NJRC NJU7691RB1

NJU7691
300mA Synchronous Step-Down switching regulator IC
■GENERAL DESCRIPTION
■PACKAGE OUTLINE
The NJU7691 is a synchronous rectification type switching
regulator IC with a power MOSFET (300mA output).
It has an over current detection and an overheat protection
circuit. Therefore, the circuit can be configured with few
external parts.
The output voltage can be set from 0.8V. It is suitable for
supplying power to a digital chip and a logic IC with low
voltage.
NJU7691RB1
■FEATURES
● 300mA Synchronous Step-Down
● PWM switching control
● Operating Voltage
2.2V to 7V
● Wide Oscillator Range 300kHz to 1MHz
● Maximum Duty Cycle
100%
● Stand-by Current
5µA max.
● Soft-Start Function
4ms typ.
● Over Current Protection
● C-MOS Technology
● Package Outline
NJU7691RB1 : TVSP8
■PIN CONFIGURATION
1
8
2
7
3
6
4
5
NJU7691RB1
Ver.2010-04-14
PIN FUNCTION
1. SW
2. V+
3. FB
4. IN5. ON/OFF
6. RT
7. AGND
8. PGND
-1-
NJU7691
■BLOCK DIAGRAM
V
+
0.8V
FB
ER⋅AMP
0.2V
IN-
OCP
0.8V
Vref
PWM
UVLO
Soft Start
Buffer
SW
Standby
ON/OFF
100kΩ
OSC
TSD
0.5V
ON/OFF
High: ON
Low : OFF (Standby)
-2-
RT
AGND
PGND
RT
Ver.2010-04-14
NJU7691
■ABSOLUTE MAXIMUM RATINGS (Ta=25°C)
PARAMETER
SYMBOL
Supply Voltage
V+
ON/OFF pin Voltage
VON/OFF
Power Dissipation
PD
Operating Temperature Range
Topr
Storage Temperature Range
Tstg
MAXIMUM RATINGS
+8
+8
580 (*1)
-40 ~ +85
-40 ~ +150
UNIT
V
V
mW
°C
°C
(*1): Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 2-Layers)
■RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Operating Voltage
V+
Output Current (*2)
IOUT
Oscillator Timing Resistor
RT
Oscillation Frequency
fOSC
(*2): Steady Operating
MIN.
2.2
–
30
300
TYP.
–
–
47
700
MAX.
7
300
120
1,000
UNIT
V
mA
kΩ
kHz
■ELECTRICAL CHARACTERISTICS (V+=VON/OFF=3.3V, RT=47kΩ, Ta=25°C)
PARAMETER
Under Voltage Lockout Block
ON Threshold Voltage
OFF Threshold Voltage
Hysteresis Voltage
Soft Start Block
Soft Start Time
Oscillator Block
Oscillation Frequency
Oscillate Supply Voltage
Fluctuations
Oscillate Temperature
Fluctuations
Error Amplifier Block
Reference Voltage
Input Bias Current
Open Loop Gain
Gain Bandwidth Product
Output Source Current
Output Sink Current
Ver.2010-04-14
SYMBOL
VT_ON
VT_OFF
VHYS
TSS
TEST CONDITION
V+= L → H
V+= H → L
VT_ON → Duty=80%
fOSC
+
MIN.
TYP.
MAX.
UNIT
1.9
1.8
60
2.0
1.9
100
2.1
2.0
–
V
V
mV
2
4
8
ms
630
700
770
kHz
fDV
V =2.2V ~ 7V
–
1
–
%
fDT
Ta=-40°C ~ +85°C
–
3
–
%
VFB=1V, VIN-=0.7V
VFB=1V, VIN-=0.9V
-1.0%
-0.1
–
–
20
1
0.8
–
80
1
35
2.5
+1.0%
0.1
–
–
50
5
V
µA
dB
MHz
µA
mA
VB
IB
AV
GB
IOM+
IOM-
-3-
NJU7691
■ELECTRICAL CHARACTERISTICS (V+=VON/OFF=3.3V, RT=47kΩ, Ta=25°C)
PARAMETER
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
0.16
0.44
100
0.22
0.50
–
0.28
0.56
–
V
V
%
PWM Comparate Block
VT_0
VT_50
MAXDUTY
Input Threshold Voltage
Maximum Duty Cycle
Output Block
Output High Level
ON Resistance
Output Low Level
ON Resistance
Switching Current Limit
High Side SW Leak Current
Output Pull-Down Resistance
Duty=0%
Duty=50%
VFB=0.9V
ROH
ISW=-200mA
–
0.9
1.2
Ω
ROL
ISW=+200mA
–
0.8
1.1
Ω
VON/OFF=0V
500
–
60
650
–
100
800
1
140
mA
µA
kΩ
VON/OFF= L → H
VON/OFF= H → L
1.6
0
–
–
V+
0.3
V
V
–
–
1.3
–
1.6
5
mA
µA
ILIM
ILEAKH
RPD-SW
ON/OFF Block
ON Control Voltage
OFF Control Voltage
VON
VOFF
General Characteristics
Quiescent Current
Standby Current
IDD
RL=Non Load
VON/OFF=0V
IDD_STB
■ TYPICAL APPLICATIONS
VIN
RNF
CIN
CNF
L
VOUT
4
3
2
IN-
FB
V
+
CFB
1
R2
SW
SBD
COUT
RFB
NJU7691
ON/
OFF
RT
5
6
AGND PGND
7
R1
8
RT
ON/OFF
High: ON
Low: OFF
(Standby)
-4-
Ver.2010-04-14
NJU7691
■TYPICAL CHARACTERISTICS
