RichTek RT9818 Technical data

查询RT9818A-49GU3供应商

Micro-Power Voltage Detectors

RT9818

General Description

The RT9818 is a micro-power voltage detector
supervising the power supply voltage level for
microprocessors (μP) or digital systems. It provides
internally fixed threshold levels with 0.1V per step ra nging
from 1.2V to 5V , which covers most digital applications. It
features low supply current of 3μA. The RT9818 performs
supervisory function by sending out a reset signal
whenever the V
level. This reset signal will last the whole period before
VDD recovering. Once VDD recovered upcrossing the
threshold level, the reset signal will be released after a

certain delay time. RT9818 is provided in SC-82, SC-70-3,

voltage falls below a preset threshold

DD

Features

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z Internally Fixed Threshold 1.2V to 5V in 0.1V Step

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z High Accuracy

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z Low Supply Current 3

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z No External Components Required

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z Quick Reset within 20

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z Built-in Recovery Delay Include 0ms, 55ms, 220ms,

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450ms Options

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z Low Functional Supply Voltage 0.9V

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z N-Channel Open-Drain Output

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z Small SC-82, SC-70-3, SOT-23-3, SOT-23-5, SOT-89

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Packages

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z RoHS Compliant and 100% Lead (Pb)-Free

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±±

±1.5%

±±

μμ

μA

μμ

μμ

μs

μμ

SOT-23-3, SOT -23-5 and SOT -89 packages.

Applications

Ordering Information

RT9818

DS9818-05 March 2007 www.richtek.com

­Package Type
U3 : SC-70-3
V : SOT-23-3
VL : SOT-23-3 (L-Type)
B : SOT-23-5
X : SOT-89
Y : SC-82
YR : SC-82 (R-Type)

Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer­ cial Standard)

Threshold Voltage
12 : 1.2V
13 : 1.3V
:
49 : 4.9V
50 : 5.0V

Reset Active Timeout Period
A = 0ms

(RESET)

B = 55ms (RESET)
C = 220ms (RESET)
D = 450ms (RESET)
E = 0ms (RESET)
F = 55ms (RESET)
G = 220ms (RESET)
H = 450ms (RESET)

z Computers
z Controllers
z Intelligent Instruments
z Critical μP and μC Power Monitoring
z Portable/Battery-Powered Equipment

Marking Information

For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.

Typical Application Circuit

100k

Pull Up

VDD

μP

RESET/

RESET

Note :
RichTek Pb-free and Green products are :

`RoHS compliant and compatible with the current require­ ments of IPC/JEDEC J-STD-020.

`Suitable for use in SnPb or Pb-free soldering processes.
`100%matte tin (Sn) plating.

RT9818

GND

VDD

RESET/
RESET

1

RT9818

Pin Configurations

(TOP VIEW)

GND NC

4

1

RESET/

RESET

SC-82

5

RESET/

RESET

SOT-23-5

3

2

VDD

2

GNDVDD

RESET/

RESET

4

1

VDD

NC

3

2

GND

SC-82 (R-Type)

NCNC

4

31

RESET/

RESET

231

SOT-89

Functional Pin Description

VDD

3

1

GND

2

RESET/

RESET

SOT-23-3 (L-Type)

1

GND

VDD

3

RESET/

RESET

SC-70-3

VDD

3

2

1

RESET/

RESET

2

GND

SOT-23-3

Note : There is no pin1 indicator on top mark for SC-82 type,
and pin 1 will be lower left pin when reading top mark from
left to right. Pin2 of SC-82 is wider than other pins.

GNDVDD

Pin Name Pin Function

GND Ground

RESET Active Low Open-Drain Reset Output
RESET Active High Open-Drain Reset Output
VDD Power Pin

Function Block Diagram

VDD

VSET

Threshold

Voltage Setting

CMP

POR

Power On Reset

Timer

RESET/

RESET

N MOS

GND

DS9818-05 March 2007www.richtek.com

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RT9818

Absolute Maximum Ratings (Note 1)

z T erminal V oltage (with Respe ct to GND)

VDD------------------------------------------------------------------------------------------------------------------------ −0.3V to 6.0V

z All Other Inputs -------------------------------------------------------------------------------------------------------- −0.3V to V
z Input Current, I
z Power Dissipation, P

----------------------------------------------------------------------------------------------------- 20mA

