Datasheet
6.0V½28V, 1.2A 1ch
1ch Step-Down Switching Regulator
BD9E151NUX
General Description
The BD9E151NUX is a 28V, 1.2A diode-rectification
buck converter that integrated internal high-side 30V
Power MOSFET. To increase efficiency at light loads, a
pulse skipping is automatically activated. Furthermore,
the 0uA shutdown supply current allows the device to be
used in battery powered application. Current mode
control with internal slope compensation simplifies the
external component count while allowing the use of
ceramic output capacitors.
Packages
VSON008X2030
2.00mm x3.00mm x 0.60mm
Key Specifications
■
Input Voltage
■
Ref. Precision (Ta=25℃)
■
Max Output Current
■
Operating Temperature
6½28 [V]
±1.0[%]
1.2 [A] (Max.)
-40℃~85℃
Features
■
High and Wide Input Range (VIN=6V~28V)
■
30V/80mΩ
Internal Power MOSFET
■
600kHz Fixed Operating Frequency
■
Feedback Pin Voltage 1.0V±1.0%
■
Internal Over Current Protection(OCP), Under
Voltage Locked Out(UVLO), Over Voltage
■
Protection(OVP), Thermal Shut down(TSD)
■
■
0μA Low Shutdown Supply Current
■
VSON008X2030
package
Typical Application Circuits
CBST: 0.1uF
VSON008X2030
Applications
Surveillance Camera Applications
OA Applications
12V, 24V Distributed Power Systems
■
1
CVCC: 10uF/35V
VIN
BST
LX
8
D1
LO: 15uH
VOUT
CO: 47uF/16V
2
VIN
GND
7
ON/OFF
control
3
EN
VC
6
C1: 10000pF
R4:
Ω
4
CSS: 0.047uF
SS
FB
5
R :
Ω
R5:
Ω
Figure 1. Typical Application Circuit
○Structure：Silicon
Monolithic Integrated Circuit
○This product is not designed for normal operation within a radioactive
○Product
structure：Silicon monolithic integrated circuit
.
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© 2013 ROHM Co., Ltd. All rights reserved.
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○This
product has not designed protection against radioactive rays
1/19
TSZ02210-0Q3Q0AZ00160-1-2
2015.02.04 Rev.002
BD9E151NUX
Pin Configuration
BST
VIN
EN
SS
1
2
3
4
8
7
6
5
Lx
GND
VC
FB
Back side
PAD
Figure 2. Pin Configuration (TOP VIEW)
Pin Description
Pin No.
1
2
3
4
5
6
7
6
-
Pin Name
BST
VIN
EN
SS
FB
VC
GND
LX
Back side
PAD
Description
The pin is power supply for floating Power NMOS driver. Connect bypass capacitor
between the pin and LX pin for bootstrap operation.
Input supply. Place bypass capacitor as close as possible to this pin.
Enable input pin. Apply more than 2.4V to start-up the DCDC. This pin is pulled down by
700kΩ,
apply less than 0.8V or open to shutdown the DCDC.
Soft start pin. An external capacitor connected to this pin sets output rise time.
Inverting node of the gm amplifier.
Error amplifier output, and input to the PWM comparator. Connect phase compensation
components to this pin.
Ground.
Place schottky barrier diode as close as possible and inductor to this pin.
PAD for radiation of heat. Connect to GND is recommended.
Block Diagram
ON/OFF
EN
VIN
TSD
UVLO
Reference
VREF
REG
Current Sense
AMP
shutdown
BST
Current
Comparator
80mΩ
FB
1.0V
-
+
+
Error
AMP
Σ
-
+
R Q
S
LX
VOUT
SS
Soft
Start
Oscillator
GND
VC
Figure 3. Block Diagram
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BD9E151NUX
Description of Blocks
1.
Reference
This block generates reference voltage and current. It start operation by applying EN=H.
It provides reference voltage and current to error amplifier, oscillator, and etc.
2.
REG
This is a gate drive voltage generator and 5.5V regulator for internal circuit power supply.
3.
OSC
This is a precise wave oscillation circuit with operation frequency fixed to 600 kHz.
4.
Soft Start
This block does Soft Start to the output voltage of DC/DC converter, and prevents in-rush current during Start-up.
Soft Start Time set by the capacitor connected to SS pin and SS charge current.
5.
ERROR AMP
This is an error amplifier that detects output signal, and outputs PWM control signal. Internal reference voltage is set
to 1.0V. Connect phase compensation components between this pin and ground (ref. p.12).
6.
OVP
The OVP circuit includes an overvoltage comparator to compare the FB pin voltage and internal thresholds. When the
FB pin voltage goes above 110%×FB,
the high-side MOSFET will be forced off. When the FB pin voltage falls
below 105%, the high-side MOSFET will be enabled again.
7.
