STMicroelectronics STM1831 Datasheet
Reklama
Reklama
Features
■
■
■
■
■
■
■
■
■
■
Voltage monitored on separate sense input V
SEN
Factory-trimmed voltage thresholds in 100 mV increments from 1.6 V to 5.7 V
±2% voltage threshold accuracy
Operating voltage 1.6 V to 6.0 V
Open drain output
Low supply current of 0.8 µA (typ.)
Time delay programmable by external capacitor
Power supply transient immunity
Available in SOT23-5 package
Operating temperature –40 to 85 °C
Applications
■
■
■
■
Microprocessor reset circuitry
Charge voltage monitors
Memory battery backup switch circuits
Power failure detection circuits
STM1831
Voltage detector with sense input and external delay capacitor
SOT23-5
November 2010 Doc ID 18180 Rev 1 1/24 www.st.com
1
Contents
Contents
STM1831
Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2/24 Doc ID 18180 Rev 1
STM1831
List of tables
List of tables
Doc ID 18180 Rev 1 3/24
List of figures
List of figures
STM1831
Supply current vs. sense voltage, V
= 3.0 V, V
DET
= 2.0 V . . . . . . . . . . . . . . . . . . . . . . . 9
Supply current vs. input voltage, V
SEN
= 1.9 V (RST asserted) . . . . . . . . . . . . . . . . . . . . . . 9
Detect voltage vs. ambient temperature, V
= 2.4 V . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Detect voltage vs. supply voltage, V
DET
= 2.4 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Hysteresis voltage vs. ambient temperature, V
= 2.4 V . . . . . . . . . . . . . . . . . . . . . . . . 11
pin sink current vs. supply voltage, V
SEN
= 0 V, V
CD
= 0.5 V . . . . . . . . . . . . . . . . . . . . 11
Output voltage vs. sense voltage, V
= 2.4 V, T
A
= 25 °C, external pull-up resistor on RST is 100 k Ω , C
D
pin open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output voltage vs. supply voltage, V
SEN
= V
CC
, external pull-up resistor on RST is 100 k Ω , C
D
pin open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output current vs. supply voltage, V
SEN
= 0 V, V
RST
= 0.5 V. . . . . . . . . . . . . . . . . . . . . . . 13
Relative delay resistance vs. ambient temperature, V
= 5 V, V
SEN
= 6 V, V
CD
= 0 V . . 13
Release delay time vs. delay capacitance, T
A
= 25 °C. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Detect delay time vs. delay capacitance, T
= 25 °C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
RST output leakage current vs. ambient temperature,
V
CC
= V
SEN
= V
OUT
= 6.0 V, C
D
pin open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
RST output leakage current vs. output voltage, V
CC
= V
SEN
= 6.0 V,
T
A
= 85 °C, C
D
pin open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Sense current vs. supply voltage, V
= 1.9 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Sense current vs. ambient temperature, V
CC
= V
SEN
= 5 V . . . . . . . . . . . . . . . . . . . . . . . . 16
SOT23-5 - 5-lead small outline transistor package mechanical drawing . . . . . . . . . . . . . . 21
4/24 Doc ID 18180 Rev 1
STM1831
1 Description
Description
The STM1831 is a voltage detector with very low current consumption. It monitors a voltage on a separate input pin (V
SEN
), which is fully functional even if the monitored voltage goes down to 0 V. In addition, the delay of the output can be adjusted by an external capacitor.
Figure 1.
Logic diagram
VCC
VSEN
CD
STM1831 RST
VSS
AM00700
.
Table 1.
Pin
3
4
1
2
5
Pin descriptions
Type
Output open drain
Power
Power
Input
I/O
Name
RST
V
SS
V
CC
V
SEN
C
D
Function
Active-low reset output
Ground
Supply voltage
Sense voltage
Delay capacitor
Figure 2.
SOT23-5 pin connections (top view)
5 RST
VSS
VCC
1
2
3 4
CD
VSEN
AM00852
Doc ID 18180 Rev 1 5/24
Description STM1831
See
for a brief overview of the signals available on this device.
