AIC811/AIC812
Reset Circuits with Manual Reset Input
Analog Integrations Corporation
Si-Soft Research Center
DS-811P-03 010405
3A1, No.1, Li-Hsin Rd. I, Science Park, Hsinchu 300, Taiwan, R.O.C.
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
1
FEATURES
Ultra Low Supply Current 1
A(typ.)
Guaranteed Reset Valid to Vcc=0.9V
Available in two Output Types: Push-Pull Active
Low (AIC811), Push-Pull Active High (AIC812)
140ms Min. Power-On Reset Pulse Width
Internally Fixed Threshold 2.3V, 2.6V, 2.9V,
3.1V, 4.0V, 4.4V, and 4.6V
Tight Voltage Threshold Tolerance: 1.5%
Low profile Package: SOT-23-5
APPLICATIONS
Notebook Computers
Digital Still Cameras
PDAs
Critical Microprocessor Monitoring
DESCRIPTION
AIC811/AIC812 are low-power microprocessor (P)
supervisory circuits used to monitor power supplies in
P and digital systems. They provide applications with
benefits of circuit reliability and low cost by eliminating
external components. AIC811/AIC812 also offer a
manual reset input.
These devices perform as valid singles in applications
with Vcc ranging from 6.0V down to 0.9V. The reset
signal lasts for a minimum period of 140ms whenever
V
CC
supply voltage falls below preset threshold. Both
AIC811 and AIC812 were designed with a reset
comparator to help identify invalid signals, which last
less than 140ms. The only difference between them is
that they have an active-low
RESET
output and
active-high RESET output, respectively.
Low supply current (1
A)
makes AIC811/AIC812 ideal
for portable equipment. The devices are
available
in
SOT-23-5 package.
TYPICAL APPLICATION CIRCUIT
VCC
VCC
GND
GND
P
RESET
INPUT
RESET
(RESET)
MR
V
CC
AIC811
(AIC812)
Pushbutton
Switch
AIC811/AIC812
ORDERING INFORMATION
3
2
1
4
5
AIC811-XXXXXX
AIC812-XXXXXX
(Additional voltage versions with a unit of 0.1V within the voltage range from 1.5V to 5.5V for this
product line may be available on demand with prior consultation with AIC.)
Example: AIC811-31CVTR
3.1V version, in SOT-23-5 Package & Tape & Reel Packing Type
AIC811-31PVTR
3.1V version, in Lead Free SOT-23-5 Package & Tape & Reel Packing Type
PIN CONFIGURATION
SOT-23-5
TOP VIEW
1: GND
2: NC
3: RESET (RESET)
4: MR
5: VCC
PACKING TYPE
TR: TAPE & REEL
BG: BAG
PACKAGE TYPE
V: SOT-23-5
C: COMMERCIAL
P: LEAD FREE COMMERCIAL
RESET THRESHOLD VOLTAGE
23: 2.3V
26: 2.6V
29: 2.9V
31: 3.1V
40: 4.0V
44: 4.4V
46: 4.6V
SOT-23-5 Marking
Part No.
Marking
Part No.
Marking
AIC811-23CV BQ23
AIC812-23CV BR23
AIC811-26CV
BQ26
AIC812-26CV
BR26
AIC811-29CV BQ29
AIC812-29CV BR29
AIC811-31CV BQ31
AIC812-31CV BR31
AIC811-40CV BQ40
AIC812-40CV BR40
AIC811-44CV BQ44
AIC812-44CV BR44
AIC811-46CV BQ46
AIC812-46CV BR46
2
AIC811/AIC812
Part No.
Marking
Part No.
