LV5747TT - SANYO Electric Co., Ltd.

Orderin

numbe

: ENA1448A

Bi-CMOS LSI

1-channel Step-down Switching

Regulator

LV5747TT

Overview

The LV5747TT is a 1-channel step-down switching regulator.

Functions

• 1 channel step-down switching regulator controller.

• Frequency decrease function at pendent.

• Load-independent soft start circuit.

• ON/OFF function.

• Built-in pulse-by-pulse OCP circuit. It is detected by using ON resistance of an external MOS.

Specifications

Absolute Maximum Ratings at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

supply voltage VIN max 45 V

VIN, SW 45 V

HDRV, CBOOT 52 V

LDRV 6.0 V

Between CBOOT to SW,

Between CBOOT to HDRV 6.0 V

EN, ILIM VIN+0.3 V

Between VIN to ILIM 1.0 V

VDD 6.0 V

Allowable pin voltage

SS, FB, COMP VDD+0.3 V

Allowable Power dissipation Pd max Mounted on a specified board. * 0.75 W

Junction temperature Tj max 150 °C

Operating temperature Topr -40 to +85 °C

Storage temperature Tstg -55 to +150 °C

* Specified board: 35mm × 32mm × 1.6mm, glass epoxy 2-layer board.

Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate

the performance, characteristics, and functions of the described products in the independent state, and are not

guarantees of the performance, characteristics, and functions of the described products as mounted in the

customer

s products or equipment. To verify symptoms and states that cannot be evaluated in an independent

device, the customer should always evaluate and test devices mounted in the customer

sproductsor

equipment.

Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to

"standard application", intended for the use as general electronics equipment (home appliances, AV equipment,

communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be

intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace

instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety

equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case

of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee

thereof. If you should intend to use our products for applications outside the standard applications of our

customer who is considering such use and/or outside the scope of our intended standard applications, please

consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our

customer shall be solely responsible for the use.

11310 SY / 42209 MS 20090402-S00001 No.A1448-1/5

LV5747TT

No.A1448-2/5

Recommended Operating Ranges at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Supply voltage range VIN 8.0 to 42 V

