Rohm BD4823G, BD4824G, BD4825G, BD4826G, BD4827G Technical Note

Voltage Detector IC Series

Standard CMOS
Voltage Detector IC

BD48□□G/FVE，BD49□□G/FVE Series

●General Description

ROHM’s BD48□□G/FVE and BD49□□G/FVE series are highly accurate, low current consumption reset IC series. The lineup was

established with tow output types (Nch open drain and CMOS output) and detection voltages range from 2.3V to 6.0V in increments of 0.1V,

so that the series may be selected according the application at hand.

●Features

1） Detection voltage: 2.3V to 6.0V (Typ.), 0.1V steps
2） High accuracy detection voltage: ±1.0%
3） Ultra-low current consumption: 0.8µA (Typ.)
4） Nch open drain output (BD48□□G/FVE), CMOS output (BD49□□G/FVE)
5） Compact packages VSOF5: BD48□□FVE, BD49□□FVE

SSOP5: BD48□□G, B D 4 9 □□G

●Applications

All electronic devices that use microcontrollers and logic circuits

●Selection Guide

TECHNICAL NOTE

Part Number：BD4□ □ □ □

① ③

②

Number

①

②

③ Package G：SSOP5 / FVE: VSOF5

●Lineup

Marking

Detection

Voltage

EW 6.0V BD4860 EB 4.1V BD4841 GW 6.0V BD4960 GB 4.1V BD4941

EV 5.9V BD4859 EA 4.0V BD4840 GV 5.9V BD4959 GA 4.0V BD4940

EU 5.8V BD4858 DV 3.9V BD4839 GU 5.8V BD4958 FV 3.9V BD4939

ET 5.7V BD4857 DU 3.8V BD4838 GT 5.7V BD4957 FU 3.8V BD4998

ES 5.6V BD4856 DT 3.7V BD4837 GS 5.6V BD4956 FT 3.7V BD4937

ER 5.5V BD4855 DS 3.6V BD4836 GR 5.5V BD4955 FS 3.6V BD4936

EQ 5.4V BD4854 DR 3.5V BD4835 GQ 5.4V BD4954 FR 3.5V BD4935

EP 5.3V BD4853 DQ 3.4V BD4834 GP 5.3V BD4953 FQ 3.4V BD4934

EN 5.2V BD4852 DP 3.3V BD4833 GN 5.2V BD4952 FP 3.3V BD4933

EM 5.1V BD4851 DN 3.2V BD4832 GM 5.1V BD4951 FN 3.2V BD4932

EL 5.0V BD4850 DM 3.1V BD4831 GL 5.0V BD4950 FM 3.1V BD4931

EK 4.9V BD4849 DL 3.0V BD4830 GK 4.9V BD4949 FL 3.0V BD4930

EJ 4.8V BD4848 DK 2.9V BD4829 GJ 4.8V BD4948 FK 2.9V BD4929

EH 4.7V BD4847 DJ 2.8V BD4828 GH 4.7V BD4947 FJ 2.8V BD4928

EG 4.6V BD4846 DH 2.7V BD4827 GG 4.6V BD4946 FH 2.7V BD4927

EF 4.5V BD4845 DG 2.6V BD4826 GF 4.5V BD4945 FG 2.6V BD4926

EE 4.4V BD4844 DF 2.5V BD4825 GE 4.4V BD4944 FF 2.5V BD4925

ED 4.3V BD4843 DE 2.4V BD4824 GD 4.3V BD4943 FE 2.4V BD4924

EC 4.2V BD4842 DD 2.3V BD4823 GC 4.2V BD4942 FD 2.3V BD4923

Part

Number

Marking

Detection

Voltage

Part

Number

Specifications Description

Output Circuit

Detection

Marking

Format

Voltage

Detection

Voltage

8：Open Drain Output
9：CMOS Output

Example: Displays VS over a 2.3V to 6.0V

range in 0.1V increments.

(2.9V is marked as “29”)

Part

Number

Marking

Detection

Voltage

Number

Part

2007.Apr.