Marking
AIC811-23PV BQ23P
AIC812-23PV BR23P
AIC811-26PV
BQ26P
AIC812-26PV
BR26P
AIC811-29PV BQ29P
AIC812-29PV BR29P
AIC811-31PV BQ31P
AIC812-31PV BR31P
AIC811-40PV BQ40P
AIC812-40PV BR40P
AIC811-44PV BQ44P
AIC812-44PV BR44P
AIC811-46PV BQ46P
AIC812-46PV BR46P
ABSOLUTE MAXIMUM RATINGS
V
CC
-0.3V ~6.5V
RESET, RESET
-0.3V ~ (VCC+0.3V)
Input Current (V
CC
,
MR
)
20mA
Output Current (RESET or
RESET
)
20mA
Continuous Power Dissipation (T
A
= +70
C)
320mW
Operating Junction Temperature Range
-40
C ~ 85C
Junction Temperature
125
C
Storage Temperature Range
- 65
C ~ 150C
Lead Temperature (Soldering) 10 sec
260
C
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
TEST CIRCUIT
VCC
5
GND
1
NC
2
RESET
3
MR
4
AIC811
Vin
Iin
Pushbuttom
Switch
3
AIC811/AIC812
ELECTRICAL CHARACTERISTICS
4
(Typical values are at T
A
=25
C, unless otherwise specified) (Note 1)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
Operating Voltage Range
V
CC
0.9
6
V
Supply Current
I
CC
V
CC
= V
TH
+0.1V
1
3
A
T
A
=+25
C 2.265
2.3
2.335
AIC811-23
T
A
= -40
C to +85C
2.254
2.346
T
A
=+25
C 2.561
2.6
2.639
AIC811-26
T
A
= -40
C to +85C 2.548 2.652
T
A
=+25
C 2.857
2.9
2.944
AIC811-29
T
A
= -40
C to +85C 2.842 2.958
T
A
=+25
C 3.054
3.1
3.147
AIC811-31
T
A
= -40
C to +85C 3.038 3.162
T
A
=+25
C 3.940
4.0
4.060
AIC811-40
T
A
= -40
C to +85C 3.920 4.080
T
A
=+25
C 4.334
4.4
4.466
AIC811-44
T
A
= -40
C to +85C 4.312 4.488
T
A
=+25
C 4.531
4.6
4.669
Reset Threshold
V
TH
AIC811-46
T
A
=-40
C to +85C 4.508 4.692
V
V
CC
to Reset Delay
T
RD
V
CC
=V
TH
to (V
TH
0.1V),
V
TH
=3.1V
20
S
T
A
=+25
C
140 230 560
Reset Active Timeout Period
T
RP
V
CC
= V
TH(MAX)
T
A
= -40
C to +85C 100 1030
mS
MR
to Reset Propagation
Delay
T
MD
Vcc=6V
0.5
S
V
IH
0.7V
CC
MR
Input Threshold
V
IL
0.25V
CC
V
MR
Pull-Up
Resistance
10 20 30 K
V
OH
V
CC
=V
TH
+0.1V, I
SOURCE
=1mA 0.8V
CC
RESET
Output Voltage
V
OL
V
CC
=V
TH
- 0.1V, I
SINK
=1mA
0.2Vcc
V
V
OH
V
CC
=V
TH
+0.1V, I
SOURCE
=1mA 0.8V
CC
RESET Output Voltage
V
OL
V
CC
=V
TH
- 0.1V, I
SINK
=1mA
0.2Vcc
V
Note1: Specifications are production tested at T
A
=25
C. Specifications over the -40C to 85C operating
temperature range are assured by design, characterization and correlation with Statistical Quality
Controls (SQC).
Note2:
RESET
output is for AIC811; RESET output is for AIC812.
AIC811/AIC812
TYPICAL PERFORMANCE CHARACTERISTICS
5
-40
-
20
0
20
40
60
80
100
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
V
TH
=2.3V
V
TH
=3.1V
V
TH
=4.6V
Su
pp
l
y
Cu
r
r
ent
(
A
)
Temperature (
C)
Fig 1 Supply Current vs. Temperature
P
o
w
e
r-Dow
n R
e
set Delay
(
S)
Fig 2 Power-Down Reset Delay vs. Temperature
-60
-40
-20
0
20
40
60
80
100
0
10
20
30
40
50
60
70
80
90
100
110
120
V
OD
=200mV
V
OD
=100mV
V
OD
=50mV
Temperature (
C)
V
TH
=2.3V
V
OD
=V
TH
-V
CC
P
o
w
e
r-Dow
n R
e
set Delay
(
S)
Temperature (
C)
Fig 3 Power-Down Reset Delay vs. Temperature
-
60
-
40
-20
0
20
40
60
80
100
0
20
40
60
80
100
120
140
160
180
200
220
240
V
OD
=200mV
V
OD
=100mV
V
OD
=50mV
V
TH
=3.1V
V
OD
=V
TH
-V
CC
P
o
w
e
r-Dow
n R
e
set Delay
(
S)
Temperature (
C)
Fig 4 Power-Down Reset Delay vs. Temperature
-60
-
40
-
20
0
20
40
60
80
100
0
100
200
300
400
V
OD
=200mV
V
OD
=100mV
V
OD
=50mV
V
TH
=4.6V
V
OD
=V
TH
-V
CC
N
o
r
m
aliz
ed
R
e
s
e
t
T
h
r
e
s
h
old
(
V
)
Temperature (
C)
Fig 5 Normalized Reset Threshold vs. Temperature
-40
-20
0
20
40
60
80
100
0.985
0.990
0.995
1.000
1.005
1.010
1.015
V
TH
=3.1V
V
TH
=2.3V
V
TH
=4.6V
Power
-
Up Res
e
t
T
i
meout
(
m
S)
Temperature (
C)
Fig 6 Power-Up Reset Timeout vs. Temperature
-60
-40
-20
0
20
40
60
80
100
0
100
200
300
400
500
600
V
TH
=2.3V
V
TH
=3.1V
V
TH
=4.6V
AIC811/AIC812
BLOCK DIAGRAM
6
R
PULL_UP
20K
R2
R1
MR
GND
RESET
(RESET)
Reset Generator
-
+
Bandgap
VCC
PIN DESCRIPTIONS
GND Pin
: Ground.
