NJM2340
HIGH PRECISION DC/DC CONVERTER CONTROL IC
■GENERAL
DESCRIPTION
NJM2340
is a high precision DC/DC converter control IC
with current sense amplifier.
It uses a low side current sensing which reduces external
components and improves accuracy.
It is applicable for a wide range of application since it
features high operating voltage and small outline packages.
■PACKAGE
OUTLINE
NJM2340M
NJM2340RB1
■FEATURES
●PWM
switching control
●Operating
Voltage
(3.6 to 32V)
●Wide
Oscillator Range
(20kHz to 500 kHz)
●Duty
Cycle
(0% to 100%)
●Current
Sensing Amplifier
●High
Precision Reference Voltage
Voltage Detect: 1V±1.5%
Current Detect: 150mV±4%
●Bipolar
Technology
●Package
Outline
DMP8, TVSP8
■PIN
CONFIGURATION
1
2
3
4
8
7
6
5
NJM2340M
NJM2340RB1
Pin Function
1.IN1
2.IN2
3.F.B
4.GND
5.OUT
6.CT
7.V
REF
8.V
+
Ver 2.0
- 1 -
NJM2340
■BLOCK
DIAGRAM
V
+
8
V
REF
7
CT
6
OUT
5
V
REF
OSC
ERROR AMP
1V
PWM
CURRENT
SENSE AMP
0.15V
1
IN1
2
IN2
3
F.B
4
GND
■ABSOLUTE
MAXIMUM RATINGS (Ta=25°C )
PARAMETER
SYMBOL
RATINGS
+
Maximum Supply Voltage
V
36
Output Sink Current
I
SINK
15
(DMP8)
300
Power Dissipation
P
D
(TVSP8) 320
Operating Temperature Range
Topr
-40
∼
+85
Storage Temperature Range
Tstg
-50
∼
+150
UNIT
V
mA
mW
°C
°C
■RECOMMENDED
OPERATING CONDITIONS (Ta=25°C)
PARAMETER
Supply Voltage
Oscillation Frequency
Oscillator Timing Resistance
SYMBOL
V
+
fosc
R
T
MIN.
3.6
20
20
MAX.
32
500
100
UNIT
V
kHz
kΩ
-2-
NJM2340
■ELECTRICAL
CHARACTERISTICS (V
+
=12V,Ta=25°C)
REFERENCE VOLTAGE BLOCK
PARAMETER
SYMBOL
TEST CONDITION
Output Voltage
Line Regulation
Load Regulation
OSCILLATOR BLOCK
PARAMETER
Oscillation Frequency
V
REF
L
INE
L
OAD
I
OR
=1mA
V
+
=3.6
∼
32V, I
OR
=1mA
I
OR
=0.1
∼
5.0mA
MIN.
1.98
–
–
TYP.
2.00
4.0
6.0
MAX.
2.02
20
40
UNIT
V
mV
mV
SYMBOL
f
OSC
TEST CONDITION
R
T
=27kΩ, C
T
=220pF
MIN.
315
TYP.
350
MAX.
385
UNIT
kHz
CURRENT SENSE AMPLIFIER BLOCK
PARAMETER
SYMBOL
Reference Voltage1
Input Bias Voltage1
Maximum Output Voltage1
(F.B Pin)
Maximum Source Current1
(F.B Pin)
ERROR AMPLIFIER BLOCK
PARAMETER
Reference Voltage2
Input Bias Voltage2
Maximum Output Voltage2
(F.B Pin)
Maximum Source Current2
(F.B Pin)
PWM COMPARATE BLOCK
PARAMETER
Input Threshold Voltage (F.B Pin)
Input Threshold Voltage (F.B Pin)
OUTPUT BLOCK
PARAMETER
L Output Voltage (OUT Pin)
GENERAL CHARACTERISTICS
PARAMETER
Average Quiescent Current
V
B
1
I
B
1
V
OM+
1
V
OM-
1
I
OM
1
TEST CONDITION
MIN.
144
–
–
0.6
40
TYP.
150
20
V
REF
-0.15
0.75
85
MAX.
156
100
–
0.9
200
UNIT
mV
nA
V
V
µA
R
NF
=100kΩ
R
NF
=100kΩ
V
OM
1=0.5V
SYMBOL
V
B
2
I
B
2
V
OM+
2
V
OM-
2
I
OM
2
TEST CONDITION
MIN.
0.985
–
–
0.6
40
TYP.
1.000
20
V
REF
-0.15
0.75
85
MAX.
1.015
100
–
0.9
200
UNIT
V
nA
V
V
µA
R
NF
=100kΩ
R
NF
=100kΩ
V
OM
2=0.5V
SYMBOL
V
TH0
V
TH100
TEST CONDITION
duty·cycle=0%
(note)
duty·cycle=100%
(note)
MIN.
V
OM
-
–
TYP.
1.0
1.4
MAX.
1.1
–
UNIT
V
V
SYMBOL
V
OL
TEST CONDITION
I
SINK
=10mA
MIN.
–
TYP.
0.5
MAX.
0.7
UNIT
V
SYMBOL
I
CCAV
TEST CONDITION
R
L
=∞, duty·cycle=50%
MIN.
–
TYP.
1.5
MAX.
2.0
UNIT
mA
(note) Duty·Cycle is defined as follows:
Duty·Cycle=0%: IC output transistor is OFF.
Duty·Cycle=100%: IC output transistor is ON.
-3-
NJM2340
■TYPICAL
APPLICATION
V
IN
Q1
R
T
27k
Ω
C
T
220pF
R
BE
V
+
L
V
OUT
R
BC
5
8
V
REF
7
CT
6
OUT
V
REF
OSC
ERROR AMP
1V
R2
PWM
CURRENT
SENSE AMP
C
IN
D1
C
OUT
0.15V
1
2
3
4
IN1
IN2
C
NF
2
F.B
R
NF
2
R
NF
1
GND
R1
GND
IN
C
NF
1
R
SC
R
CIN
GND
OUT
-4-
NJM2340
■TIPICAL
CHARACTERISTICS
Oscillator Frequency vs. Timing Resistor
(V
+
=12V,Ta=25°C)
C
T
=100pF
C
T
=220pF
Oscillator Frequency vs. Timing Capacitor
(V
+
=12V,Ta=25°C)
1000
1000
Oscillator Frequency
f
OSC
(kHz)
Osillator Frequency
f
OSC
(kHz)
R
T
=47kΩ
100
100
C
T
=1000pF
C
T
=4700pF
R
T
=20kΩ
10
10
Timing Resistor R
T
(kΩ)
Reference Voltage vs. Output Current
(V
+
=12V,Ta=25°C)
L Output Voltage V
OL
(V)
10
R
T
=100kΩ
10
100
1000
Timing Capacitor C
T
(pF)
L Output Voltage vs. Source Current
(V
+
=12V,Ta=25°C)
100
10000
Reference Voltage V
REF
(V)
2.5
2
1.5
1
0.5
0
0
0.8
0.6
0.4
0.2
0
5
10
15
20
25
30
0
3
6
9
12
15
Output Current I
OR
(mA)
Source Current I
SOURCE
(mA)
Average Quiescent Current
I
CC
(mA)
3
2.5
2
1.5
1
0.5
0
0
Average Quiescent Current
(R
L
=
∞
,duty·cycle=50%,Ta=25°C)
10
20
電源電圧
V
+
(V)
30
40
-5-
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