NJM2309
-
1
-
Ver.2011-12-08
Switching Regulator Control IC for Step-Down
■GENERAL DESCRIPTION ■PACKAGE OUTLINE
■FEATURES
● PWM switching control
● Operating Voltage 3.6V to 32V
● Wide Oscillator Range 5kHz to 500 kHz
● Duty Cycle 0% to 100%
● Soft Start function
● Timer Latch for Short Circuit Protection
● Under Voltage Lockouts (U.V.LO)
● Bipolar Technology
● Package Outline NJM2309M : DMP8
NJM2309E : SOP8 JEDEC 150mil
NJM2309V : SSOP8
■BLOCK DIAGRAM
1
VREF
V+
ER⋅AMP
L.O
U.V.LO
OSC
PW M
8 7 6 5
432
CSCTREF
IN- OUTGNDF. B
0.52V
S.C.P
30
µ
A
The NJM2309 is a step-down Switching regulator IC with a
wide operating voltage range.
It features an open collector driver that can provide step-down
applications.
Internal soft-start function and timer latch function for shor
t
circuit protection are included, requiring no external
components.
1. IN -
2. F.B
3. GND
4. OUT
5. V +
6. CS
7. CT
8. REF
PIN FUNCTION
NJM2309E
( SOP8 )
NJM2309M
( DMP8 )
NJM2309V
( SSOP8 )
NJM2309
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2
-Ver.2011-12-08
■ABSOLUTE MAXIMUM RATINGS (Ta=25°C)
PARAMETER SYMBOL MAXIMUM RATINGS UNIT
Input Voltage V+ 36 V
Out pin Voltage VO_PIN 36 V
Reference Output Current IOR 10 mA
Output Current IO 200 mA
Power Dissipation PD
DMP8
SOP8
SSOP8
: 375
: 375
: 312
mW
Operating Temperature Range Topr -40 ~ +85 °C
Storage Temperature Range Tstg -50 ~ 150 °C
■RECOMMENDED OPERATING CONDITIONS (V+=6V, Ta=25°C)
PARAMETER SYMBOL MIN. MAX. UNIT
Operating Voltage V+ 3.6 32 V
OUT pin Voltage VO_PIN – 32 V
Feed Back Resistor RNF 100 – kΩ
Oscillator Timing Capacitor CT 220 22,000 pF
Oscillator Timing Resistor RT 10 100
kΩ
Oscillation Frequency fOSC 5 500 kHz
■ELECTRICAL CHARACTERISTICS (V+=6V, RT=33kΩ, CT=1,000pF, Ta=25°C)
REFERENCE VOLTAGE BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Output Voltage VREF I
OR=1mA 2.45 2.50 2.55 V
Line Regulation LINE V
+=3.6V ~ 32V, IOR=1mA – 6.8 20.7 mV
Load Regulation LOAD IOR=0.1mA ~ 5.0mA – 5 30 mV
OSCILLATOR BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Oscillation Frequency fosc CT=1,000pF, RT=33kΩ 85 105 125 kHz
Oscillate Fluctuations1
(Line Fluctuations) fdv V
+=3.6V to 32V – 1 – %
Oscillate Fluctuations2
(Temp Fluctuations) fdt Ta =-40 °C to +85°C – 5 – %
ERROR AMPLIFIER BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Reference Voltage VB 0.51 0.52 0.53 V
Input Bias Current IB – 5 100 nA
Open Loop Gain AV – 90 – dB
Gain Band width Product GB – 0.6 – MHz
VOM+ RNF=100kΩ VREF-0.2 – – V
Maximum Output Voltage
(F.B Pin) VOM- RNF=100kΩ – – 200 mV
Output Source Current
(F.B Pin) IOM+ V
OM=1V 40 85 200
µA
NJM2309
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3
-
Ver.2011-12-08
■ELECTRICAL CHARACTERISTICS (V+=6V, RT=33kΩ, CT=1,000pF, Ta=25°C)
PWM COMPARATE BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Input Threshold Voltage
(F.B Pin)
VTH0 duty·cycle=0%* – 0.40 0.50 V
Input Threshold Voltage
(F.B Pin) VTH100 duty·cycle=100%* – 0.85 – V
SOFT START CIRCUIT BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Input Bias Current (CS Pin) IBCS – 250 650 nA
Input Threshold Voltage
(CS Pin) VTHCS0 duty·cycle=0%* – 0.25 0.35 V
Input Threshold Voltage
(CS Pin) VTHCS100 duty·cycle=100%* – 0.7 – V
SHORT CIRCUIT PROTECTION BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Input Threshold Voltage
(F.B Pin) VTHPC 1.20 1.50 1.80 V
Charge Current (CS Pin) ICHG CS Pin=0V, F.B Pin=2V 10 30 50 µA
Latch mode Threshold Voltage
(CS Pin) VTHLA 1.20 1.50 1.80 V
UNDER VOLTAGE LOCKOUT BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
ON Threshold Voltage VTHON – 2.70 – V
OFF Threshold Voltage VTHOFF – 2.52 – V
Hysteresis Voltage VHYS 60 180 – mV
OUTPUT BLOCK
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
L Level Output Voltage
(OUT Pin)
VOL Output Sink Current =70mA – 0.35 0.75 V
Leak Current IO_LEAK V
+=32V, VO_PIN=32V – – 1
µA
GENERAL CHARACTERISTICS
PARAMETER SYMBOL RATINGS MIN. TYP. MAX. UNIT
Quiescent Current ICCLA Latch Mode – 1.6 2.2 mA
Average Quiescent Current ICCAV R
L= ∞, duty·cycle=50% – 5.5 10 mA
(*) Duty·Cycle is defined as follows:
Duty·Cycle=0%: IC output transistor is OFF.