Power supply (V
CC
)
This pin is used to provide power to the device. A 0.1 µF decoupling ceramic capacitor is recommended to be connected between the V
CC device as possible.
and V
SS
pins, as close to the STM1831
Sense voltage input (V
SEN
)
Input voltage on this pin is monitored. When it drops below the threshold (V
DET
), reset output (RST) is asserted. If V
CC
is close to 0 V, internal logic disconnects the voltage divider from V
SEN
input in order to minimize I
SEN
current (see
and
).
Reset output (RST)
Reset output is asserted when the voltage on the V
SEN
input pin drops below the threshold
(V
DET
).
The STM1831 has an open drain, active-low output which sinks current when the output is asserted. Connect a pull-up resistor from RST to any supply voltage up to 6 V (see
Figure 4 ). Select a resistor value large enough to register a logic low, and small enough to
register a logic high, while all of the input current and leakage paths connected to the reset output line are being supplied. A 10 k Ω pull-up is sufficient in most applications.
The advantages of open drain output include the ability to connect more open drain outputs in parallel (wired OR connections) as well as connecting the output to a power supply voltage other than V
CC
.
Delay capacitor (C
D
)
Capacitor C
D
determines the delay (t
CD
) between reset deassertion and the moment when
V
SEN
voltage exceeds the V
DET
threshold (see
with calculations for more details).
Any external leakage due to poor quality timing capacitors or excessive humidity may cause a significant leakage current which extends the t
CD
timing. To minimize this effect, the PCB tracks between the C
D
pin and its respective timing capacitor should be as short as possible, properly covered with solder mask and isolated from other tracks (especially V
SS
) by as great a distance as possible. Low-leakage timing capacitors (ceramic or film capacitor) should be used.
Leave C
D
pin open if unused (i.e. t
CD
= 0 ms).
6/24 Doc ID 18180 Rev 1
STM1831
Figure 3.
Block diagram
Description
V
CC
V
SEN
Logic
R
1
R
2
R
3
V
REF
R
CD
RST
V
SS
C
D
AM00 8 5 3
Figure 4.
Application hookup
Monitored voltage
CD
VCC
VSEN
STM1831
CD
VSS
RST
R(1)
AM00699
1.
External pull-up resistor is needed for open drain RST output. A 10 k Ω is sufficient in most applications.
Doc ID 18180 Rev 1 7/24
Operation
2 Operation
STM1831
The STM1831 voltage detector monitors system voltages from 1.6 V to 5.7 V in 100 mV increments, has a voltage hysteresis (V
HYS
) and an output delay programmable by external capacitor C
D
.
The STM1831 asserts a reset output (RST) whenever V
CC
goes below the detect voltage
(V
DET
). The reset output stays asserted until V
CC
goes above the detect voltage with hysteresis (V
DET
+ V
HYS
). If the external capacitor is connected to the C
D
pin, the reset output deassertion is adequately delayed (see
with calculations below for more details). Leave the C
D
pin open if unused (i.e. t
CD
= 0 ms).
Figure 5.
Timing waveforms
VSEN
VDET + VHYST
VDET
CD
VTCD
RST
8/24 tDET tREL + tCD t t
DET
REL t
CD detect delay time release delay time (measured when external capacitor C
D
is disconnected) delay by external capacitor C
D
.
The t
CD
delay can be calculated based on
Equation 1 t
CD
= – R
CD
× C
D
×
–
V
--------------
V
CC
⎞
⎠ and considering R
CD
= 2 M Ω (typ.) and V
TCD
= 1.5 V (typ.) at V
CC
= 3.0 V:
Equation 2 t
CD
≅ 1.39
× 10
6 × C
D
( s F )
AM00854
Doc ID 18180 Rev 1
STM1831
3 Typical operating characteristics
Typical operating characteristics
Figure 6.
Supply current vs. sense voltage, V
CC
= 3.0 V, V
DET
= 2.0 V
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0 1 2 3 4
Sense voltage, V
SEN
(V)
5
TA = –40 °C
TA = 25 °C
TA = 85 °C
6
AM04965v1
Figure 7.