Error amplifier input voltage VFB 0 to 1.6 V

Electrical Characteristics at Ta = 25°C, VIN = 24V

Ratings

Parameter Symbol Conditions min typ max

Unit

Reference voltage block

Internal reference voltage Vref Including offset of E/A 0.698 0.708 0.718 V

5V power supply VDD I

OUT = 0 to 5mA 4.7 5.2 5.7 V

Triangular waveform oscillator block

Oscillation frequency FOSC 335 385 435 kHz

Frequency variation FOSC DV V

IN = 8 to 42V 1 %

Oscillation frequency fold back

detection voltage VOSC FB FB voltage detection after SS ends 0.5 V

Oscillatory frequency after fold ba ck FOSC FB V

FB = 0V 25 45 60 kHz

ON/OFF circuit block

IC start-up voltage VEN on VIN = 8 to 42V 3.4 4.3 V

start-up voltage hysteresis VEN hys 1.0 1.2 V

Soft start circuit block

Soft start source current ISS SC EN > 4.3V 4 5 6 μA

Soft start sink current ISS SK EN < 1V, VDD = 5V 2 mA

Soft start end voltage VSS END 0.9 1.1 1.3 V

UVLO circuit block

UVLO lock release voltage VUVLO 7.0 7.4 7.8 V

UVLO hysteresis VUVLO H 0.6 V

Error amplifier

Input bias current IEA IN 100 nA

Error amplifier gain GEA 1000 1400 1800 μA/V

Common mode input range VEA R VIN = 8 to 42V 0.0 1.6 V

Sink output current IEA OSK FB = 1.0V -100 μA

Source output current IEA OSC FB = 0V 100 μA

Current detection amplifier gain GISNS 1.3

over current limi ter circ uit block

Reference current ILIM -10% 20 +10% μA

Over current detection comparator

offset voltage VLIM OFS -5 +5 mV

Over current detection comparator

common mode input range V

IN-0.45 VIN V

PWM comparator

Vt max Duty cycle = DMAX, SW = VIN 1.0 1.1 1.2 V Input threshold v oltage

Vt0 Duty cycle = 0%, SW = VIN 0.4 0.5 0.6 V

Maximum ON duty DMAX 85 90 95 %

Output block

Output stage ON resist ance

(the upper side) RONH 5 Ω

Output stage ON resist ance

(the under side) RONL 5 Ω

Output stage ON current

(the upper side) IONH 240 mA

Output stage ON current

(the under side) IONL 240 mA

The whole device

Standby current ICCS EN < 1V 60 μA

Mean consumption current ICCA EN > 4.3V 3.3 mA

LV5747TT

Package Dimensions

unit : mm (typ)

3375

-40 0 20 40 60 80 100

1.0

0.8

0.6

0.4

0.2

Pd max -- Ta

-20 85

0.75

0.36

Ambient temperature, Ta -- °C

Allowable power dissipation, Pd amx -- W

Specified board: 35×32×1.6mm

glass epoxy 2-layer board.

SANYO : MSOP12( 150mil)

3.0

1.1 MAX

3.0

0.5

4.9

0.2

0.5

(0.25)

(0.85)

0.125

0.08

Pin Assignment

6 7

COMP

CBOOT

HDRV

ILIM

VIN

GND

VDD

LDRV

LV5747TT

Top view

No.A1448-3/5

LV5747TT

Block Diagram

REGULATOR

VIN

OCP Comp

REFERENCE

VOLTAGE

VCC

Current Amp

SAW WAVE

OSCILLATOR

5μA

1.1V

0.7V

0.5V

COMP

ILIM

FFOLD

Comp

fosc forced

1/8

DMAX = 90%

1.1V

0.5V

CONTROL

Logic

UVLO

5CBOOT

HDRV

VDD

LDRV

GND

shut down(SD)

PWM Comp

20μA

TSD

Pin Function

Pin No. Pin name Description

1 FB Error amplifier reverse input pin. By operating the converter, the voltage of this pin becomes 0.708V.

The voltage in which the output voltage is divided by an external resistance is applied to this pin. Moreover, when this pin

voltage becomes 0.5V or less after a soft start ends, th e frequency fold back function operati ons, and the oscillating frequency

is falling with the FB voltage.

2 COMP Error amplifier output pin. Connect a phase compensation circuit between this pin and GND.

3 EN ON/OFF pin.

4 SW Pin to connect with switching node. The source of NchMOSFET connects to this pin.

5 CBOOT Bootstrap capacity connection pin. This pin becomes a GATE drive power supply of an external NchMOSFET.

Connect a bypath capacitor between CBOOT and SW.

6 HDRV An external the upper MOSFET gate drive pin.

7 LDRV An external the lower MOSFET gate drive pin.

8 VDD Power supply pin for an external the lower MOS-FET gate drive.

9 GND Ground pin. Each reference voltage is based on the voltage of the ground pin.

10 VIN Power supply pin. This pin is monitored by UVLO function. When the voltage of this pin becomes 7.8V or more by UVLO

function, The IC starts and the soft start function op erat es.

11 ILIM Reference current pin for current detection. The sink current of about 20μA flows to this pin.

When a resistance is connected between this pin and VIN outside and the voltage applied to the SW pin is lower than the

voltage of the terminal side of the resistance, the upper NchMOSFET is off by operating the current limiter comparator.

This operation is reset with respect to each PWM pulse.

12 SS Pin to connect a capacitor for soft start. A capacitor for soft start is charged by using the voltage of about 5μA.

This pin ends the soft start period by using the voltage of about 1.1V and the frequency fold back function becomes active.

No.A1448-4/5

LV5747TT

Sample Application Circuit

C10

COMP

CBOOT

ON/OFF

VIN = 8 to 42V

OUT

HDRV

LDRV

VDD

GND

VIN ILIM

3 4

10 11

C11

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ranges, or other parameters) listed in products specifications of any and all SANYO Semiconductor Co.,Ltd.

products described or contained herein.

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Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed

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This catalog provides information as of January, 2010. Specifications and information herein are subject

to change without notice.

PS No.A1448-5/5