ICOMP
The BD9E151NUX implements current mode control that uses the VC pin voltage to turn off the high-side MOSFET on a
cycle by cycle basis. Every cycle the switch current and the COMP pin voltage are compared; when the peak inductor
current intersects the VC pin voltage, the high-side switch is turned off. During overcurrent conditions that pull the output
voltage low, the error amplifier responds by driving the COMP pin high, causing the switch current to increase.
8.
OCP
This is a circuit to protect the high-side FET from overcurrent. Every cycle the switch current and the reference voltage
of overcurrent protection are compared; when the peak inductor current intersects the reference voltage, the high-side
switch is turned off. Once overcurrent is detected, the device will stop and VC pin voltage will be reset and SS pin
voltage will be discharged by 2uA (hiccup operation). Then SS pin voltage reaches to less than 0.1V, IC will restart.
9.
High-side MOSFET
This is a 30V/80mΩ
high-side
MOSFET that converts inductor current of DC/DC converter.
Because the current limiting of this FET is 1.6A included ripple current, please use at within1.6A.
10. UVLO
This is a low voltage error prevention circuit.
This prevents internal circuit error during increase of power supply voltage and during decline of power supply voltage.
It monitors VIN pin voltage and internal REG voltage, and when VIN voltage becomes 5.2V and below, it turns OFF all
output FET and turns OFF DC/DC comparator output and Soft Start circuit resets.
Now this Threshold has hysteresis of 200mV.
11. TSD
This is a heat protect circuit.
When it
detects an abnormal temperature exceeding maximum junction temperature (Tj=150℃), it turns OFF all Output
FET, and turns OFF DC/DC converter output. When temperature falls, it automatically returns.
12. EN
When a Voltage of 2.4V or more is applied, it turns ON, at Open or 0V application, it turns OFF.
About 700kΩ
Pull-down
Resistance is contained within the Pin.
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TSZ22111・15・001
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TSZ02210-0Q3Q0AZ00160-1-2
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BD9E151NUX
Absolute Maximum Ratings
Item
VIN to GND
BST to GND
BST to LX
EN to GND
LX to GND
FB to GND
VC to GND
SS to GND
High-side FET Drain Current
Power Dissipation
Operating Temperature
Storage Temperature
Junction Temperature
(*1)During
mounting of
70×70×1.6
t
Symbol
VIN
VBST
⊿VBST
VEN
VLX
VFB
VSS
VSS
IDH
Pd
Topr
Tstg
Tjmax
Ratings
30
37
7
30
30
7
7
7
1.6
2
(*1)
-40½+85
-55½+125
150
Unit
V
V
V
V
V
V
V
V
A
W
℃
℃
℃
mm 4layer board.Reduce by 20mW
for every 1℃ increase. (Above 25℃)
Operating Ratings
Ratings
Min
6
1.0
(*2)
-
Typ
-
-
-
Max
28
VINx0.7
or
VIN-5
(*3)
1.2
Item
Input Voltage
Output Voltage
Output Current
Symbol
VIN
VOUT
IOUT
Unit
V
V
A
(*2)Restricted by minimum on pulse typ. 100nsec
(*3)Restricted by BSTUVLO or Max Duty Cycle (ref. p.14). Please set value of the low one for the maximum.
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TSZ02210-0Q3Q0AZ00160-1-2
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BD9E151NUX
Electrical Characteristics (Unless otherwise specified
Ta=25℃, VIN=12V,
VOUT=5V)
Parameter
Circuit current
Stand-by current of VIN
Circuit current of VIN
Under voltage Lock out (UVLO)
Reset threshold voltage
Hysteresis width
Oscillator
Oscillating frequency
Max duty cycle
Error amplifier
FB threshold voltage
Input bias current
Error amplifier DC gain
Error amplifier transconductance
Current sense amplifier
VC to switch current transconductance
Output
High-side MOSFET ON resistance
Over current detect current
CTL
EN pin control voltage
EN pin input current
SOFT START
Charge current
◎Not designed
to withstand radiation.
Iss
1
2
4
uA
ON
OFF
VEN
VENOFF
REN
2.4
-0.3
6.0
－
－
7.0
VIN
0.8
15.0
V
V
Ta=-40~85℃
VIN=6~28V
RonH
Iocp
－
1.6
80
2.2
160
－
mΩ
A
Ｇ
CS
-
10
20
A/V
VFB
IFB
A
VEA
G
EA
0.990
-1.0
-
-
1.000
0
600
250
1.010
1.0
6000
500
V
uA VFB=0V
V/V
uA/V
IVC=±10uA,VC=1.0V
fsw
Dmax
540
85
600
91
660
-
kHz
%
Vuv
Vuvhy
5.0
－
5.4
200
5.8
400
V
mV
VIN rising
Ist
Icc
－
－
0
0.8
10
1.6
uA VEN=0
mA FB=1.5V
Symbol
Limits
Min.
Typ.
Max
Unit
Conditions
uA VEN=5V
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TSZ22111・15・001
5/19
TSZ02210-0Q3Q0AZ00160-1-2
2015.02.04 Rev.002
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