Supply current vs. input voltage, V
SEN
= 1.9 V (RST asserted)
1.2
1.0
0.8
0.6
0.4
0.2
0
0
2.0
1.8
1.6
1.4
1 5
TA = -40°C
TA = 25°C
TA = 85°C
2 3 4
Supply voltage, V
CC
(V)
6
AM04966v1
Doc ID 18180 Rev 1 9/24
Typical operating characteristics
Figure 8.
Detect voltage vs. ambient temperature, V
DET
= 2.4 V
2.50
2.45
2.40
2.35
V
CC
= 6.0 V
V
CC
= 1.6 V
STM1831
2.30
-40 -20 0 20 40
Ambient temperature, T
A
(°C)
60 80
AM04967v1
Figure 9.
Detect voltage vs. supply voltage, V
DET
= 2.4 V
2.50
2.45
T
A
= 85 °C
2.40
T
A
= 25 °C
T
A
= -40 °C
2.35
2.30
1 2 3 4
Supply voltage, V
CC
(V)
5 6
AM0496 8 v1
10/24 Doc ID 18180 Rev 1
STM1831 Typical operating characteristics
Figure 10.
Hysteresis voltage vs. ambient temperature, V
DET
= 2.4 V
300
250
200
150
100
50
0
-40
V
CC
= 6.0 V
V
CC
= 1.6 V
-20 0 20 40
Ambient Temperature, T
A
(°C)
60 80
AM04969v1
Figure 11.
C
D
pin sink current vs. supply voltage, V
SEN
= 0 V, V
CD
= 0.5 V
8
7
6
5
4
3
2
1
0
0 1 2 3 4
Supply voltage, V
CC
(V)
TA = -40 °C
TA = 25 °C
TA = 85 °C
5 6
AM04970v1
Doc ID 18180 Rev 1 11/24
Typical operating characteristics STM1831
Figure 12.
Output voltage vs. sense voltage, V
DET
= 2.4 V, T
A
= 25 °C, external pull-up resistor on RST is 100 k
Ω
, C
D
pin open
4
3
2
1
0
0
7
6
5
Vcc = 6.0 V
Vcc = 4.5 V
Vcc = 3.0 V
1 2 3
Sense voltage, V
SEN
(V)
4 5 6
AM04971v1
Figure 13.
Output voltage vs. supply voltage, V
SEN
= V
CC
, external pull-up resistor on RST is 100 k Ω, C
D
pin open
3.0
2.5
2.0
TA = -40 °C
TA = 25 °C
TA = 85 °C
1.5
1.0
0.5
0
0 0.5
2 2.5
1 1.5
Supply voltage, V
CC
(V)
AM04972v1
12/24 Doc ID 18180 Rev 1
STM1831 Typical operating characteristics
Figure 14.
Output current vs. supply voltage, V
SEN
= 0 V, V
RST
= 0.5 V
20
15
10
5
0
40
35
30
25
0 1 2 3 4
Supply voltage, V
CC
(V)
5
TA = -40 °C
TA = 25 °C
TA = 85 °C
6
AM0497 3 v1
Figure 15.
Relative delay resistance vs. ambient temperature, V
CC
= 5 V, V
SEN
= 6 V,
V
CD
= 0 V
1.30
1.20
1.10
1.00
0.90
0.80
0.70
-40 80 -20 0 20 40
Ambient temperature, T
A
(°C)
60
AM04974v1
Doc ID 18180 Rev 1 13/24
Typical operating characteristics
Figure 16.
Release delay time vs. delay capacitance, T
A
= 25 °C
10000
1000 Vcc = 1.6 V
Vcc = 3 V
Vcc = 6 V
100
10
1
0.1
0.0001
0.001
0.01
0.1
External delay capacitor, C
D
(µF)
Figure 17.
Detect delay time vs. delay capacitance, T
A
= 25 °C
10000
1000
Vcc = 1.6 V
Vcc = 3 V
Vcc = 6 V
100
10
1
0.0001
0.001
0.01
0.1
External delay capacitor, C
D
(µF)
1
1
STM1831
AM04975v1
AM04976v1
14/24 Doc ID 18180 Rev 1
STM1831 Typical operating characteristics
Figure 18.
