LV56351HA integrates 1ch DC/DC boost converter and 1ch LDO. It is suitable as the power supply for BS/CS
antennas of LCD/PDP TV and BD recorders that require automatic recovery without IC destruction and malfunction
when the output is short-circuited.
Functions
[DC/DC boost converter]
•
Soft-start time: 2.8ms
•
Frequency 425kHz operation
•
Pulse by pulse over current limiter
•
Short circuit protector (SCP)
[LDO]
•
Over current limiter (Fold back)
[All]
•
Under voltage lockout
•
Thermal shutdown protector
•
Power good
Specifications
Maximum Ratings
at Ta = 25°C
Parameter
VCC maximum supply voltage
LDOIN maximum input voltage
SW maximum voltage
Allowable power dissipation
Operating temperature
Operating junction temperature
Storage temperature
Allowable
pin
voltage
VCC, EN
SW, LDOIN, LDOOUT
IN1, IN2, FB, SCP, PGOOD, DDCTL
Symbol
VCC max
VLDOIN max
VSW max
Pd max
Topr
Tjopr
Tstg
*1
Conditions
Ratings
-0.3 to 25
-0.3 to 30
-0.3 to 30
1.45
-30 to +85
-30 to +125
-40 to +150
25
30
6
Unit
V
V
V
W
°C
°C
°C
V
V
V
*1 Mounted on a specified board : 32mm × 38mm × 1.6mm, glass epoxy, double side board.
Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time.
Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current,
high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details.
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Semiconductor Components Industries, LLC, 2013
August, 2013
O3112NKPC 20121009-S00001 No.A2145-1/9
LV56351HA
Recommended Operating Conditions
at Ta = 25°C
Parameter
VCC supply voltage
LDOIN input voltage
SW voltage
EN voltage
Symbol
VCC
VLDOIN
VSW
VEN
Conditions
Ratings
8 to 23
8 to 28
-0.3 to 28
0 to 23
Unit
V
V
V
V
Electrical Characteristics
at Ta
=
25°C, VCC = 12V, VEN=2V, LDOIN=16V, LDOOUT=15V
Parameter
All
Supply current1
Supply current2
Reference voltage
Enable voltage
Disable voltage
EN input current
PGOOD threshold
PGOOD sink current
PGOOD leak current
UVLO on voltage
Thermal shutdown temperature
TSD hysteresis
DC/DC boost converter
FB output voltage ”Low”
FB output voltage “High”
Soft-start time
Oscillator frequency
Max on duty
SW on resistance
SW peak current
SCP source current
SCP threshold
DDCTL on voltage
DDCTL off voltage
DDCTL input current
LDO
Maximum output current
Line regulation
Load regulation
Dropout voltage
Short current
*2: Design guarantee value.
IOMAX
RLN
RLD
VDROP
ISHORT
16V
<
LDOIN
<
21V
10mA
<
IO
<
300mA
IO = 300mA
LDOOUT = GND
0.25
350
520
670
20
20
0.4
100
mA
mV
mV
V
mA
FBLow
FBHigh
TSS
FOSC
DMAX
RON
IPK
ISCP
VSCP
VDDCTLON
VDDCTLOFF
IDDCTL
DC/DC Off
DC/DC On
VDDCTL = 2V
2.0
0.4
20
1.5
78
IN1 = 2.0V, IFB = -20μA (Sink)
IN1 = 0.2V, IFB = 20μA (Source)
1.8
2.8
425
85
0.7
1.8
4.8
VREF
92
0.2
V
V
ms
kHz
%
Ω
A
μA
V
V
V
μA
ICC
IOFF
VREF
VEN
VDIS
IEN
VPG
IPG
IPGLK
VUVLO
TTSD
THYS
*2
*2
130
30
VEN = 2.0V
IN1
≥
VREF×85% and IN2
≥
VREF×85%
VPGOOD = 0.5V
VPGOOD = 2V
7.0
VREF×0.85
1.0
10
Switching is turned off
EN = 0V
1.2348
2.0
0.4
10
1.26
1.8
3.5
10
1.2852
mA
μA
V
V
V
μA
V
mA
μA
V
°C
°C
Symbol
Conditions
Ratings
min
typ
max
Unit
No.A2145-2/9
LV56351HA
Package Dimensions
unit : mm (typ)
3313A
6.5
14
2.0
Pd max -- Ta
Mounted on the specified board: 32×38×1.6mm
3
glass epoxy, double side board.
