NJU7691RB1 - New Japan Radio Co., Ltd.

NJU7691

-

1

-

Ver.2012-08-03

300mA Synchronous Step-Down switching regulator IC

■ GENERAL DESCRIPTION ■ PACKAGE OUTLINE

■ 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 : MSOP8 (TVSP8)*

*MEET JEDEC MO-187-DA / THIN TYPE

■ PIN CONFIGURATION

The NJU7691 is a synchronous rectification switching

regulator IC with a power MOSFET (300mA output).

It incorporates an over-current detection and thermal

shutdown circuit, which can make a power supply circuit with

few external parts. The output voltage can be set from 1.8V.

Therefore it is suitable for a power supply circuit for digital chips

and logic ICs. The NJU7691 is available in a small and thin

8-lead MSOP (TVSP) package.

PIN FUNCTION

1. SW

2. V+

3. FB

4. IN-

5. ON/OFF

6. RT

7. AGND

8. PGND

NJU7691RB1

1 8

2 7

3 6

4 5

NJU7691RB1

(MSOP8 (TVSP8))

NJU7691

-

2

-Ver.2012-08-03

■ BLOCK DIAGRAM

Buffer

0.5V

OSC

UVLO Soft Start

Vref 0.8V

0.8V

0.2V

SW

PGND

RT

IN-

FB

V

+

PWM

ER⋅AMP

A

GND

OCP

Standby

ON/OFF

High: ON

Low : OFF (Standby)

TSD

100kΩ

NJU7691

-

3

-

Ver.2012-08-03

■ ABSOLUTE MAXIMUM RATINGS (Ta=25°C)

PARAMETER SYMBOL MAXIMUM RATINGS UNIT

Supply Voltage V+ +8 V

ON/OFF pin Voltage VON/OFF +8 V

Power Dissipation PD 580 (*1) mW

Operating Temperature Range Topr -40 to +85 °C

Storage Temperature Range Tstg -40 to +150 °C

(*1): Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 2-Layers)

■ RECOMMENDED OPERATING CONDITIONS

PARAMETER SYMBOL MIN. TYP. MAX. UNIT

Operating Voltage V+ 2.2 – 7 V

Output Current (*2) IOUT – – 300 mA

Oscillator Timing Resistor RT 30 47 120

kΩ

Oscillation Frequency fOSC 300 700 1,000 kHz

(*2): Steady Operating

■ ELECTRICAL CHARACTERISTICS (V

+=VON/OFF=3.3V, RT=47kΩ, Ta=25°C)

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT

Under Voltage Lockout Block

ON Threshold Voltage VT_ON V

+= L → H 1.9 2.0 2.1 V

OFF Threshold Voltage VT_OFF V

+= H → L 1.8 1.9 2.0 V

Hysteresis Voltage VHYS 60 100 – mV

Soft Start Block

Soft Start Time TSS V

T_ON → Duty=80% 2 4 8 ms

Oscillator Block

Oscillation Frequency fOSC 630 700 770 kHz

Oscillate Supply Voltage

Fluctuations fDV V

+=2.2V to 7V – 1 – %

Oscillate Temperature

Fluctuations fDT Ta=-40 °C to +85°C – 3 – %

Error Amplifier Block

Reference Voltage VB -1.0% 0.8 +1.0% V

Input Bias Current IB -0.1 – 0.1

µA

Open Loop Gain AV – 80 – dB

Gain Bandwidth Product GB – 1 – MHz

Output Source Current IOM+ V

FB=1V, VIN-=0.7V 20 35 50

µA

Output Sink Current IOM- V

FB=1V, VIN-=0.9V 1 2.5 5 mA

NJU7691

-

4

-Ver.2012-08-03

■ ELECTRICAL CHARACTERISTICS (V

+=VON/OFF=3.3V, RT=47kΩ, Ta=25°C)

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT

PWM Comparate Block

VT_0 Duty=0% 0.16 0.22 0.28 V

Input Threshold Voltage VT_50 Duty=50% 0.44 0.50 0.56 V

Maximum Duty Cycle MAXDUTY V

FB=0.9V 100 – – %

Output Block

Output High Level

ON Resistance ROH I

SW=-200mA – 0.9 1.2

Ω

Output Low Level

ON Resistance ROL I

SW=+200mA – 0.8 1.1

Ω

Switching Current Limit ILIM 500 650 800 mA

High Side SW Leak Current ILEAKH V

ON/OFF=0V – – 1

µA

Output Pull-Down Resistance RPD-SW 60 100 140 kΩ

ON/OFF Block

ON Control Voltage VON V

ON/OFF= L → H 1.6 – V+ V

OFF Control Voltage VOFF V

ON/OFF= H → L 0 – 0.3 V

General Characteristics

Quiescent Current IDD R

L=Non Load – 1.3 1.6 mA

Standby Current IDD_STB V

ON/OFF=0V – – 5

µA

■ TYPICAL APPLICATIONS

ON/

OFF

VIN

VOUT

1 2 3 4

5 6 7 8

IN- FB V

+

RT

A

GND PGND

SW

RT

COUT

CIN

R2

R1

CNF

RNF

L

NJU7691

CFB

RFB

ON/OFF

High: ON

Low: OFF

(Standby)

