kΩ
1V
RT_ON
CE1
ON/OFF
1V
SCP
CE2
FB1
IN-1
ER⋅AMP1
SST1
DTC_COMP1
PWM1
Buffer1
OUT1
DTC1
CH1
FB2
IN-2
ER⋅AMP2
SST2
DTC_COMP2
PWM2
Buffer2
OUT2
DTC2
CH2
0.8V
0.2V
OSC
0.5V
RT_ON
GND
RT
R
T
V
+
R
P
SW
•On/Off
Function
The On/Off switch for each channel is controlled by CE pin.
→
Setting the CE low will turn off all applicable channels’ circuit.
→
Turning off both channels will turn off all circuit.
→
Opening the RT pin will turn off all circuit regardless of input signals from CE pin.
Input Signal
CE1
H
H
L
L
H
H
L
L
Operating State
CH1
CH2
ON
ON
ON
OFF
OFF
ON
OFF
Standby Mode
RT
H
H
H
H
L
L
L
L
CE2
H
L
H
L
H
L
H
L
Ver.2010-03-31
-3-
NJU7680
•Soft
Start Feature (Soft Start)
The soft-start is internally set for 4ms typ. To adjust the time, insert resistance or connect capacitor to the DTC pin.
•Max
Duty
Max Duty is set 90% for CH1 (Step-up) and 100% for CH2 (Step-down).
Max Duty can be adjusted by connecting the VERG pin to the DTC pin. When not limiting Max Duty, short the DTC pin
to the VREG terminal.
•Short
Circuit Protection
The short circuit protection block employs time latch, and protection delay time can be adjusted by a capacitor
connected to SCP pin. The program of timer latch circuit can be reset by restarting the power (supply voltage must be
lower than UVLO sensing voltage), setting IC to standby status, or lowering SCP pin to GND level.
■ABSOLUTE
MAXIMUM RATINGS (Ta=25°C)
PARAMETER
SYMBOL
Supply Voltage
V
+
Output Pin Current
I
O
CE1 Pin Voltage
V
CE1
CE2 Pin Voltage
V
CE2
Power Dissipation
Operating Temperature Range
Storage Temperature Range
P
D
T
OPR
T
STG
°C
°C
(*2): When input voltage is less than 8V, the absolute maximum control voltage is equal to the input voltage.
(*3): Mounted on glass epoxy board based on EIA/JEDEC. (114.3 × 76.2 × 1.6mm: 2Layers)
MAXIMUM RATINGS
+8
±50
+8 (*2)
+8 (*2)
SSOP16
: 300
PCSP24-ED : 475 (*3)
-40 ~ +85
-40 ~ +125
UNIT
V
mA
V
V
mW
■RECOMMENDED
OPERATING CONDITIONS (Ta=25°C)
PARAMETER
SYMBOL
MIN.
+
Operating Voltage
V
2.3
Oscillator Timing Resistor
30
R
T
Oscillation Frequency
f
OSC
300
TYP.
–
47
700
MAX.
7
120
1,000
UNIT
V
kΩ
kHz
-4-
Ver.2010-03-31
NJU7680
■ELECTRICAL
CHARACTERISTICS (V
+
=V
CE1
=V
CE2
=3.3V, R
T
=47kΩ, Ta=25°C)
PARAMETER
Voltage Regulator Block
Regulator Output Voltage
Line Regulation
Load Regulation
Maximum Output Current
Temp Fluctuations
Under Voltage Lockout Block
ON Threshold Voltage
OFF Threshold Voltage
Hysteresis Voltage
Regulator Output Detection
ON Threshold Voltage
Regulator Output Detection
OFF Threshold Voltage
Regulator Output Detection
Hysteresis Voltage
Short Circuit Protection Block
Input Threshold Voltage 1
Input Threshold Voltage 2
Charge Current
Latch Mode
ON Threshold Voltage
Latch Mode
OFF Threshold Voltage
Soft Start Block
Soft Start Time 1
Soft Start Time 2
Oscillator Block
RT Pin Voltage
Oscillation Frequency
Oscillate Supply
Voltage Fluctuations
Oscillate Temperature
Fluctuations
Standby RT Terminal
Resistance
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
V
REG
V
REG_LINE
V
REG_LOAD
I
REG_MAX
V
REG_TC1
V =2.2
∼
7V
I
REG
=0
∼
2mA
V
REG
=1.9V
Ta=-40
∼
+85°C
+
1.97
–
-10
4
–
2.0
±5
-1
–
±0.5
2.03
±15
–
–
–
V
mV
mV
mA
%
V
T_ON
V
T_OFF
V
HYS
V
T_ON_REG
V
+
= L
→
H
V
+
= H
→
L
V
REG
= L
→
H
2.1
2.0
60
1.6
1.5
60
2.2
2.1
100
1.7
1.6
100
2.3
2.2
–
1.8
1.7
–
V
V
mV
V
V
mV
V
T_OFF_REG
V
REG
= H
→
L
V
HYS_REG
V
T_PC1
V
T_PC2
I
CHG
V
T_LA
V
T_LAOFF
FB1 Pin
FB2 Pin
V
SCP
=0V
SCP Pin
SCP Pin
0.95
0.95
1.5
0.90
0.35
1.00
1.00
2
1.00
0.6
1.05
1.05
2.5
1.10
0.85
V
V
µA
V
V
T
SS1
T
SS2
V
T_ON
→
Duty1=80%
V
T_ON
→
Duty2=80%
3
3
4
4
6
6
ms
ms
V
RT
f
OSC
f
DV
f
DT
R
T_STB
V
+
=2.2 ~ 7V
Ta=-40°C ~ +85°C
-5%
630
–
–
–
0.5
700
1
3
2
+5%
770
–
–
–
V
kHz
%
%
MΩ
Ver.2010-03-31
-5-
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