Duty·Cycle=100%: IC output transistor is ON.
NJM2309
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4
-Ver.2011-12-08
■ TYPICAL APPLICA TIONS
RT
GND
V
+
VOUT
Rsf Rsr Cs
CT
1
VREF
ER⋅AMP
L.O
U.V.LO
OSC
PWM
8 7 6 5
43 2
0.52V
S.C.P
30uA
GND
CIN
Q1
RNF C
NF
R2
D1
R1
COUT
L
Rbe
Rbc
NJM2309
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5
-
Ver.2011-12-08
■TYPICAL C HARACTERISTICS
0
0.4
0.8
1.2
1.6
2
0 40 80 120 160 200
L Level Output Voltage vs. Sink Current
(V+=6V, duty cycle=100%, Ta=25
oC)
Sink Current I
SINK (mA)
L Level Output Voltage VOL (V)
0
20
40
60
80
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Duty Cycle vs. CS Pin Voltage
(V+=6V, F.B pin=1.2V, Ta=25
oC)
CS Pin Voltage V
THCS (V)
Duty Cycle α (%)
10
100
1000
10 100
Oscillator Frequency vs. Timing Resistor
(V+=6V, Ta=25oC)
Timing Resistor R
T (kΩ)
Oscillator Frequency fOSC (kHz)
CT=220pF
CT=470pF
CT=1,000pF
CT=3,300pF
1
10
100
1000
100 1000 10000 100000
RT=33kΩ
Oscillator Frequency fOSC (kHz)
Oscillator Frequency vs. Timing Capacitor
(V+=6V, Ta=25oC)
Timing Capacitor C
T (pF)
RT=100kΩ
RT=10kΩ
2.48
2.49
2.5
2.51
2.52
0 10203040
Reference Voltage vs. Operating Voltage
(IOR=1mA, Ta=25oC)
Operating Voltage V
+ (V)
Reference Voltage VREF (V)
0
2
4
6
8
10
0 10203040
Operating Current vs. Operating Voltage
(Ta=25oC)
Operating Voltage V
+ (V)
Operating Current ICC (mA)
ICCAV
ICCLA
NJM2309
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6
-Ver.2011-12-08
■TYPICAL C HARACTERISTICS
(V+=6V, Gain=40dB, Ta=25
oC)
0
15
30
45
60
0
45
90
135
180
0.1 1 10 100 1000
Error Amplifier Block
Voltage Gain, Phase vs. Frequency
Phase Φ (deg)
Frequency f (kHz)
Voltage Gain Av (dB)
Phase
Gain
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (
oC)
L Level Output Voltage VOL (V)
L Level Output Voltage vs. Temperature
(V+=6V, ISINK=70mA)
85
90
95
100
105
110
115
120
125
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (
oC)
Oscillator Frequency fOSC (kHz)
Oscillator Frequency vs. Temperature
(V+=6V, RT=33kΩ, CT=1,000pF)
2.44
2.46
2.48
2.5
2.52
2.54
2.56
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (
oC)
Referece Voltage VREF (V)
Referece Voltage vs. Temperature
(V+=6V, IOR=1mA)
0
2
4
6
8
10
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (
oC)
Average Quiescent Current
ICCAV (mA)
Average Quiescent Current vs. Temperature
(V+=6V, RL= , duty cycle=50%, R
T=33kΩ, CT=1,000pF)
1
1.2
1.4
1.6
1.8
2
-50 -25 0 25 50 75 100 125 150
Ambient Temperature Ta (
oC)
Quiescent Current
ICCLA (mA)
Quiescent Current vs. Temperature
(Latch Mode, V+=6V, RT=33kΩ, CT=1,000pF)
∞
NJM2309
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7
-
Ver.2011-12-08
MEMO
[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.
