Datasheet
1.2V to V
CC
-1V, 2.5A 1ch
Ultra Low Dropout Linear Regulator
BD3506F
General Description
The BD3506F is an ultra-low dropout chipset linear
regulator that can achieve ultra-low voltage output
from an ultra-low voltage input. By using N-Channel
MOSFET for built-in power transistor, the regulator can
be used at ultra-low I/O voltage difference up to
voltage difference generated by ON resistor
(R
ON
=120mΩ(Typ)). By reducing the I/O voltage
difference, large current (I
OUTMAX
=2.5A) output is
achieved and conversion loss can be reduced making
it comparable to switching power supply. BD3506F
does not need any choke coil, diode for rectification
and power transistors which are required for switching
power supply. Consequently, total cost of the set can
be reduced and compact size can be achieved for the
set. By using external resistors, output voltages from
0.65V to 2.5V can be set. In addition, since output
voltage start-up time can be adjusted by using the
NRCS terminal, it is possible to meet the power supply
sequence of the set.
Key Specifications
IN Input Voltage Range:
VCC Input Voltage Range:
Output Voltage Range:
Output Current:
ON-Resistance:
Standby Current:
Operating Temperature Range:
1.2V to V
CC
-1V
4.3V to 5.5V
0.65V to 2.5V
2.5A (Max)
120mΩ(Typ)
0µA (Typ)
-10°C to +100°C
Package
W(Typ) x D(Typ) x H(Max)
Features
Built-in high-accuracy reference voltage circuit
(0.65V±1%)
Built-in VCC low input malfunction prevention
circuit (V
CC
= 4.15V)
Reduced rush current by NRCS
Built-in ultra-low on-resistor N-Channel Power
MOSFET
Built-in current limiting circuit (2.5A min)
Built-in thermal shutdown circuit
SOP8
5.00mm x 6.20mm x 1.71mm
Applications
Mobile PC, desktop PC, LCD-TV, DVD, digital home
appliances
Typical Application Circuit and Block Diagram
VCC
VCC
4
VCC
Enable
EN
1
UVLO
Reference
Block
CL
Current
Limit
2
VIN
IN
IN
VIN
OUT1
Vo1
7
CL
UVLO
TSD
8
EN
Vo2
OUT2
VFB
FB
3
NRCS
TSD
6
NRCS
5
GND
R2
R
2
Vo
OUT
Thermal
Shutdown
R
1
R1
○Product
structure：Silicon monolithic integrated circuit
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© 2015 ROHM Co., Ltd. All rights reserved.
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○This
product has no designed protection against radioactive rays
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TSZ02201-0J2J0A601080-1-2
02.Nov.2015 Rev.001
BD3506F
Pin Configuration
TOP VIEW
Pin Descriptions
Pin No.
1
Pin Name
EN
IN
FB
VCC
GND
NRCS
OUT1
OUT2
Enable pin
Input voltage pin
Output voltage feedback
Power source
Ground pin
NRCS(Non rush current on start
up) time setup
OUT1 Pin
OUT2 Pin
Pin Function
EN 1
8
OUT2
VO2
VO1
7
OUT1
2
3
IN
VIN 2
4
5
FB 3
6 NRCS
5 GND
6
7
8
VCC 4
Description of Blocks
1.
AMP
This is an error amplifier that compares the reference voltage (V
REF
) with FB voltage to drive the output N-Channel FET.
The frequency characteristics are optimized so that low ESR functional polymer capacitor can be used for the output
capacitor and high-speed transient response can be achieved. The output voltage range of the AMP section is
GND-VCC. When EN is OFF or at UVLO, the output goes LOW and the output N-Channel FET is turned OFF.
EN
By the logic input pin, regulator ON/OFF is controlled. At the time of OFF, the circuit current is limited to 0 µA to reduce
the standby current consumption of the apparatus. In addition, EN turns ON FET that can discharge NRCS and OUT
and removes excess electric charge to prevent malfunction of IC on the load side. Since there is no electrical
connection with the VCC terminal (as in the case where there is and ESD diode) , operation is independent on the
input sequence.
UVLO
To prevent malfunctions that can occur during sudden decrease in VCC, the UVLO circuit switches the output to OFF
state, and (like the EN block) discharges NRCS and OUT. When the voltage exceeds the threshold voltage (TYP
4.15V), the output is restored.
Current Limit
When the output is ON and the output current exceeds the set current limit threshold (2.5A or more) , the output
voltage is attenuated to protect the IC on the load side. When current decreases, the output voltage is restored returns
to the allowable value.
NRCS
By connecting an external capacitor to NRCS pin and GND, soft start function is enabled. The output voltage startup
time is determined by the time when the NRCS terminal reaches V
FB
(0.65V). During start-up, the NRCS terminal
serves as a constant current source of 20 µA (Typ), and charges the capacitor that is externally connected.
TSD (Thermal Shut down)
In order to prevent thermal breakdown and thermal runaway of the IC, the output is turned OFF when chip temperature
exceeds the threshold temperature. When the temperature decreases below the threshold temperature, the output is
restored. While the TSD circuit is designed to protect the IC in the occurrence of extreme heat, thermal design should
consider not to exceed Tj(max).