Oscillation Frequency vs. Operating Voltage
Oscillation Frequency vs. Timing Resistance
o
o
Oscillation Frequency fosc (kHz)
(V =3.3V, Ta=25 C)
1000
Oscillation Frequency f
OSC
(kHz)
+
100
10
(R =47kΩ, Ta=25 C)
T
740
720
700
680
660
100
Timing Resistance R (kΩ)
0
2
4
6
Operating Voltage V+ (V)
T
Reference Voltage vs. Operating Voltage
Switching Current Limit vs. Operating Voltage
o
(RT=47kΩ, Ta=25 C)
o
(mA)
LIM
0.81
0.8
0.79
0.78
0
2
4
6
Operating Voltage V+ (V)
(RT=47kΩ, Ta=25 C)
900
800
Switching Current Limit I
B
Reference Voltage V (V)
0.82
700
600
500
400
8
0
Quiescent Current vs. Operating Voltage
L
(nA)
2
1.5
1
0.5
0
Ver.2010-04-14
0
2
4
6
Operating Voltage V+ (V)
8
(V
100
DD_STB
2.5
Standby Current I
(mA)
DD
Quiescent Current I
(R =47kΩ, R =Non Load, Ta=25 C)
T
2
4
6
Operating Voltage V+ (V)
8
Standby Current vs. Operating Voltage
o
3
8
o
ON/OFF
=0V, Ta=25 C)
10
1
0.1
0.01
0.001
0
2
4
6
Operating Voltage V+ (V)
8
-5-
NJU7691
■TYPICAL CHARACTERISTICS
Error Amplifier Block
Voltage Gain, Phase vs. Frequency
+
Phase
45
135
Gain
30
90
15
45
0
0.1
1
Output Block
Output Low Level ON Resistance
o
+
V =3.3V
V+=7V
1.2
0.8
0.4
0
Output High Level ON Resistance
ROH (Ω)
1
-6-
Output Low Level ON Resistance
ROL (Ω)
V+=2.2V
3
2.5
10
100
Switching Current ISW (mA)
V+=2.2V
+
2
V+=2.2V
V =3.3V
+
V =7V
1.5
1
0.5
0
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
+
1.6
V =3.3V
V+=7V
1.2
0.8
0.4
0
1
1000
Output Block
Output High Level ON Resistance
vs. Temperature (Isw=-200mA)
vs. Switching Current (Ta=25 C)
2
10
100
Switching Current I
(mA)
1000
SW
Output Low Level ON Resistance
ROL (Ω)
OH
Output High Level ON Resistance
(W)
R
o
vs. Switching Current (Ta=25 C)
1.6
0
10000
10
100
1000
Frequency f (kHz)
Output Block
Output High Level ON Resistance
2
180
Phase Φ (deg)
Voltage Gain Av (dB)
o
(V =3.3V, Gain=40dB, Ta=25 C)
60
3
2.5
2
Output Block
Output Low Level ON Resistance
vs. Temperature (Isw=+200mA)
V+=2.2V
V+=3.3V
+
V =7V
1.5
1
0.5
0
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
Ver.2010-04-14
NJU7691
■TYPICAL CHARACTERISTICS
Reference Voltage vs. Temperature
Soft Start Time vs. Temperature
(V+=3.3V)
(V+=3.3V, RT=47kΩ)
0.82
Reference Voltage V (V)
7
B
Soft Start Time Tss (ms)
8
6
5
4
3
2
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
0.81
0.8
0.79
0.78
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
760
(V+=3.3V, R =47kΩ)
T
740
720
700
680
660
640
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
Switching Current Limit ILIM (mA)
Oscillator Frequency f
OSC
(kHz)
Oscillator Frequency vs. Temperature
1000
900
800
700
600
500
V+=2.2V
400
V+=3.3V
300
V =7V
2.5
2
1.5
1
0.5
0
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
Ver.2010-04-14
2.1
Threshold Voltage (V)
High Side SW Leak Current ILEAKH (µA)
3
T
+
200
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
High Side SW Leak Current vs. Temperature
(V+=3.3V, VON/OFF =0V, R =47kΩ)
Switching Current Limit vs. Temperature
(RT=47kΩ)
Under Voltage Lockout Block
vs. Temperature
2.05
2
1.95
1.9
VT_ON
V
T_OFF
1.85
1.8
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
-7-
NJU7691
■TYPICAL CHARACTERISTICS
Standby Current vs. Temperature
1.5
1
0.5
0
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
10
(µA)
T
DD_STB
2
(V+=3.3V, R =47kΩ)
Standby Current I
Quiescent Current I
DD
(mA)
Quiescent Current vs. Temperature
(V+=3.3V, VON/OFF =0V)
1
0.1
0.01
0.001
0.0001
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (oC)
[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.
-8-
Ver.2010-04-14