●Absolute Maximum Rating (Ta=25℃)

Parameter Symbol Limits Unit

Power Supply Voltage VDD–GND -0.3 ~ +10 V

Output
Voltage

Power
Dissipation

Nch Open Drain Output GND -0.3 ~ +10

CMOS Output

SSOP5

VSOF5

*1
*3

*2
*3

VOUT

Pd

GND -0.3 ~ VDD +0.3

540

210

V

mW

Operating Temperature Topr -40 ~ +105 ℃

Ambient Storage Temperature Tstg -55 ~ +125 ℃

*1 Use above Ta=25℃ results in a 5.4mW loss per degree.
*2 Use above Ta=25℃ results in a 2.1mW loss per degree.

*3 When a ROHM standard circuit board (70mm×70mm×1.6mm glass epoxy board) is mounted.

●Electrical Characteristics (Unless specified otherwise, Ta=-40℃~+105℃)

Parameter Symbol Min. Typ. Max. Unit Conditions

Detection Voltage * VS VS(T) ×0.99 VS(T ) VS( T)×1.01 V V DD= H→L, RL=470kΩ

Detection Voltage

Temperature Coefficient

Hysteresis Voltage ∆VS

VS/∆T － ±100 － ppm/℃ Ta=-40 to +105℃ (Designed Guarantee)

VS×0.03 VS×0.05

VS×0.08 V VS ≧1.1V, RL=470kΩ, VDD=L→H→L

Circuit Current at ON * IDD1 － 0.66 1.98 µA VDD=VS-0.2V, VS=5.3～6.0V

Circuit Current at OFF * IDD2 － 0.9 2.7 µA VDD=VS+2.0V, VS=5.3～6.0V

Operating Voltage Range * VOPL 0.95 － － V VOL0.4V

“Low” Output Current (Nch) IOL 2 4 － mA VDS=0.5V, VDD=2.4V, VS=2.7V～6.0V

“High” Output Current (Pch) IOH 1.1 2.2 － mA VDS=0.5V, VDD=8.0V, VS=5.3V～6.0V

* Guarantee on Ta=25℃
Designed Guarantee. (Outgoing inspection is not done an all products.)

●Block Diagrams

BD48□□G/FVE

VDD

OUT

V

Vref

GND

Fig.1

TOP VIEW

SSOP5 VSOF5

PIN No. Symbol Function PIN No. Symbol Function

1 VOUT Reset Output 1 VOUT Reset Output

2 VDD Power Supply Voltage 2 SUB Substrate*

3 GND GND

4 N.C. Unconnected Terminal 4 GND GND

5 N.C.

Unconnected Terminal 5 VDD Power Supply Voltage

＊Connect the substrate to GND.

BD49□□G/FVE

3 N.C.

Vref

VDD

GND

Fig.2

TOP VIEW

Unconnected Terminal

VOUT

2/8

●Reference Data (Unless specified otherwise, Ta=25℃)

20

[mA]

OL

I

：

15

10

5

0

"LOW" OUTPUT CURRENT

0.0 0.5 1.0 1.5 2.0 2.5

DRAIN-SOURCE VOLTAGE ： V

[µA]

DD

I

：

2.0

BD4842G /FVE

【

】

1.5

1.0

0.5

CIRCUIT CURRENT

0.0
012345678910

V

SUPPLY VOLT AGE ：VDD[V]

DD

BD4842G /FVE

【

VDD=2.4V

VDD=1.2V

45

】

[mA]

40

OH

I

35

：

BD4942G /FVE

【

】

30

25

20

15

10

5

0

"HIGH" OUTPUT CURRENT

0123456

[V]

DS

DRAIN-SOURCE VOLTAGE ： V

VDD=8.0V

VDD=6.0V

VDD=4.8V

[V]

DS

OUT

：

1.5

A]

μ

[

DD1

I

：

1.0

Fig.3 Circuit Current

9

8

[V]

7

V

6

5

4

3

2

OUTPUT VOLTAGE

1

Ta=25

0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5

VDD SUPPLY VOLT AGE ：VDD[V]

