NJM2377
Ver 2.
0
- 1 -
SWITCHING REGULATOR CONTROL IC
■GENERAL DESCRIPTION ■PACKAGE OUTLINE
■FEATURES
● PWM switching control
● Operating Voltage (2.7 to 18V)
● Wide Oscillator Range (10 to 500 kHz)
● ON/OFF Maximum Duty Cycle (Ton:Toff = 9:1)
● Totem Pole Output
● Soft-Start Function
● UVLO (Under Voltage Lockout)
● Bipolar Technology
● Package Outline DIP8, DMP8, SSOP8, VSP8
■BLOCK DIAGRAM
The NJM2377 is a high speed low voltage operation
switching regulator control IC.
It features a totem pole driver circuit that can directly drive
an external Bipolar transistor.
The NJM2377 is suitable for potable applications, including
TFT panel supply with fly-back configuration.
NJM2377D
NJM2377V
NJM2377M
NJM2377R
1. IN
-
2. F.B
3. GND
4. OUT
5. V
+
6. CS
7. CT
8. REF
PIN FUNCTION
1
V
REF
ER·AMP
L.O
U.V.LO
OSC
PWM
8 7 6 5
4 3 2
0.52V
S.C.P
30uA
IN
-
F. B GN D O U T
V
+
CS CT REF
NJM2377
- 2 -
■ABSOLUTE MAXIMUM RATINGS (Ta=25°C)
PARAMETER SYMBOL MAXIMUM RATINGS UNIT
Input Voltage V
+
18 V
Output Current I
O
±50 mA
Power Dissipation
P
D
(DIP 8) 700
(DMP 8) 300
(SSOP 8) 250
(VSP 8) 320
mW
Operating Temperature Range T
OPR
-40 ∼ +85 °C
Storage Temperature Range T
STG
-50 ∼ +125 °C
■RECOMEND OPERATING CONDITIONS (V
+
=3V, Ta=25°C)
PARAMETER SYMBOL MIN. MAX. UNIT
Operating Voltage V
+
2.7 18 V
Feed Back Resistor R
NF
100 – kΩ
Oscillator Timing Capacitor C
T
220 22,000 pF
Oscillator Timing Resistor R
T
5 100 kΩ
Oscillation Frequency f
OSC
10 500 kHz
NJM2377
-
3
-
■ELECTRICAL CHARACTERISTICS (V
+
=3V,R
T
=39kΩ,C
T
=470pF,Ta=25°C)
REFERENCE VOLTAGE BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Output Voltage V
REF
I
OR
=1mA 1.47 1.50 1.53 V
Line Regulation ∆V
O
-V
IN
V
+
=2.7 ∼ 18V, I
OR
=1mA – 3.8 11.5 mV
Load Regulation ∆V
O
-I
O
I
OR
=0.1 ∼ 5.0mA – 5 30 mV
OSCILLATOR BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Oscillation Frequency f
OSC
R
T
=39kΩ, C
T
=470pF 80 100 120 kHz
Oscillate Fluctuations1
(Line Fluctuations)
f
dV
V
+
=2.7 ∼ 18V – 1 – %
Oscillate Fluctuations2
(Temp Fluctuations)
f
dT
Ta=-40°C ∼ +85°C – 5 – %
ERROR AMPLIFIER BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Reference Voltage V
B
0.51 0.52 0.53 V
Input Bias Voltage I
B
– 5 100 nA
Open Loop Gain A
V
– 90 – dB
Gain Bandwidth Product G
B
– 1.0 – MHz
Maximum Output Voltage
(F.B Pin)
V
OM+
R
NF
=100kΩ, IN
-
Pin=0V 1.9 2.2 2.4 V
V
OM-
R
NF
=100kΩ, IN
-
Pin=0V – – 200 mV
Output Source Current
(F.B Pin)
I
OM+
V
OM
=1V, IN
-
Pin=0V 40 85 200 µA
PWM COMPARATE BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Input Threshold Voltage
(F.B Pin)
V
TH0
duty·cycle=0% – 0.45 0.65 V
Input Threshold Voltage
(F.B Pin)
V
TH80
duty·cycle=80% – 1.05 – V
Maximum Duty Cycle αM F.B Pin=1.2V
R
T
=39kΩ, C
T
=470pF
80 90 – %
SOFT START CIRCUIT BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Input Bias Current
(CS Pin)
I
BCS
– 250 650 nA
Input Threshold Voltage
(CS Pin)
V
THCS0
duty·cycle=0%, F.B Pin=1.2V – 0.25 0.35 V
Input Threshold Voltage
(CS Pin)
V
THCS80
duty·cycle=80%, F.B Pin=1.2V – 0.79 – V
NJM2377
- 4 -
■ELECTRICAL CHARACTERISTICS (V
+
=3V,R
T
=39kΩ,C
T
=470pF,Ta=25°C)
SHORT CIRCUIT PROTECTION
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Input Threshold Voltage
(F.B Pin)
V
THPC
1.30 1.50 1.80 V
Charge Current (CS Pin) I
CHG
CS Pin=0V, F.B Pin=2V 10 30 50 µA
Latch Mode Threshold
Voltage (CS Pin)
V
THLA
1.20 1.50 1.80 V
UNDER VOLTAGE LOCKOUT
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
ON Threshold Voltage V
THON
– 1.95 – V
OFF Threshold Voltage V
THOFF
– 1.78 – V
Hysteresis Voltage V
HYS
60 170 – mV
OUTPUT BLOCK
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
H-Output Voltage (OUT Pin) V
OH
R
L
=10kΩ 1.7 2.0 – V
L-Output Voltage (OUT Pin) V
OL
Output Sink Current=20mA – 0.25 0.65 V
Output Source Current
(OUT Pin)
I
SOURCE
Out Pin=0V 23 35 – mA
GENERAL CHARACTERISTICS
