1-Channel Step-Down Switching Regulator

Ordering number : ENA1759A
Bi-CMOS LSI
LV5747NTT
1-channel Step-down Switching
Regulator
Overview
The LV5747NTT 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
Allowable pin voltage
Supply voltage
Symbol
Conditions
VIN max
Ratings
Unit
45
V
VIN, SW
45
V
HDRV, CBOOT
52
V
LDRV
6.0
V
Between CBOOT to SW
6.0
V
Between CBOOT to HDRV
EN, ILIM
Between VIN to ILIM
VDD
SS, FB, COMP
Mounted on a specified board. *
VIN+0.3
V
1.0
V
6.0
V
VDD+0.3
V
0.75
W
Allowable Power dissipation
Pd max
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.
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.
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' s products or
equipment.
60910 SY/60210 SY PC 20100517-S00001 No.A1759-1/5
LV5747NTT
Recommended Operating Range 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
Parameter
Symbol
Conditions
Ratings
min
typ
Unit
max
Reference voltage block
Internal reference voltage
Vref
Including offset of E/A
5V power supply
VDD
IOUT = 0 to 5mA
0.698
0.708
0.718
V
4.7
5.2
5.7
V
260
300
340
kHz
Triangular waveform oscillator block
Oscillation frequency
FOSC
Frequency variation
FOSC DV
VIN = 8 to 42V
Oscillation frequency fold back
VOSC FB
FB voltage detection after SS ends
FOSC FB
VFB = 0V
IC start-up EN voltage
VEN on
VIN = 8 to 42V
IC off EN voltage
VEN off
1
%
0.5
V
detection voltage
Oscillation frequency after fold back
25
45
60
kHz
3.4
4.3
V
ON/OFF circuit block
1.1
1.3
4
5
V
Soft start circuit block
ISS SC
EN > 4.3V
Soft start sink current
ISS SK
EN < 1V, VDD = 5V
Soft start end voltage
VSS END
0.9
1.1
1.3
UVLO lock release voltage
VUVLO
7.0
7.4
7.8
UVLO hysteresis
VUVLO H
Soft start source current
6
2
μA
mA
V
UVLO circuit block
0.6
V
V
Error amplifier
Input bias current
IEA IN
Error amplifier gain
GEA
Common mode input range
VEA R
1000
VIN = 8 to 42V
Sink output current
IEA OSK
FB = 1.0V
Source output current
IEA OSC
FB = 0V
Current detection amplifier gain
GISNS
1400
0.0
100
nA
1800
μA/V
1.6
V
-100
μA
100
μA
1.3
over current limiter circuit block
Reference current
ILIM
Over current detection comparator
VLIM OFS
+10%
μA
-5
+5
mV
VIN-0.45
VIN
V
-10%
20
offset voltage
Over current detection comparator
common mode input range
PWM comparator
Input threshold voltage
Maximum ON duty
Vt max
Duty cycle = DMAX, SW = VIN
1.0
1.1
1.2
V
Vt0
Duty cycle = 0%, SW = VIN
0.4
0.5
0.6
V
DMAX
92
%
Output block
Output stage ON resistance
RONH
5
Ω
RONL
5
Ω
(the upper side)
Output stage ON resistance
(the under side)
Output stage ON current
IONH
240
mA
IONL
240
mA
(the upper side)
Output stage ON current
(the under side)
The whole device
Standby current
ICCS
EN < 1V
Mean consumption current
ICCA
EN > 4.3V
60
3.3
μA
mA
No.A1759-2/5
LV5747NTT
Package Dimensions
unit : mm (typ)
3375
Allowable power dissipation, Pd max -- W
3.0
0.5
3.0
4.9
12
1 2
(0.25)
Pd max -- Ta
1.0
0.125
0.5
1.1 MAX
0.8
0.75
0.6
0.4
0.36
0.2
0
--40
--20
0
20
40
60
8085
100
Ambient temperature, Ta -- °C
0.08
(0.85)
0.2
Specified board : 35 × 32 × 1.6mm3
glass epoxy 2-layer board.
SANYO : MSOP12(150mil)
Pin Assignment
12 SS
FB 1
11 ILIM
COMP 2
EN 3
SW 4
LV5747NTT
10 VIN
9 GND
8 VDD
CBOOT 5
7 LDRV
HDRV 6
Top view
No.A1759-3/5
LV5747NTT
Block Diagram
VIN 10
5V
REGULATOR
+
OCP Comp
ILIM 11
20μA
REFERENCE
VOLTAGE
SS 12
FB 1
0.7V
COMP 2
+
+
-
+
-
SD
VIN
+
Current
Amp
5 CBOOT
6 HDRV
S Q
R
DMAX = 90%
SAW WAVE
OSCILLATOR
fosc forcec
1/8
Err
Amp
0.5V
+
-
UVLO
S Q
R
5μA
1.1V
SD
TSD
1.1V
0.5V
+
PWM Comp
CONTROL
Logic
4 SW
5V
7 LDRV
shut down(SD)
FFOLD
Amp
8 VDD
9 GND
3
EN
Pin Function
Pin No.
1
Pin name
FB
Description
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, the frequency fold back function operations, 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 FB.
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
11
ILIM
Reference current pin for current detection. The sink current of about 20μA flows to this pin.
function, The IC starts and the soft start function operates.
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.A1759-4/5
LV5747NTT
Sample Application Circuit
VIN =
8.0 to 42V
C1
C7
R5
10
VIN
C6
11
ILIM
CBOOT 5
C2
Q1
HDRV 6
3 EN
ON/OFF
L
OUT
SW 4
Q2
12 SS
2 COMP
C5
R1
C4
C9
FB 1
C10
D1
R2
C3
D2 R4
LDRV 7
C11
GND
9
VDD 8
C8
R3
GND
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products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition
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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semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or
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Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification" for the
SANYO Semiconductor Co.,Ltd. product that you intend to use.
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 June, 2010. Specifications and information herein are subject
to change without notice.
PS No.A1759-5/5
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