ROHM BD4725G

Voltage Detector ICs
Bipolar
Voltage Detector ICs
No.10006ECT05
BD47□□G series
 Description
The BD47□□G Series is a reset IC that was developed to prevent system errors at transient state when the power of CPU
or logic circuit switches ON/OFF or momentary shut down. These ICs consist of three terminals (power supply, GND and
reset output) to detect power supply voltages and outputs reset signals of various systems. These ICs are ultra-compact
and are realized low current consumption, making them ideal for portable products.
 Features
1) Detection voltage range: 0.1-volt step line-up 1.9~4.6V (Typ.)
2) High accuracy voltage detection: ±1%
3) Low current consumption
4) Open collector “L” reset output
5) Compact SSOP5 package
 Applications
All electronic devices that use microcontrollers and logic circuits
 Selection Guide
No.
Part Number : BD47
G
1
Specifications
Detection Voltage
Description
Example: Voltage range over 1.9V~4.6V in
0.1V increments.
2.9V is marked as “29”
1
 Lineup
Marking
B2
B1
BZ
BY
BX
BW
BV
BU
BT
BS
Detection
Voltage
4.6V
4.5V
4.4V
4.3V
4.2V
4.1V
4.0V
3.9V
3.8V
3.7V
Part Number
Marking
BD4746
BD4745
BD4744
BD4743
BD4742
BD4741
BD4740
BD4739
BD4738
BD4737
BR
BQ
BP
B4
BN
BM
BL
BK
BJ
B3
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Detection
Voltage
3.6V
3.5V
3.4V
3.3V
3.2V
3.1V
3.0V
2.9V
2.8V
2.7V
1/7
Part Number
Marking
BD4736
BD4735
BD4734
BD4733
BD4732
BD4731
BD4730
BD4729
BD4728
BD4727
BH
BG
BF
BE
BD
BC
BB
BA
Detection
Voltage
2.6V
2.5V
2.4V
2.3V
2.2V
2.1V
2.0V
1.9V
Part Number
BD4726
BD4725
BD4724
BD4723
BD4722
BD4721
BD4720
BD4719
2010.04 - Rev.C
Technical Note
BD47□□G series
 Absolute maximum ratings (Ta=25°C)
Parameter
Power Supply Voltage
Output Voltage
*1 *2
Power Dissipation
Operating Temperature
Ambient Storage Temperature
Symbol
Vcc-GND
Vout
Limits
-0.3 ~ +10
-0.3 ~ +10
Unit
V
V
Pd
Topr
Tstg
540
-40 ~ +75
-55 ~ +125
mW
°C
°C
*1 When a ROHM standard circuit board (70mm×70mm×1.6mm glass epoxy board) is mounted.
*2 When used at temperatures higher than Ta=25°C, the power is reduced by 5.4mW/°C
 Electrical characteristics (Unless Otherwise Specified Ta=25°C)
Parameter
Symbol
Detection Voltage
Vs
Temperature Coefficient
Of Detection Voltage
Detection Hysteresis Voltage
Transfer Delay Time ”H”
Transfer Delay Time ”L”
Reset Output Voltage ”L”
Circuit Current ON
Circuit Current OFF
Threshold Operating Voltage
Output Leak Current
Reset Output Current ”L”
Condition
Vcc=HL
Min.
Vs (T)
×0.99
RL=4.7kΩ
Vs/∆T
RL=4.7kΩTa=-20~+75°C Designed Guarantee
∆Vs
tPLH
tPHL
VOL
Icc1
Icc2
VOPL
IL
IOL
RL=4.7kΩ, Vcc＝LHL
CL=100pF，RL=4.7kΩ *1
CL=100pF，RL=4.7kΩ *2
Vcc=Vs(min.)-0.05V, RL=4.7kΩ
Vcc=Vs(min.)-0.05V, RL=∞
Vcc=Vs(typ.)/0.85V, RL=∞
RL=4.7kΩ，VOL≥0.4V
Vcc=VOUT=10V
Vo=0.4V, Vcc=Vs(min.)-0.05V
Limit
Typ.
Max.
Vs (T)
×1.01
Vs (T)
Unit
V
-
±0.01
-
%/°C
30
3.0
50
20
60
0.1
1.5
1.6
0.65
15.0
100
50
120
0.4
3.0
3.2
0.85
0.1
-
mV
µs
µs
V
µA
µA
V
µA
mA
Vs(T):Standard Detection Voltage（1.9V to 4.6V, 0.1V step）
RＬ:Pull-up resistor to be connected between VOUT and power supply.
CL:Capacitor to be connected between VOUT and GND.
*1 tPLH:Vcc=(Vs(typ.)-0.4V)(Vs(typ.)+0.4V)
*2 tPHL:Vcc=(Vs(typ.)+0.4V)(Vs(typ.)-0.4V)
Designed Guarantee.(Outgoing inspection is not done on all products.)
 Block Diagrams
VCC
5
TOP VIEW
PIN No.
Symbol
Function
1
N.C.