RESET
Pin (AIC811) : Active low output pin.
RESET
Output remains low while Vcc below reset
threshold.
RESET Pin (AIC812) : Active high output pin. RESET output remains high while Vcc below reset
threshold.
MR
Pin
: Logic low manual reset input. This active-low input has an internal 20k
pull-up
resistor. It can be driven by a TTL or CMOS, or shorted to ground with a switch.
Leave open when unused.
Vcc Pin
: Supply voltage.
DETAILED DESCRIPTIONS OF TECHNICAL TERMS
If a brownout condition occurs (VCC drops below
the reset threshold),
RESET
goes low. Any time
VCC goes below the reset threshold, the internal
timer resets to zero, and
RESET
goes low. The
internal timer is activated after VCC returns
above the reset threshold, and
RESET
remains
low for the reset timeout period.
RESET OUTPUT
P will be activated at a valid reset state. These
P supervisory circuits assert reset to prevent
code execution errors during power-up,
power-down, or brownout conditions.
RESET
is guaranteed to be a logic low for
V
TH
>VCC>0.9V. Once VCC exceeds the reset
threshold, an internal timer keeps
RESET
low
for the reset timeout period; after this interval,
RESET
goes high.
The manual reset input (
MR
) can also initiate a
reset. AIC812 has an active-high RESET output
that is the inverse of AIC811's
RESET
output.
AIC811/AIC812
MANUAL RESET INPUT
Many P-based products require manual reset
capability, allowing operators, test technicians, or
external logic circuitry to initiate a reset. Logic low
on
MR
asserts reset. Reset will remain asserted
for the Reset Active Timeout Period (t
RP
) after
MR
returns high. This input has an internal 20K
pull-up resistor, so it can be floating if it is not used.
MR
can be driven with TTL or CMOS-logic levels,
or with open-drain/collector outputs. Another
alternative is to connect a normal switch from
MR
to GND to create a manual reset function.
Connecting a 0.1F capacitor from
MR
to ground
can provide noise immunity to prevent noise caused
by long cables of
MR
or noisy environment.
BENEFITS OF HIGHLY ACCURATE RESET
THRESHOLD
AIC811/812 with specified voltage as 5V10% or
3V10% are ideal for systems using a 5V5% or 3V
5% power supply. The reset is guaranteed to
assert after the power supply falls out of regulation,
but before power drops below the minimum
specified operating voltage range of the system ICs.
The pre-trimmed thresholds are reducing the range
over which an undesirable reset may occur.
APPLICATION INFORMATION
NEGATIVE-GOING VCC TRANSIENTS
In addition to issuing a reset to the P during
power-up, power-down, and brownout conditions,
AIC811 series are relatively resistant to
short-duration negative-going VCC transient.
ENSURING A VALID RESET OUTPUT DOWN
TO VCC=0
When VCC falls below 0.9V, AIC811
RESET
output no longer sinks current; it becomes an open
circuit. In this case, high-impedance CMOS logic
inputs connecting to
RESET
can drift to
undetermined voltages. Therefore, AIC811/2 with
CMOS is perfect for most applications of VCC
below 0.9V. However in applications where
RESET
must be valid down to 0V, adding a
pull-down resistor to
RESET
causes any leakage
currents to flow to ground, holding
RESET
low.
INTERFACING TO P WITH BIDIRECTIONAL
RESET PINS
Ps with bidirectional reset pins can contend with
AIC811/812 reset outputs. If AIC811
RESET
output is asserted high and the P wants to pull it
low, indeterminate logic levels may occur. To
correct such cases, connect a resistor between
AIC811
RESET
(or AIC812 RESET) output and
theP reset I/O. Buffer the reset output to other
system components.
7
AIC811/AIC812
c
A
A2
b
WITH PLATING
0.
25
A1
SECTION A-A
BASE METAL
e1
D
E
A
A
E1
SEE VIEW B
e
0
0.90
0.30
1.50
2.60
2.80
0.08
0.30
0.05
e
L1
L
e1
c
E
E1
D
b
A2
A1
0.95 BSC
8
0.60
1.90 BSC
0.60 REF
1.30
1.70
3.00
3.00
0.22
0.50
0.15
0.95
MIN.
S
Y
M
B
O
L
A
1.
MAX.
SOT-25
MILLIMETERS
8
PHYSICAL DIMENSIONS
(unit: mm)
SOT-23-5
45
Note:
Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry
other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third parties that may
result from its use. We reserve the right to change the circuitry and specifications without notice.
Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices or
systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure
to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in
a significant injury to the user.
VIEW B
L
SEATING PLANE
GAUGE PLANE
L1
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