℃

BD4842G /FVE

【

Ta=25

Fig.6 I/O Characteristics

BD4842G /FVE

【

Fig.4 “Low” Output Current

】

1.0

BD4842G/FVE

【

】

0.8

VOUT[V]

：

0.6

Fig.5 “High” Output Current

5.4

5.0

4.6

[V]

S

V

：

BD4842G/FVE

【

Low to High（VS+ΔVS）

】

4.2

℃

0.4

0.2

OUTPUT VOLTAGE

0.0

00.511.522.5

3.8

3.4
DETECTION VOLTAGE

～

～

3.0

-40 0 40 80

SUPPLY VOLTAGE ： [V]

Fig.7 Operating Limit Voltage

Fig.8 Detection Voltage

High to Low（VS）

TEMPERATURE ： Ta[℃]

Release Voltage

1.5

A]

μ

】

[

DD2

I

：

BD4842G /FVE

【

】

1.0

1.5

[V]

OPL

V

：

BD4842G /FVE

【

】

1.0

0.5

0.0

CIRCUIT CURRENT WHEN ON

-40 - 20 0 20 40 60 80 100

TEMPERATURE ： Ta[℃]

Fig.9 Circuit Current when ON

0.5

0.0

CIRCUIT CURRENT WHEN OFF

-40 - 20 0 20 40 60 80 100

TEMPERATURE ： Ta[℃]

Fig.10 Circuit Current when OFF

3/8

0.5

MINIMUM OPERATION VOLTAGE

0.0

-40 - 20 0 20 40 60 80 100

TEMPERATURE ： Ta[℃]

Fig.11 Operating Limit Voltage

●Reference Data

Examples of Leading (TPLH) and Falling (TPHL) Output

Part Number TPLH (µs) TPHL (µs)

BD4845G/FVE 39.5 87.8

BD4945G/FVE 32.4 52.4

VDD=4.3V→5.1V VDD=5.1V→4.3V

*This data is for reference only.

The figures will vary with the application, so please confirm actual operating conditions before use.

●Explanation of Operation

For both the open drain type (Fig. 12) and the CMOS output type (Fig. 13), the detection and release voltages are used as threshold voltages.

When the voltage applied to the VDD pins reaches the applicable threshold voltage, the VOUT terminal voltage switches from either “High” to

“Low” or from “Low” to “High”. Because the BD48□□G/FVE series uses an open drain output type, it is possible to connect a pull-up resistor to

VDD or another power supply [The output “High” voltage (VOUT) in this case becomes VDD or the voltage of the other power supply].

V

DD

Vref

R1

R2

Q1

R3

RL

Vref

V

OUT

GND

R1

R2

R3

Q2

Q1

DD

V

OUT

V

GND

Fig.12 (BD48□□ Type Internal Block Diagram) Fig.13 (BD49□□ Type Internal Block Diagram)

●Timing Waveform

Example: the following shows the relationship between the input voltages VDD and the output voltage VOUT when the input power supply

voltage VDD is made to sweep up and sweep down (the circuits are those in Fig. 12 and 13).

DD

V

DET

V

+ΔV

V

V

OPL

DET

DET

⑤

0V

OUT

V

OH

V

PLH

PHL

T

OL

V

①

②

PLH

T

PHL

T

③ ④

T

Fig.14

① When the power supply is turned on, the output is unsettled from after

over the operating limit voltage (VOPL) until TPHL. There fore it is

possible that the reset signal is not outputted when the rise time of

VDD is faster than TPHL.

② When VDD is greater than VOPL but less than the reset release

voltage (VS + ∆VS), the output voltages will switch to Low.

③ If VDD exceeds the reset release voltage (VS + ∆VS), then

switches from L to H.

④ If VDD 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 (∆VS). 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.

VOUT

4/8

●Circuit Applications

1）Examples of a common power supply detection reset circuit.

VDD1

BD48□□□

R

L

Microcontroller

CL

（Noise-filtering

Capacitor）

VDD2

GND

Fig.15 Open Collector Output Type

DD1

V

BD49

□□□

GND

Fig.16 CMOS Output Type

2) The following is an example of a circuit application in which an OR connection between two types of detection voltages resets the

microcontroller.