Unconnected Terminal
2
SUB
Substrate*
3
GND
GND
4
VOUT
Reset Output
5
VCC
4
VOUT
Vref
SSOP5
3
Power Supply Voltage
*Substrate Pin should be connected with GND
GND
Fig.1
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2/7
2010.04 - Rev.C
Technical Note
BD47□□G series
7
6
5
4
3
2
Icc1=1.34μA
Icc2=1.46μA
1
0
0
1
2
3
4
5
6
7
8
6
【BD4729G】
700
600
500
400
IOL=12.194mA at Vo=400mV
300
200
100
0
9 10
0
VCC SUPPLY VOLTAGE ：VCC [V]
600
500
400
VOPL =0.675V
300
200
100
DETECTION VOLTAGE： VS[V]
OUTPUT VOLTAGE： VOUT [mV]
700
10
15
20
25
0
0.5
1
1.5
2
2
VS=2.90V
2.5
VS=2.95V
1
30
【BD4729G】
3.3
3.1
-0.007%/℃
2.9
2.7
2.5
~
~
2.3
-20 -10 0 10 20 30 40 50 60 70 80
0
dVS=50mV
0
1
2
3
4
5
6
VCC SUPPLY VOLTAGE ：VcC [V]
Fig.4 I/O Characteristics
2.5
【BD4729G】
2.0
1.5
1.0
0.5
0.0
-20 -10 0 10 20 30 40 50 60 70 80
VCC SUPPLY VOLTAGE ： VCC [V]
TEMPERATURE ： Ta[℃]
TEMPERATURE ： Ta[℃]
Fig.5 Operating Limit Voltage
Fig.6 Detection Voltage
Fig.7 Circuit Current when ON
2.5
0.9
【BD4729G】
2.0
1.5
1.0
0.5
0.0
-20 -10 0 10 20 30 40 50 60 70 80
MINIMUM OPERATION VOLTAGE ： VOPL[V]
CIRCUIT CURRENT WHEN OFF ： I CC2[mA]
5
3.5
800
3
Fig.3 “Low” Output Current
1000
【BD4729G】
4
OUTPUT VOLTAGE ： VOUT[mV]
Fig.2 Circuit Current
900
【BD4729G】
5
0
500
【BD4729G】
0.8
0.7
0.6
0.5
0.4
-20 -10 0 10 20 30 40 50 60 70 80
OUTPUT VOLTAGE： VOUT [mV]
CIRCUIT CURRENT ： ICC [μA]
8
800
OUTPUT VOLTAGE： VOUT [V]
【BD4729G】
9
CIRCUIT CURRENT WHEN ON ： ICC1[mA]
10
"LOW" OUTPUT CURRENT ： IOL [mA]
 Reference Data (Unless specified otherwise, Ta=25°C)
【BD4729G】
400
300
Ta=-20℃
200
100
Ta=75℃
Ta=25℃
0
0
1
2
3
4
5
TEMPERATURE ： Ta[℃]
TEMPERATURE ： Ta[℃]
"LOW" OUTPUT CURRENT ： IOL[mA]
Fig.8 Circuit Current when OFF
Fig.9 Operating Limit Voltage
Fig.10 Output Saturation Voltage
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3/7
2010.04 - Rev.C
Technical Note
BD47□□G series
 Explanation of Operation
BD47□□G series has the detection voltages and release voltages as threshold voltages and, as the voltages applied to the
input reach their respective threshold voltages, the output switches from “High” to “Low” and from “Low” to “High”. The
release voltage has a hysteresis that is the detection voltage +50mV (Typ.), preventing chattering in the output. When the
input is greater than the release voltage, the output is in a “High” state. When the input is lowered from that state, the output
switches to “Low” on the detection voltage. When the input is less than the detection voltage, the output is in a “Low” state.
When the input is raised from that state, the output switches to “High” with the release voltage. Additionally, at least 0.85V is
required for the circuit to operate fully. When the input falls below the operating limit voltage, the output becomes unsettled.
VDD
VDD
VS+ΔVS
VS
⑤
VOPL
0V
VOUT
VOH
TPHL
TPLH
TPLH
TPHL
VOL
①
②
③
④
Fig.11 Timing Waveform
1
When the power supply is turned on, the output is unsettled from after over the operating limit voltage (VOPL) until
TPHL. Therefore it is possible that the reset signal is not outputted when the rise time of Vcc is faster than TPHL.
2
When Vcc is greater than VOPL but less than the reset release voltage (VS + ΔVS), the output voltages will switch to
Low.
3
If Vcc exceeds the reset release voltage (VS + ΔVS), then VOUT switches from L to H.
4
If Vcc drops below the detection voltage (VS) when the power supply is powered down or when there is a power supply
fluctuation, VOUT switches to L (with a delay of TPHL).
5
The potential difference between the detection voltage and the release voltage is known as the hysteresis width (ΔVS).
The system is designed such that the output does not flip-flop with power supply fluctuations within this hysteresis width,
preventing malfunctions due to noise.
<Precautions>
Please be aware that when there is resistance on the power supply line, the detection voltage varies with voltage drops
caused by the IC current consumption.