VDD

@ TA = 25°C

D

SC-70 / SC-82---------------------------------------------------------------------------------------------------------- 0.25W
SOT-23-3 ---------------------------------------------------------------------------------------------------------------- 0.4W
SOT-23-5 ---------------------------------------------------------------------------------------------------------------- 0.4W

SOT-89------------------------------------------------------------------------------------------------------------------- 0.55W

z Package Thermal Resistance (Note 4)

SC-70 / SC-82, θJA---------------------------------------------------------------------------------------------------- 400°C/W
SOT-23-3, θJA----------------------------------------------------------------------------------------------------------- 250°C/W
SOT-23-5, θJA----------------------------------------------------------------------------------------------------------- 250°C/W

SOT-89, θJA------------------------------------------------------------------------------------------------------------- 180°C/W

z Lead Temperature (Soldering, 10sec.)---------------------------------------------------------------------------- 260°C
z Storage T emperature Range ---------------------------------------------------------------------------------------- −65°C to 125°C
z ESD Susceptibility (Note 2)

HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Ma chine Mode)-------------------------------------------------------------------------------------------------- 200V

DD

+0.3V

Recommended Operating Conditions (Note 3)

z Junction T emperature Range---------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient T emperature Range---------------------------------------------------------------------------------------- −40°C to 85°C

Electrical Characteristics

(VDD = 3V, unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Units

Operating VDD (V

) Range VDD 0.9 -- 6

OUT

Supply Current IDD VTH = 3V , VDD = 4.5V TA = 27°C -- 3 8
Reset Threshold VTH TA = 27°C -- 1.2 to 5.0 --
Th reshold Voltage Accuracy ΔVTH T

= 27°C −1.5 -- +1.5 %

A

VDD Drop to Reset Delay tRD Drop = VTH -125mV -- 20 -- μs

-- 0 --

Reset Active Time
Out Period

RT9818A/E
RT9818B/F 35 55 75

VDD ≥ 1.02×VTH

t

RT9818C/G 143 220 297

RP

RT9818D/H 292 450 608
RESET Output Voltage Low (Note 5) VOL 3 = VDD < VTH I
Hysteresis Width V

0.01VTH V

HYS

>3.5 mA -- -- 0.4 V

SINK

V
μA
V

ms

DS9818-05 March 2007 www.richtek.com

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RT9818

Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are

for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.

Note 2. Devices are ESD sensitive. Handling precaution recommended.
Note 3. The device is not guaranteed to function outside its operating conditions.

Note 4. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of

JEDEC 51-3 thermal measurement standard.

Note 5. The voltage VOL can be calculated by VOL = VDD − Ir * R. Where R is the pull-up resistor and Ir is the current flowing

through the pull-up resistor. For typical application (R=100kΩ), V

is less than 0.2V.

OL

DS9818-05 March 2007www.richtek.com

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Typical Operating Characteristics

)

)

)

)

)

RT9818

Nch Driver Output Current vs. V

2.4

RT9818A-12

2

1.6

1.2

V

0.8

Output Current (mA

0.4

0

0 0.3 0.6 0.9 1.2 1.5

DD

V

DD

= 1.0V

DS

= 1.1V

VDS (V)

Nch Driver Output Current vs. V

120

RT9818A-45

100

80

60

40

Output Current (mA

20

0

012345

VDD = 4.4V
= 4.0V
= 3.5V
= 3.0V
= 2.5V
= 2.0V
= 1.5V

DS

VDS (V)

Nch Driver Output Current vs. V

60

RT9818C-30

50

V

V

DD

DD

= 2.0V

40

30

20

Output Current (mA

10

0

0 0.5 1 1.5 2 2.5 3 3.5

V

DD

= 1.5V

V

DD

= 2.5V

DS

= 2.8V

VDS (V)

Output Voltage vs. Input Voltage

7

RT9818

6

5

4

3

2

Output Volgate ( V)

1

0

0123456

1.2V

Inpu t Volgate ( V )

4.5V

Supply Current v s . Input Voltage

6

RT9818A-12

5

4

3

2

Supply Cur rent ( uA

1

0

0123456

80°C

25°C

-30°C

Inp ut Voltage (V)

4

3.5
3

2.5
2

1.5
1

Supply Cur rent (uA

0.5
0

Supply Current v s . Input Voltage

RT9818C-30

80°C

25°C

-30°C

0123456

Inp ut Voltage (V)

DS9818-05 March 2007 www.richtek.com

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