RST output leakage current vs. ambient temperature,
V
CC
= V
SEN
= V
OUT
= 6.0 V, C
D
pin open
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-40 -20 0 20 40
Ambient temperature, T
A
(°C)
60 80
AM04977v1
Figure 19.
RST output leakage current vs. output voltage, V
CC
= V
SEN
= 6.0 V,
T
A
= 85 °C, C
D
pin open
0.6
0.5
0.4
0.3
0.2
0.1
0
0 5 6 1 2 3 4
Reset output voltage, V
RST
(V)
AM0497 8 v1
Doc ID 18180 Rev 1 15/24
Typical operating characteristics
Figure 20.
Sense current vs. supply voltage, V
SEN
= 1.9 V
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00
0 1 2 3 4
Supply voltage, V
CC
(V)
5
TA = -40 °C
TA = 25 °C
TA = 85 °C
6
STM1831
AM04979v1
Figure 21.
Sense current vs. ambient temperature, V
CC
= V
SEN
= 5 V
500
450
400
350
300
250
200
150
100
50
0
-40 -20 0 20 40
Ambient temperature, T
A
(°C)
60 80
AM049 8 0v1
16/24 Doc ID 18180 Rev 1
STM1831 Maximum ratings
Stressing the device above the ratings listed in Table 2 may cause permanent damage to
the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied.
Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Table 2.
Symbol
Absolute maximum ratings
Parameter Value
T
STG
T
SLD
(1)
V
CC
V
V
V
T
J
CD
RST
ESD
Storage temperature (V
CC
off)
Lead solder temperature for 10 seconds
Maximum junction temperature
Supply voltage
Delay capacitor pin voltage
Reset output voltage
– N-channel open drain
ESD voltage
– Human body model (MIL-STD-883, Method 3015)
– Machine model
–55 to 150
260
125
–0.3 to 7.0
–0.3 to V
CC
+ 0.3
–0.3 to 7.0
2000
200
1.
Reflow at peak temperature of 260 °C. The time above 255 °C must not exceed 30 seconds.
V
V
Unit
°C
°C
°C
V
V
Doc ID 18180 Rev 1 17/24
DC and AC parameters
5 DC and AC parameters
STM1831
This section summarizes the operating measurement conditions, and the DC and AC
characteristics of the device. The parameters in Table 4
that follow, are derived from tests performed under the measurement conditions summarized in
with measurement conditions for t
DET
and t
REL
. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters.
Table 3.
Operating and AC measurement conditions
Parameter Value
Supply voltage (V
CC
)
Ambient operating temperature (T
A
)
Input rise and fall times
Input pulse voltages
Input and output timing ref. voltages
1.6 to 6.0
–40 to 85
≤ 5
0.2 to 0.8 V
CC
0.3 to 0.7 V
CC
Unit
V
°C ns
V
V
Figure 22.
AC testing input/output waveforms
0.8 VCC
0.7 VCC
0.3 VCC
0.2 VCC
AI02568
18/24 Doc ID 18180 Rev 1
STM1831 DC and AC parameters
Table 4.
