NJU7677
1.8V Operate PWM control Step-Up / Flyback switching regulator IC
■GENERAL
DESCRIPTION
NJU7677
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.
Internal soft-start function, dead time control and timer latch
function are included, requiring no external components. All
parameters can be optimized by additional external components for
design flexibility.
■PACKAGE
OUTLINE
NJU7677RB1
■FEATURES
●
PWM switching control
●
Operating Voltage
1.8V to 7V
●
Wide Oscillator Range 300kHz to 1MHz
●
Maximum Duty Cycle
90% typ.
●
Quiescent Current
600µA typ.
●
Soft-Start Function
Internal : 4ms typ. or adjustable
●
Dead Time Control
●
Timer Latch for Short Circuit Protection
●
C-MOS Technology
●
Package Outline
NJU7677RB1 : TVSP8
■PIN
CONFIGURATION
PIN FUNCTION
1. V
+
2. FB
3. IN-
4. SCP
5. DTC
6. RT
7. GND
8. OUT
1
2
3
4
8
7
6
5
NJU7677RB1
Ver.2009-09-08
-1-
NJU7677
■ABSOLUTE
MAXIMUM RATINGS (Ta=25°C)
PARAMETER
SYMBOL
Supply Voltage
V
+
Output Pin Current
I
O
Power Dissipation
P
D
Operating Temperature Range
T
OPR
Storage Temperature Range
T
STG
MAXIMUM RATINGS
+8
±50
320
-40 ~ +85
-40 ~ +125
UNIT
V
mA
mW
°C
°C
■RECOMMENDED
OPERATING CONDITIONS (Ta=25°C)
PARAMETER
SYMBOL
MIN.
+
Operating Voltage
V
1.8
Oscillator Timing Resistor
R
T
30
Oscillation Frequency
f
OSC
300
TYP.
–
47
700
MAX.
7
120
1,000
UNIT
V
kΩ
kHz
■ELECTRICAL
CHARACTERISTICS (V
+
=3.3V, R
T
=47kΩ, Ta=25°C)
PARAMETER
Under Voltage Lockout Block
ON Threshold Voltage
OFF Threshold Voltage
Hysteresis Voltage
Soft Start Block
Soft Start Time
Short Circuit Protection Block
Input Threshold Voltage
Charge Current
Latch Mode
ON Threshold Voltage
Latch Mode
OFF Threshold Voltage
Oscillator Block
RT Pin Voltage
Oscillation Frequency
Oscillate Supply Voltage
Fluctuations
Oscillate Temperature
Fluctuations
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
V
T_ON
V
T_OFF
V
HYS
V
+
= L
→
H
V
+
= H
→
L
1.6
1.5
60
1.7
1.6
100
1.8
1.7
–
V
V
mV
T
SS
V
T_ON
→
Duty=80%
2
4
8
ms
V
T_PC
I
CHG
V
T_LA
V
T_LAOFF
FB Pin
V
SCP
=0V
SCP Pin
SCP Pin
0.95
1.5
0.90
0.35
1.00
2
1.00
0.6
1.05
2.5
1.10
0.85
V
µA
V
V
V
RT
f
OSC
f
DV
f
DT
V
+
=1.8V ~ 7V
Ta=-40°C ~ +85°C
-8%
630
–
–
0.5
700
1
3
+8%
770
–
–
V
kHz
%
%
Ver.2009-09-08
-3-
ARM技术
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