NJM2374AM - NJR - Product.Network

NJM2374

A

-

1

-

Ver.2007-06-08

PWM DC/DC CONVERTER IC

■GENERAL DESCRIPTION ■PACKAGE OUTLINE

■FEATURES

●Operating Voltage (2.5V* to 40V)

●NJM2374AE Operating Voltage (2.5V* to 48V)

●Wide Oscillator Frequency (100Hz to 100kHz)

●Internal High Power Transistor 1.5A (max.)

●Internal Over Current Limit Circuit

●PWM form Switching Power Supply Control

●Bipolar Technology

●Package Outline DIP8, DMP8, EMP8, SSOP14

*Ta =25°C. At low temperature, the minimum voltage is 3.0V.

■PIN CONFIGURATION

The NJM2374A is a PWM DC/DC converter IC.

It features fixed frequency type PWM control for better noise

handling and to avoid intermittent oscillation observed in a

simplified controller.

It is suitable for Step-Up, Step-Down and Inverting applications

for EMI sensitive application.

NJM2374AD

NJM2374AM

NJM2374AE

1.CS

2.ES

3.CT

4.GND

5.IN+

6.V+

7.SI

8.CD

PIN FUNCTION

1.CS

2.NC

3.ES

4.NC

5.CT

6.NC

7.GND

8.IN+

9.NC

10.V+

11.NC

12.SI

13.NC

14.CD

PIN FUNCTION

NJM2374AV

1

4

3

2

8

5

6

7

1

4

3

2

5

7

6

14

11

12

13

10

8

9

NJM2374AD NJM2374AM

NJM2374AE NJM2374AV

NJM2374A

-

2

-Ver.2007-06-08

■BLOCK DIAGRAM

1

1.5A

Maximum

ON duty 9:1

OSC BLOCK

4

3

2

8

5

6

7

V+

ES

GND

PWM

Logic

R

SQ

Vref

1.25V

±2%

CD

CT

CS

SI

IN+

Vth=300mV

Ipk Sense

PWM COMP

ERR.AMP

160Ω

(DIP8, DMP8, EMP8: PACKAGE)

1

1.5A

7

5

3

14

8

10

12

V+

ES

GND

R

SQ

Vref

1.25V

±2%

CD

CT

CS

SI

IN+

Vth=300mV

Ipk Sense

PWM COMP

ERR.AMP

2

NC

4

NC

6

NC 9NC

11 NC

13 NC

160Ω

Maximum

ON duty 9:1

OSC BLOCK

PWM

Logic

(SSOP14: PACKAGE)

NJM2374

A

-

3

-

Ver.2007-06-08

■ABSOLUTE MAXIMUM RATINGS (Ta=25°C )

PARAMETER SYMBOL RATINGS UNIT

Maximum Supply Voltage V+ 40

(NJM2374AE: 48V) V

Output Switch Current ISW 1.5 A

Output Switch Voltage VSW 40

(NJM2374AE: 48V) V

Comparator Input Voltage VIR -0.3 ~ 40

(NJM2374AE: 48V) V

Power Dissipation

PD

(DIP8) 875

(DMP8) 750 (note1)

(EMP8) 1,000 (note1)

(SSOP14) 375

mW

Operating Temperature Range Topr -40 ~ +85 °C

Storage Temperature Range Tstg -50 ~ +150 °C

(note1) At on PC board.

In the case of Step-Down and Inverting Conversion with the internal power transistor,

the Output Voltage must be set lower than 6V(-6V).

■POWER DISSIPATION vs. AMBIENT TEMPERATURE

In the case of SSOP packaging, the power dissipation should carefully

be considered when designing this parts.

0

200

400

600

800

1000

1200

25 50 75 100

Ambient Temperature Ta (°C)

Power Dissipation PD (mW)

NJM2374AM

A

t on PC board

NJM2374AD

NJM2374AV

NJM2374AE

A

t on PC board

(Topr=-40 to +85°C,Tj= to +150°C)

NJM2374A

-

4

-Ver.2007-06-08

■ELECTRICAL CHARACTERISTICS

DC Characteristics (V+=5V, Ta=25°C)

PARAMETER SYMBOL TEST CONDITIONS MIN. TYP. MAX. UNIT

Operating Current 1 ICC1 C

T=1nF, SI=V+, IN+> Vth, ES=GND – 2.8 4.0 mA

Operating Current 2

(NJM2374AE Only)

ICC2 V

+=48V, CT=1nF, SI=V+,

IN+> Vth, ES=GND

– 3.4 4.5 mA

Charge Current Ichg 12 20 30 µA

Discharge Current Idis 110 180 300 µA

Voltage Swing VOSC – 0.5 – VP-P

Discharge to Charge

Current Ratio

Iratio S

I=V+ – 9 – –

Peak Current

Sense Voltage

Vipk I

chg=Idis 250 300 350 mV

Saturation Voltage 1 Vsat1 Darlington Connection

(CS=CD), ISW=0.7A

– 1.0 1.3 V

Saturation Voltage 2 Vsat2 I

SW=0.7A, Ic(driver)=50mA

(Forced β≈14)

– 0.5 0.7 V

Output Transistor

Bias Resistance

Rbias – 160 – Ω

DC Voltage Gain hFE I

SW=0.7A, VCE=5.0V 35 120 – –

Collector Off-State

Current

IC(Off) V

CE=40V

(NJM2374AE: VCE=48V)

– 10 – nA

Threshold Voltage Vth 1.225 1.250 1.275 V

Input Bias Current IIB IN+=0V – 40 400 nA

(note) Output switch tests are performed under pulsed conditions to minimize power dissipation.