SBD

NJU7691

-

5

-

Ver.2012-08-03

■ TYPICAL CHARACTERISTICS

100

1000

10 100

Oscillation Frequency fOSC (kHz)

Oscillation Frequency vs. Timing Resistance

(V+=3.3V, Ta=25oC)

Timing Resistance R

T (kΩ)

660

680

700

720

740

02468

Oscillation Frequency fosc (kHz)

Operating Voltage V+ (V)

Oscillation Frequency vs. Operating Voltage

(RT=47kΩ, Ta=25oC)

0.78

0.79

0.8

0.81

0.82

02468

Reference Voltage VB (V)

Operating Voltage V+ (V)

Reference Voltage vs. Operating Voltage

(RT=47kΩ, Ta=25oC)

400

500

600

700

800

900

02468

Switching Current Limit ILIM (mA)

Operating Voltage V+ (V)

Switching Current Limit vs. Operating Voltage

(RT=47kΩ, Ta=25oC)

0

0.5

1

1.5

2

2.5

3

02468

Quiescent Current IDD (mA)

Operating Voltage V+ (V)

Quiescent Current vs. Operating Voltage

(RT=47kΩ, RL=Non Load, Ta=25oC)

0.001

0.01

0.1

1

10

100

02468

Standby Current IDD_STB (nA)

Operating Voltage V+ (V)

Standby Current vs. Operating Voltage

(VON/OFF=0V, Ta=25oC)

NJU7691

-

6

-Ver.2012-08-03

■ TYPICAL CHARACTERISTICS

0

15

30

45

60

0

45

90

135

180

0.1 1 10 100 1000 10000

Error Amplifier Block

Voltage Gain, Phase vs. Frequency

(V+=3.3V, Gain=40dB, Ta=25 oC)

Phase Φ (deg)

Frequency f (kHz)

Voltage Gain Av (dB)

Phase

Gain

0

0.4

0.8

1.2

1.6

2

1 10 100 1000

Switching Current I

SW (mA)

Output High Level ON Resistance

ROH (W)

Output Block

Output High Level ON Resistance

vs. Switching Current (Ta=25

oC)

V+=2.2V

V+=3.3V

V+=7V

0

0.4

0.8

1.2

1.6

2

1 10 100 1000

Switching Current I

SW (mA)

Output Low Level ON Resistance

ROL (Ω)

Output Block

Output Low Level ON Resistance

vs. Switching Current (Ta=25

oC)

V+=2.2V

V+=3.3V

V+=7V

0

0.5

1

1.5

2

2.5

3

-50-250 255075100125150

Ambient Temperature

Ta (oC)

Output High Level ON Resistance

ROH (Ω)

Output Block

Output High Level ON Resistance

vs. Temperature (Isw=-200mA)

V+=2.2V

V+=3.3V

V+=7V

0

0.5

1

1.5

2

2.5

3

-50-250 255075100125150

Ambient Temperature

Ta (oC)

Output Low Level ON Resistance

ROL (Ω)

Output Block

Output Low Level ON Resistance

vs. Temperature (Isw=+200mA)

V+=2.2V

V+=3.3V

V+=7V

NJU7691

-

7

-

Ver.2012-08-03

■ TYPICAL CHARACTERISTICS

2

3

4

5

6

7

8

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

Soft Start Time Tss (ms)

Soft Start Time vs. Temperature

(V+=3.3V)

0.78

0.79

0.8

0.81

0.82

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

Reference Voltage VB (V)

Reference Voltage vs. Temperature

(V+=3.3V, RT=47kΩ)

640

660

680

700

720

740

760

-50-250 255075100125150

Ambient Temperature

Ta (oC)

Oscillator Frequency fOSC (kHz)

Oscillator Frequency vs. Temperature

(V+=3.3V, RT=47kΩ)

200

300

400

500

600

700

800

900

1000

-50-250 255075100125150

Ambient Temperature Ta (oC)

Switching Current Limit ILIM (mA)

Switching Current Limit vs. Temperature

(RT=47kΩ)

V+=2.2V

V+=3.3V

V+=7V

0

0.5

1

1.5

2

2.5

3

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

High Side SW Leak Current ILEAKH (µA)

High Side SW Leak Current vs. Temperature

(V+=3.3V, VON/OFF=0V, RT=47kΩ)

1.8

1.85

1.9

1.95

2

2.05

2.1

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

Threshold Voltage (V)

Under Voltage Lockout Block

vs. Temperature

VT_OFF

VT_ON

NJU7691

-

8

-Ver.2012-08-03

■ TYPICAL CHARACTERISTICS

0

0.5

1

1.5

2

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

Quiescent Current IDD (mA)

Quiescent Current vs. Temperature

(V+=3.3V, RT=47kΩ)

0.0001

0.001

0.01

0.1

1

10

-50 -25 0 25 50 75 100 125 150

Ambient Temperature

Ta (oC)

Standby Current IDD_STB (µA)

Standby Current vs. Temperature

(V+=3.3V, VON/OFF=0V)

[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.