Please connect a capacitor between VCC and GND when the power supply line has high impedance.
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4/7
2010.04 - Rev.C
Technical Note
BD47□□G series
 Circuit Applications
1) The following is an example of an application circuit using Reset IC for normal power supply detection. BD47□□G
series requires a pull up resistor on the output terminal. The pull up resister value should be decided. As the
application with enough confirmation of power supply level and output current capability. When a capacitor has been
inserted into the output terminal to delay the output time or to remove noise, the output will be slower during starting or
stopping. Please be careful to select the appropriate pull up resistors, output current and capacitor when inserting a
bypass capacitor between input and GND. Please be aware that if an extremely large capacitor is used, the response
time will become excessively slow.
●●●●●●●●●●●●
VCC
5
microcontroller
4
●●●●●●●●●●●
VDD
Reset Pin
VOUT
●●●●●●●●●●●●
Vref
3
BD47□□G
GND
Fig.12
2)
The following shows an example of adding delay time to a reset signal. It is possible to set the delay time using the
capacitor CL and the resistor RL connected to the output terminal as shown below. At VCC start up, CL will be
charged by RL. The CL and RL time constants and the threshold voltage of the Reset terminal determine the charge
delay time. When VCC is decreased, CL is discharged through the Reset IC. The sum of the respective times plus the
delay time of the IC itself becomes the reset signal delay time.
VCC
VDD
RL
BD47□□G
CPU
Micro-controller
RESET
VOUT
CL
GND
VCC
GND
VCC
VS+ΔVS
VS
0V
VOH
RESET
(=VOUT)
TPLH
TPHL
TPLH
VOL
Fig.13
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5/7
2010.04 - Rev.C
Technical Note
BD47□□G series
 Operation Notes
1. Absolute maximum range
Absolute Maximum Ratings are those values beyond which the life of a device may be destroyed. We cannot be defined the
failure mode, such as short mode or open mode. Therefore a physical security countermeasure, like fuse, is to be given
when a specific mode to be beyond absolute maximum ratings is considered.
2.
GND potential
GND terminal should be a lowest voltage potential every state. Please make sure all pins, which are over ground even if,
include transient feature.
3.
Electromagnetic Field
Mal-function may happen when the device is used in the strong electromagnetic field.
4.
Bypass Capacitor for Noise Rejection
Please put into the capacitor between VCC pin and GND, to reject noise. If extremely big capacitor is used, transient
response might be late. Please confirm sufficiently for the point.
5.
Short Circuit between Terminal and Soldering
Don’t short-circuit between Output pin and VCC pin, Output pin and GND pin, or VCC pin and GND pin. When soldering the
IC on circuit board, please be unusually cautious about the orientation and the position of the IC. When the orientation is
mistaken the IC may be destroyed.
6.
This IC has extremely high impedance terminals. Small leak current due to the uncleanness of PCB surface might cause
unexpected operations. Application values in these conditions should be selected carefully. If the leakage is assumed
between the VOUT terminal and the GND terminal, the pull-up resistor should be less than 1/10 of the assumed leak
resistance.
7. External parameters
The recommended parameter range for RL is 2kΩ~1MΩ. There are many factors (board layout, etc) that can affect
characteristics. Please verify and confirm using practical applications.
8.
Power on reset operation
Please note that the power on reset output varies with the Vcc rise up time. Please verify the actual operation.
9.
Precautions for board inspection
Connecting low-impedance capacitors to run inspections with the board may produce stress on the IC. Therefore, be
certain to use proper discharge procedure before each process of the test operation.
To prevent electrostatic accumulation and discharge in the assembly process, thoroughly ground yourself and any
equipment that could sustain ESD damage, and continue observing ESD-prevention procedures in all handing, transfer
and storage operations. Before attempting to connect components to the test setup, make certain that the power supply is
OFF. Likewise, be sure the power supply is OFF before removing any component connected to the test setup.
10. When the power supply, is turned on because of in certain cases, momentary Rash-current flow into the IC at the logic
unsettled, the couple capacitance, GND pattern of width and leading line must be considered.
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6/7
2010.04 - Rev.C
Technical Note
BD47□□G series
 Part Number Selection
B
D
4
7
1
Bipolar Reset
9
－
G
T
R
Detection Voltage
SSOP5
Taping Specifications
Example: 1.9V19
Package
Embossed Taping
SSOP5
5
4
1
2
0.2Min.
+0.2
1.6 −0.1
2.8±0.2
<Tape and Reel information>
+6°
4° −4°
2.9±0.2
3
Tape
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
TR
The direction is the 1pin of product is at the upper right when you hold
( reel on the left hand and you pull out the tape on the right hand
1pin
+0.05
0.13 −0.03
1.25Max.
)
0.05±0.05
1.1±0.05
S
+0.05
0.42 −0.04
0.95
0.1
S
Direction of feed
Reel
(Unit : mm)
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7/7
∗ Order quantity needs to be multiple of the minimum quantity.
2010.04 - Rev.C
Notice
Notes
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The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
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R1010A