Allowable power dissipation, Pd max -- W
1.5
1.45
4.4
6.4
1.0
0.5
1 2
0.22
1.3
(2.28)
0.65
0.15
0.5
0.58
1.5 MAX
0
--30
0
30
60
90
120
1.5
SANYO : HSSOP14(225mil)
Specified board
(32mm
×
38mm
×
1.6mm, glass epoxy, double side board)
SC
P
PGOOD
V1
R1 R3
R7
L1
0.1 (1.3)
Ambient temperature, Ta --
°C
C6 R6 R2 R4
DDCTL
EN
C1
C2
D1
C4
C5
R5 C7
LDOIN
C3
VCC
LDOOUT
GND
〈〈front〉〉
〈〈back〉〉
Pin assignment
Fin
1
2
3
4
5
6
7
PGND
LDOOUT
LDOIN
NC
IN2
IN1
FB
SGND
Top view
PGND
SW
NC
VCC
EN
DDCTL
SCP
PGOOD
Fin
14
13
12
11
10
9
8
No.A2145-3/9
LV56351HA
Pin function
Pin No.
1
2
7
Pin name
LDOOUT
LDOIN
SGND
LDO output
LDO input
Signal ground (*3)
Function
Equivalent circuit
2 LDOIN
1 LDOOUT
7 SGND
4
IN2
LDO feedback input
IN2 4
10kΩ
SGND 7
5
IN1
DC/DC error amplifier input
IN1 5
10kΩ
SGND 7
6
FB
DC/DC error amplifier output
FB 6
1kΩ
SGND 7
8
PGOOD
Power good output
8 PGOOD
500Ω
7 SGND
9
SCP
DC/DC SCP capacitor connect pin for timer setting
300Ω 2kΩ
9 SCP
7 SGND
10
DDCTL
DC/DC on and off control
SGND 7
11
12
EN
VCC
Enable
Power supply
VCC 12
210kΩ
Continued on next page.
No.A2145-4/9
EN 11
410kΩ
SGND 7
*3: When you use this IC, Please short-circuit all the pins of SGND and PGND on the IC mounting side.
210kΩ
110kΩ
DDCTL 10
VREG
LV56351HA
Continued from preceding page.
Pin No.
14
Fin
SW
PGND
Pin name
Function
DC/DC open drain output
Power ground (*3)
Equivalent circuit
VREG
14 SW
Fin
PGND
*3: When you use this IC, Please short-circuit all the pins of SGND and PGND on the IC mounting side.
Function overview
(1) UVLO (Under Voltage Lockout)
UVLO stops outputs of both DC/DC and LDO to prevent malfunction when VCC decreases. UVLO operates when
VCC falls below the UVLO voltage. This function is a non-latch-type, and recovers these outputs automatically when
VCC exceeds the UVLO voltage.
(2) Power good
Power good notifies that the output voltages of DC/DC and LDO are within the range of the setting voltage. The two
output voltages are monitored through the voltage of IN1 and IN2. The output is judged to be “power good” when both
outputs are 85% or higher compared to the setting voltages. If either IN1 or IN2 voltage falls below VREF×85%,
PGOOD output becomes L
→
H (No Good). When IN1 and IN2 voltages become (VREF×85%) + 30mV or higher,
PGOOD output becomes H
→
L (Good). During soft start, the output is H (No Good).
〈〈Power
good circuit diagram〉〉
Power supply (6V or less)
P. Good
Comp.
IN1
IN2
+
+
-
PGOOD
_Pin
10kΩ (Example)
Good
⇒
L output
No Good
⇒
H output
VREF
×
85%
(Hysteresis=30mV)
(3) Pulse-by-Pulse over current protection (P by P)
The P by P stops switch-on operation of a certain cycle by force when the current of power MOSFET reaches the
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