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Quiescent Current I
CCLA
Latch Mode, CS Pin=1.8V – 1.7 2.4 mA
Average Quiescent Current I
CCAV
R
L
= , duty·cycle=50% – 5.0 6.8 mA
NJM2377
-
5
-
■ TYPICAL APPLICATIONS
Rt
GND
V
+
V
OUT
Rsf Rsr Cs
Ct
1
V
REF
ER·AMP
L.O
U.V.LO
OSC
PWM
8 7 6 5
4 3 2
0.52V
S.C.P
30uA
GND
C
IN
Q1
Rf
C
LP
R2
D1
R1
C
OUT
VR1
N2 N1
NJM2377
-
6
-
■TIPICAL CHARACTERISTICS
Oscillator Frequency vs. Timing Resistor
(V
+
=3V,Ta=25°C)
1
10
100
1000
1 10 100 1000 10000
Timing Resistor R
T
(kΩ)
Oscillator Frequency
f
OSC
(kHz)
C
T
=470pF
C
T
=1000pF
Oscillator Frequency vs. Timing Capacitor
(V
+
=3V,Ta=25°C)
1
10
100
1000
10 100 1000 10000 100000
Timing Capacitor C
T
(pF)
Oscillator Frequency
f
OSC
(kHz)
R
T
=10kΩ
R
T
=100kΩ
R
T
=33kΩ
Operating Current vs. Operating Voltage
(Ta=25°C)
0
1
2
3
4
5
6
0 5 10 15 20
Operating Voltage V
+
(V)
Operating Current I
CC
(mA)
I
CCAV
I
CCLA
H Output Voltage(OUT Pin) vs. Source Current
(V
+
=3V,CT=0V,CS=1V,Ta=25°C)
0
0.5
1
1.5
2
2.5
3
010203040
Source Current I
SOURCE
(mA)
H Output Voltage V
OH
(V)
L Output Voltage(OUT Pin) vs. Sink Current
(V
+
=3V,CS=FB=0V,CT=0.5V,Ta=25°C)
0
0.2
0.4
0.6
0.8
1
1.2
0 102030405060
Sink Current I
SINK
(mA)
L Output Voltage V
OL
(V)
Reference Voltage vs. Output Current
(V
+
=3V,Ta=25°C)
1.42
1.44
1.46
1.48
1.5
1.52
051015
Output Current I
OR
(mA)
Reference Voltage V
REF
(V)
NJM2377
-7 -
■TIPICAL CHARACTERISTICS
Maximum Duty Cycle vs. Oscillator Frequency
(V
+
=3V,Ta=25°C)
0
10
20
30
40
50
60
70
80
90
100
10 100 1000 10000
Oscillator Frequency f
OSC
(kHz)
Maximum Duty Cycle
αM (%)
Duty Cycle vs. CS Pin Voltage
(V
+
=3V,Ta=25°C)
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
CS Pin Voltage (V)
Duty Cycle α (%)
Quiescent Current(Latch Mode) vs.Temperature
(V
+
=3V,CS=1.8V)
0
0.5
1
1.5
2
2.5
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Quiescent Current
(Latch Mode) I
CCLA
(mA)
Average Quiescent Current vs. Temperature
(V
+
=3V,R
L
= ,duty·cycle=50%
R
T
=39kΩ,C
T
=470pF)
0
1
2
3
4
5
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Average Quiescent Current
I
CCAV
(mA)
∞
NJM2377
-
8
-
■TIPICAL CHARACTERISTICS
Reference Voltage Block
Reference Voltage vs. Temperature
(V
+
=3V,I
OR
=1mA)
1.44
1.46
1.48
1.5
1.52
1.54
1.56
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Reference Voltage V
REF
(V)
Oscillator Frequency vs. Temperature
(V
+
=3V,R
T
=39kΩ,C
T
=470pF)
80
90
100
110
120
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Oscillator Frequency f
OSC
(kHz)
Error Amplifire Block
Reference Voltage vs. Temperaure
(V
+
=3V)
0.5
0.51
0.52
0.53
0.54
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Error Amplifire Block
Reference Voltage V
B
(V)
Maximum Duty Cycle vs. Temperature
(V
+
=3V,R
T
=39kΩ,C
T
=470pF)
80
85
90
95
100
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Maximum Duty Cycle
α (%)
Charge Current (CS Pin) vs. Temperature
(V
+
=3V,F.B Pin=2V)
20
25
30
35
40
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Charge Current I
CHG
(uA)
Under Voltage Lockout Block
ON/OFF Threshold Voltage vs. Temperature
1
1.5
2
2.5
3
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Operating Voltage V
+
(V)
V
THON
V
THOFF
NJM2377
-
9
-
■TIPICAL CHARACTERISTICS
[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.
H Output Voltage (OUT Pin) vs. Temperature
(V
+
=3V,R
L
=10kΩ)
0
0.5
1
1.5
2
2.5
3
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
H Output Voltage V
OH
(V)
L Output Voltage (OUT Pin) vs. Temperature
(V
+
=3V,I
SINK
=20mA)
0
20
40
60
80
100
120
140
160
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
L Output Voltage V
OL
(mV)
Output Source Current (OUT Pin) vs.
Temperature (V
+
=3V,OUT Pin=0V)
0
5
10
15
20
25
30
35
40
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (°C)
Output Source Current
I
SOURCE
(mA)