BD48□□□

When there are many power supplies of the system, power supplies VDD1 and VDD2 are being monitored separately, and it is necessary
to reset the microcomputer, it is possible to use an OR connection on the open drain output type BD48□□G/FVE series to pull-up to the

desired voltage (VDD3) as shown in Fig. 17 and make the output “High” voltage matches the power supply voltage VDD3 of the

microcontroller.

Microcontroller

L

C

(Noise-filtering

Capacitor

VDD2VDD1

）

BD48□□□

Fig.17

Application examples of BD48□□G/FVE series (Open Drain
output type) and BD49□□G/FVE series (CMOS output type) are

shown below.

CASE1: the power supply of the microcontroller (VDD2) differs

from the power supply of the reset detection (VDD1).
Use the open drain output type (BD48□□G/FVE) attached a

load resistance (RL) between the output and VDD2. (As shown

Figure 15)

CASE2: the power supply of the microcontroller (VDD1) is same

as the power supply of the reset detection (VDD1).
Use CMOS output type (BD49□□G/FVE) or open drain output
type (BD48□□G/FVE) attached a load resistance (RL) between

the output and Vdd1. (As shown Figure 16)

When a capacitance CL for noise filtering is connected to the

VOUT pin (the reset signal input terminal of the microcontroller),

please take into account the waveform of the rise and fall of the

output voltage (VOUT).

VDD3

L

R

Microcontroller

ST

R

GND

5/8

Examples of the power supply with resistor dividers

In applications where the power supply input terminal (VDD) of an IC with resistor dividers, it is possible that a through current will

momentarily flow into the circuit when the output logic switches, resulting in malfunctions (such as output oscillatory state).

(Through-current is a current that momentarily flows from the power supply (VDD) to ground (GND) when the output level switches from

“High” to “Low” or vice versa.)

A voltage drop of [the through-current (I1)] × [input resistor (R2)] is caused by the through current, and the input voltage to descends,

when the output switches from “Low” to “High”. When the input voltage decreases and falls below the detection voltage, the output voltage

switches from “High” to “Low”. At this time, the through-current stops flowing through output “Low”, and the voltage drop is eliminated. As a

result, the output switches from “Low” to “High”, which again causes the through current to flow and the voltage drop. This process is

repeated, resulting in oscillation.

V1

R2

I1

DD

V

R1

CIN

BD48□□□
BD49□□□

VOUT

GND

Fig.18

IDD

Through Current

DD

0

VDET

Fig.19 Current Consumption vs. Power Supply Voltage

V

6/8

z 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 . Electrical Characteristics

Be sure to check the electrical characteristics that are one the tentative specification will be changed by temperature, supply voltage, and

external circuit.

4 . Bypass Capacitor for Noise Rejection

Please put into the capacitor of 1µF or more between VDD

pin and GND, and the capacitor of about 1000pF between VOUT 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 VDD pin, Output pin and GND pin, or VDD 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 . Electromagnetic Field

Mal-function may happen when the device is used in the strong electromagnetic field.

7 . The VDD line inpedance might cause oscillation because of the detection current.

8 . A VDD -GND capacitor (as close connection as possible) should be used in high V

9 . Lower than the mininum input voltage makes the V

OUT high impedance, and it must be VDD in pull up (VDD) condition.

DD line impedance condition.

10. 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.

11. External parameters

The recommended parameter range for RL

is 10kΩ～1MΩ. There are many factors (board layout, etc) that can affect characteristics.

Please verify and confirm using practical applications.

12. Power on reset operation

Please note that the power on reset output varies with the VDD rise up time. Please verify the actual operation.

13. 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.

14. 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.

●Part Number Selection

B D 4 － T R

Standard CMOS Reset IC Reset Voltage Value Package Taping Specifications

BD48: Open Drain Type 23: 2.3V G: SSOP5 Embossed Taping

BD49: CMOS Output Type to (0.1V step) FVE: VSOF5

60: 6.0V

7/8

Q

y

Q

y

SSOP5

VSOF5

<Dimension>

2.8±0.2

1.25Max.