DC and AC characteristics
Symbol Parameter Conditions
(1)
Min. Typ. Max. Units
V
V
I
V
I
CC
DET
HYS
CC
RST
Operating voltage
Detect voltage
(2)
Hysteresis voltage
Supply current
Output current
–40 °C < T
A
< 85 °C 1.6
—
V
V
SEN
RST
= 0 V,
= 0.5 V
V
CC
= 1.6 V
V
CC
= 3.0 V
V
CC
= 6.0 V
V
CC
= 1.6 V
V
CC
= 2.0 V
V
CC
= 3.0 V
V
CC
= 4.0 V
V
CC
= 5.0 V
V
CC
= 6.0 V
V
CC
= 6.0 V, V
SEN
= 6.0 V,
V
RST
= 6.0 V, C
D
: open
V
DET
–2% V
DET
0.02 V
—
DET
0.05
V
DET
0.70
— 0.80
—
0.8
5.0
10.0
15.0
17.0
20.0
—
1.20
7.0
14.0
22.0
28.0
32.0
35.0
—
Δ V
DET
I
LEAK
/ ( Δ T
A
• V
DET
)
Output leakage current
Temperature variation
–40 °C < T
A
< 85 °C — ±100
I
SEN
R
CD
Sense current
Delay resistance
V
CC
= 0 V
V
CC
> 1.6 V, V
SEN
= 5.0 V
V
SEN
= 6.0 V, V
CC
= 5.0 V,
V
CD
= 0 V
—
—
1.4
10
300
2.0
I
CD
Delay capacitance pin sink current
V
CD
= 0.5 V, V
CC
= 1.6 V 0.2
1.4
V t t
TCD
DET
REL
Delay capacitance pin threshold voltage
Detect delay time
Release delay time
V
SEN
= 6.0 V, V
CC
= 1.6 V
V
SEN
= 6.0 V, V
CC
= 3.0 V
V
SEN
= 6.0 V, V
CC
= 6.0 V
V
CC
= 6.0 V, V
SEN
= 6.0 V →
0 V, C
D
: open
V
CC
= 6.0 V, V
SEN
= 0 V → 6
V, C
D
: open
0.70
1.25
2.45
—
—
0.85
1.50
2.65
40
55
1.
Valid for ambient operating temperature: T
A
= 25 °C; V
CC
= 1.6 V to 6.0 V (except where noted).
2.
Factory-trimmed voltage thresholds in 100 mV increments from 1.6 V to 5.7 V.
6.0
V
DET
+ 2%
0.08 V
1.20
1.40
2.00
—
—
—
—
—
—
400
—
—
500
2.6
—
1.00
1.70
2.85
75
170
DET
V
V
V
µA
mA
nA
ppm/ °C nA
M Ω
mA
V
µs
µs
Doc ID 18180 Rev 1 19/24
Package mechanical data
6 Package mechanical data
STM1831
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
®
packages, depending on their level of environmental compliance. ECOPACK
® specifications, grade definitions and product status are available at: www.st.com
.
ECOPACK
®
is an ST trademark.
The maximum ratings related to soldering conditions are also marked on the inner box label.
20/24 Doc ID 18180 Rev 1
STM1831 Package mechanical data
Figure 23.
SOT23-5 - 5-lead small outline transistor package mechanical drawing
E
A1
1 e e1 D
5 x b 5x
0.10 C
A2
A
Note:
C
T
E1 L
01 33 77 8 _C
Drawing is not to scale.
D
E b c
A
A1
A2
E1 e e1
L
θ
N
Table 5.
Symbol
2.90
2.80
1.60
0.95
1.90
0.45
4
SOT23-5 - 5-lead small outline transistor package mechanical data
Millimeters Inches
Note
Typ.
Min.
Max.
Typ.
Min.
Max.
1.15
0.00
0.90
0.30
0.08
1.45
0.15
1.30
0.50
0.22
0.045
0.00
0.035
0.012
0.003
0.057
0.006
0.051
0.020
0.009
0.30
0
5
0.60
8
0.114
0.110
0.063
0.037
0.075
0.018
4
0.012
0
5
0.024
8 Degrees
Doc ID 18180 Rev 1 21/24
Part numbering STM1831
Table 6.
Example:
STM1831 ordering information scheme
STM1831 L 24 WY 6
Device type
STM1831
Reset output polarity
L: active-low
Detector threshold
(1)
24: 2.4 V typ.
(100 mV steps from 1.6 V to 5.7 V available)
Package
WY: SOT23-5
Temperature range
6: –40 °C to +85 °C
Shipping method
F: Lead-free ECOPACK
® package, tape and reel
1.
Other detector thresholds are offered. Minimum order quantities may apply. Contact local ST sales office for availability.
F
22/24 Doc ID 18180 Rev 1
STM1831
Table 7.
Date
Document revision history
Revision
16-Nov-2010 1 Initial release.
Changes
Revision history
Doc ID 18180 Rev 1 23/24
STM1831
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Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
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© 2010 STMicroelectronics - All rights reserved
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24/24 Doc ID 18180 Rev 1
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