■TIMING CHART

Oscillator

Waveform

Reference

Voltage

Output

Voltage

Collector-Emitter

Voltage

High Voltage

Detect

Current-Limit

Active Point

OFF

ON

OSC Block to

FF Reset

HIGH

LOW

NJM2374

A

-

5

-

Ver.2007-06-08

■TIPICAL CHARACTERISTICS

Operating Current vs. Operating Voltage

(CT=1nF,SI=V+,IN+>Vth,ES=GND,Ta=25°C)

0

1

2

3

4

0 5 10 15 20 25 30 35 40

Operating Voltage V+ (V)

Operating Current ICC (mA)

Oscillator Frequency vs. Timing Capacitor

(V+=5V,SI=V+,Pin5=GND,Ta=25°C)

1

10

100

1000

100 1000 10000

Timing Capacitor CT (pF)

Oscillator Frequency

fOSC (kHz)

Saturation Voltage 1 vs. Collector Current

(V+=5V,CS=CD,Ta=25°C)

0

0.5

1

1.5

2

0 0.5 1 1.5 2

Collector Current IC (A)

Saturation Voltage 1 Vsat1 (V)

Switch ON/OFF Time vs. Timing Capacitor

(V+=5V,SI=V+,Pin5=GND,Ta=25°C)

1

10

100

1000

100 1000 10000

Timing Capacitor CT (pF)

Switch ON/OFF Time

tON / tOFF (µS)

tON

tOFF

Saturation Voltage 2 vs. Collector Current

(V+=5V,Ic(driver)=50mA,β=14,Ta=25°C)

0

0.5

1

1.5

2

00.511.52

Collector Current IC (A)

Saturation Voltage 2 Vsat2 (V)

NJM2374A

-

6

-Ver.2007-06-08

■TIPICAL CHARACTERISTICS

Saturation Voltage 2 vs. Temperature

(V+=5V,ISW=0.7A,Ic(driver)=50mA,β=14)

0

0.2

0.4

0.6

0.8

-50 -25 0 25 50 75 100 125 150

Ambient Temperature Ta (°C)

Saturation Voltage 2 Vsat2 (V)

Discharge to Charge Current Ratio vs.

Temperature (V+=5V,SI=V+)

6

7

8

9

10

-50 -25 0 25 50 75 100 125 150

Ambient Temperature Ta (°C)

Discharge to Charge Current

Ratio Iratio

Saturation Voltage 1 vs. Temperature

(V+=5V,CS=CD,ISW=0.7A)

0.6

0.7

0.8

0.9

1

1.1

1.2

-50 -25 0 25 50 75 100 125 150

Ambient Temperature Ta (°C)

Saturation Voltage 1 Vsat1 (V)

Operating Current vs. Temperature

(V+=5V,CT=1nF,SI=V+,IN+>Vth,ES=GND)

0

1

2

3

4

5

-50 -25 0 25 50 75 100 125 150

Ambient Temperature Ta (°C)

Operating Current ICC

(mA)

Threshold Voltage vs. Temperature

(V+=5V)

1.22

1.24

1.26

1.28

1.3

-50 -25 0 25 50 75 100 125 150

Ambient Temperature Ta (°C)

Threshold Voltage Vth (V)

NJM2374

A

-

7

-

Ver.2007-06-08

■TYPICAL APPLICATIONS

Step-Down Converter

1

NJM2374A

43

2

CT

470pF

8

6

7

D1

R2 3.6kΩ

L1 220µH

5

R1

1.2kΩ

RSC

0.22Ω

CIN

100µF

COUT

470µF

VIN=25V

VOUT=5V

In the case of Step-Down Conversion with the internal power transistor,

the Output Voltage must be set lower than 6V.

Step-Up Converter

1

NJM2374A

43

2

RC

180Ω

CT

1500pF

8

6

7

D1

R2

46kΩ

L1 180µH

5

R1

2kΩ

RSC

0.22Ω

CIN

100µF

COUT

150µF

VIN=14V VOUT=30V

Inverting Converter

1

NJM2374A

43

2

CT

680pF

8

6

7

D1

R2 1.2kΩ

L1

100µH

5

R1

3.6kΩ

RSC

0.22Ω

CIN

100µF

COUT

1000µF

VIN=5V

VOUT=-5V

In the case of Inverting Conversion with the internal power transistor,

the Output Voltage must be set lower than -6V.

D1 use to schottky diode.

In the case of SSOP packaging, the power dissipation should carefully

be considered when designing this parts.

NJM2374A

-

8

-Ver.2007-06-08

Step-Down Converter (High Current)

Step-Up Converter (High Current)

D1 use to schottky diode.

[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.

1

NJM2374A

4 3

2

CT

330pF

8

6

7

D1

R2 70kΩ

L1 33µF

5

R1

10kΩ

RSC

0.05Ω

CIN

300µF

COUT

300µF

VIN=20V

VOUT=10V

RBE

75Ω

RBC

300Ω

2SA1010

1

NJM2374A

4 3

2

RC2

680Ω

CT

330pF

8

6

7

D1

R2

46kΩ

L1 22µH

5

R1

10kΩ

RSC

0.075Ω

CIN

940µF

COUT

940µF

VIN=5V VOUT=7V

RC1

100Ω

2SC3255

RBE

220Ω