1.1±0.05

<Dimension>

+0.2

−0.1

1.6

0.05±0.05

1.0±0.05

2.9±0.2

5

12

0.95

1.6±0.05

1.6±0.05

1.2±0.05

0.5

0.6Max.

4

3

0.42

45

321

0.22±0.05

（Unit：mm）

°

+

6

°

4

°

−

4

0.2Min.

+0.05

0.13

−0.03

+0.05

−0.04

0.1

（Unit：mm）

0.2Max.

±0.05

0.13

M

0.08

<Tape and Reel information> SSOP5

Tape

uantit

Direction
of feed

Embossed carrier tape

3000pcs

TR (The direction is the 1pin of product is at the upper left
when you hold reel on the left hand and you pull out the
tape on the right hand)

Reel

※When you order , please order in times the amount of package quantity.

1Pin

<Tape and Reel information>

Tape

uantit

Direction
of feed

Embossed carrier tape

3000pcs

TR (The direction is the 1pin of product is at the upper left
when you hold reel on the left hand and you pull out the
tape on the right hand)

1Pin

Reel

※When you order , please order in times the amount of package quantity.

Direction of feed

Direction of feed

The contents described herein are correct as of October, 2005
The contents described herein are subject to change without notice. For updates of the latest information, please contact and confirm with ROHM CO.,LTD.
Any part of this application note must not be duplicated or copied without our permission.
Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding
upon circuit constants in the set.
Any data, including, but not limited to application circuit diagrams and information, described herein are intended only as illustrations of such devices and not as the specifications for such devices. ROHM CO.,LTD. disclaims any
warranty that any use of such devices shall be free from infringement of any third party's intellectual property rights or other proprietary rights, and further, assumes no liability of whatsoever nature in the event of any such
infringement, or arising from or connected with or related to the use of such devices.
Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or otherwise dispose of the same, implied right or license to practice or commercially exploit any intellectual property rights or other
proprietary rights owned or controlled by ROHM CO., LTD. is granted to any such buyer.
The products described herein utilize silicon as the main material.
The products described herein are not designed to be X ray proof.

Published by
Application Engineering Group

8/8

Appendix

Notes

No technical content pages of this document may be reproduced in any form or transmitted by any
means without prior permission of ROHM CO.,LTD.
The contents described herein are subject to change without notice. The specifications for the
product described in this document are for reference only. Upon actual use, therefore, please request
that specifications to be separately delivered.
Application circuit diagrams and circuit constants contained herein are shown as examples of standard
use and operation. Please pay careful attention to the peripheral conditions when designing circuits
and deciding upon circuit constants in the set.
Any data, including, but not limited to application circuit diagrams information, described herein
are intended only as illustrations of such devices and not as the specifications for such devices. ROHM
CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any
third party's intellectual property rights or other proprietary rights, and further, assumes no liability of
whatsoever nature in the event of any such infringement, or arising from or connected with or related
to the use of such devices.
Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or
otherwise dispose of the same, no express or implied right or license to practice or commercially
exploit any intellectual property rights or other proprietary rights owned or controlled by
ROHM CO., LTD. is granted to any such buyer.
Products listed in this document are no antiradiation design.

The products listed in this document are designed to be used with ordinary electronic equipment or devices
(such as audio visual equipment, office-automation equipment, communications devices, electrical
appliances and electronic toys).
Should you intend to use these products with equipment or devices which require an extremely high level
of reliability and the malfunction of which would directly endanger human life (such as medical
instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers
and other safety devices), please be sure to consult with our sales representative in advance.
It is our top priority to supply products with the utmost quality and reliability. However, there is always a chance
of failure due to unexpected factors. Therefore, please take into account the derating characteristics and allow
for sufficient safety features, such as extra margin, anti-flammability, and fail-safe measures when designing in
order to prevent possible accidents that may result in bodily harm or fire caused by component failure. ROHM
cannot be held responsible for any damages arising from the use of the products under conditions out of the
range of the specifications or due to non-compliance with the NOTES specified in this catalog.

Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact your nearest sales office.

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Appendix1-Rev2.0