IN
The IN line acts as the major current supply line, and is connected to the output N-Channel FET drain. Since there is
no electrical connection with the VCC terminal, as in the case when an ESD diode is connected, its operation does not
depend on the input sequence. However, because of the body diode of the output N-Channel FET, there is electrical
connection (diode connection) between IN and OUT. Consequently, when the output is turned ON and OFF by IN,
reverse current flows, in which case care must be taken.
2.
3.
4.
5.
6.
7.
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BD3506F
Absolute Maximum Ratings
(Ta=25°C)
Parameter
Input Voltage1
Input Voltage2
Enable Input Voltage
Power Dissipation1
Power Dissipation2
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Symbol
V
CC
V
IN
V
EN
Pd1
Pd2
Topr
Tstg
Tjmax
Rating
7
(Note 1)
7
(Note 1)
7
0.56
(Note 2)
0.69
(Note 3)
-10 to+100
-55 to+125
+150
Unit
V
V
V
W
W
°C
°C
°C
(Note 1) Provided Pd is not exceeded.
(Note 2) Derate by 4.48 mW/°C in the case of Ta ≥ 25°C (no heat radiation board),
(Note 3) Derate by 5.52 mW/°C in the case of Ta ≥ 25°C (when mounted on a 70mm x 70mm x 1.6mm glass epoxy substrate),
Caution:
Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated
over the absolute maximum ratings.
Recommended Operating Conditions
(Ta=25°C)
Parameter
Input Voltage1
Input Voltage2
Output Voltage
Enable Input Voltage
Capacitor in NRCS pin
Symbol
V
CC
V
IN
V
OUT
V
EN
C
NRCS
Rating
Min
4.3
1.2
V
FB
-0.3
0.001
Max
5.5
V
CC
-1
(Note 4)
2.5
+5.5
1
Unit
V
V
V
V
µF
(Note 4) However, irrespective of charging order of VCC and IN.
Electrical Characteristics
(Unless otherwise noted, Ta=25°C V
CC
=5V V
EN
=3V V
IN
=1.8V R
1
=3.9kΩ R
2
=3.3kΩ)
Limit
Parameter
Symbol
Unit
Min
Typ
Max
Circuit Current
Shut-Down Mode Current
Output Voltage
Maximum Output Current
Maximum Short Current
Temperature Coefficient of Output
Voltage
Feed Back Voltage 1
Feed Back Voltage 2
Line Regulation 1
Line Regulation 2
Load Regulation
Dropout Voltage
Standby Discharge Current
[Enable]
High Level Enable Input Voltage
Low Level Enable Input Voltage
Enable Pin Input Current
[Voltage Feed Back]
Feed Back Terminal Bias Current
(Note 5) Not 100% tested
Conditions
I
CC
I
ST
V
OUT
I
OUT
I
OST
Tcvo
V
FB1
V
FB2
Reg.l1
Reg.l2
Reg.L
dVo
I
DEN
V
ENHI
V
ENLOW
I
EN
I
FB
-
-
-
2.5
-
-
0.643
0.630
-
-
-
-
150
2
-0.3
-
-100
0.7
0
1.200
-
2.0
0.01
0.650
0.650
0.1
0.1
0.5
120
-
-
-
7
0
1.4
10
-
-
-
-
0.657
0.670
0.5
0.5
10
200
-
5.5
+0.8
10
+100
mA
µA
V
A
A
%/°C
V
V
%/V
%/V
mV
mV
mA
V
V
µA
nA
V
EN
=3V
I
OUT
=50mA
I
OUT
=0 to 2A,
Ta=-10°C to +100°C
(Note 5)
V
CC
=4.3V to 5.5V
V
IN
=1.2V to 3.3V
I
OUT
=0A to 2A
I
OUT
=1A,V
IN
=1.2V,
Ta=-10°C to +100°C
(Note 5)
V
EN
=0V, V
OUT
=1V
V
OUT
=0V
V
EN
=0V
I
OUT
=50mA
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BD3506F
Electrical Characteristics – continued
Parameter
[NRCS]
NRCS Charge Current
NRCS Standby Voltage
[UVLO]
VCC UVLO
VCC UVLO Hysteresis
V
CCUVLO
V
CCHYS
4.00
100
4.15
160
4.30
220
V
mV
VCC: Sweep-up
VCC: Sweep-down
I
NRCS
V
STB
14
-
20
0
26
50
µA
mV
V
NRCS
=0.5V
V
EN
=0V
Symbol
Limit
Min
Typ
Max
Unit
Conditions
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BD3506F
Typical Performance Curves
10
8
Input Current : I
IN
(µA)
IIN(uA)
Feed Back Voltage : V
FB
(mV)
654
653
652
651
650
649
648
647
6
4
2
0
0
4
6
Input Voltage : V
IN
(V)
VIN(V)
Figure 1. Input Current vs Input Voltage
(Ta=25°C)
646
2
8
-10
10
30
50
70
90
Temperature : Ta (°C)
Figure 2. Feed Back Voltage vs Temperature
14
700
Enable Pin Input Current : I
EN
(V)
Feed Back Voltage : V
FB
(mV)
0
1
2
3
4
5
12
10
8
6
4
2
0
600
500
400
300
200
100
0
0
0.2
0.4
0.6
0 .8
1
1.2
Enable Input Voltage : V
EN
(V)
Figure 3. Enable Pin Input Current vs Enable Input
Voltage
V
NRCS
(V)
Figure 4. Feed Back Voltage vs V
NRCS
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TSZ02201-0J2J0A601080-1-2
02.Nov.2015 Rev.001
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