AS1923A-BSTT-I [AMSCO]
Quad-Voltage Microprocessor Supervisory Circuit; 四路电压微处理器监控电路
| 型号： | AS1923A-BSTT-I |
| 厂家： | 
AMS(艾迈斯) |
| 描述： | Quad-Voltage Microprocessor Supervisory Circuit |
| 文件： | 总17页 (文件大小：864K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
austriamicrosystems AG
is now
ams AG
The technical content of this austriamicrosystems datasheet is still valid.
Contact information:
Headquarters:
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
e-Mail: ams_sales@ams.com
Please visit our website at www.ams.com
Datasheet
AS1923
Quad-Voltage Microprocessor Supervisory Circuit
1 General Description
The AS1923 microprocessor supervisory circuit was designed to
monitor up to four system supply voltages without the need for exter-
nal components, and asserts a single reset if any of the monitored
supply voltages drops below its reset threshold.
2 Key Features
ꢀ
Simultaneous Quad-Voltage Monitoring
ꢀ
Precision Factory-Trimmed Reset Threshold Options: +5.0,
+3.3, +3.0, +2.5, +1.8, and -5.0V
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
User-Adjustable Voltage Monitoring Threshold Options
Low Supply Current: 55µA
The AS1923 features an active-low reset output that is asserted
when any of the 4 monitored voltages are below their respective
reset threshold. The reset output is open-drain with a weak internal
pullup (10µA) to IN2. Reset remains low for a specified reset timeout
period (120ms min) after all voltages have stabilized. The output is
valid as long as the IN1 or IN2 input voltage remains >1V.
Open-Drain – AS1923A
10µA Current Source Pullup – AS1923B
Reset Timeout Period: 120ms
Minimal external component requirements, small size, and wide tem-
perature range (-40 to +85°C) greatly improves reliability compared
to individual supervisory circuits or discrete components.
RESET Valid to IN1 = 1V or IN2 = 1V
Immune to Fast INx Transients
ExternaComponents not Required
A wide range of factory-trimmed threshold voltages are available to
accommodate many different supply voltages/tolerances with mini-
mal external component requirements.
Garanteed Performance: Operatg Temperature Range = -40
to +85ºC
Factory-trimmed options are available for monitoring +5.0, +3.3,
+3.0, +2.5, +1.8, and -5.0V supplies with -5% and/or -10% toler-
ances. The device is also available with one or two user-adjutable
threshold options (via external resistor-divider network) if non-stan-
dard voltage thresholds are required.
ꢀ
6-pin SOT23 Package
The AS1923 is available in an 6-pin SOT23 package.
3 Applications
The device is ideal for portable and battery-powered systems,
embedded controllers, intelligent instruments, automotive systems,
critical CPU monitoring, and any multi-supply application.
Figure 1. AS1923 - Typical Application
4
Monitoring
Voltage 1
IN
5
Motorin
Voltae 2
3
IN2
CPU
AS1923
RESETN RESETN
6
Monitoring
Voltage 3
IN3
1
Monitoring
Voltage 4
IN4
GND
2
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
1 - 16
AS1923
Datasheet - Pinout
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
IN4
GND
1
2
3
6
5
4
IN3
IN2
IN1
AS1923
RESETN
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
IN4
Description
Input Voltage 4. See Ordering Informatioon page 14 for monitoed voltages.
1
2
Ground
GND
Reset Output. AS1923A see Ordering Information oge 4) supports an external pullup resistor; AS1923B
contains an internal 1µA curent source pullupESETN goes low (reset asserted) when any one of the INx
voltages goes bew its pecified threshold. Ater all uts have stabilized, RESETN remains low for at least
120ms (min) bfore oing high.
3
RESETN
Input VoltagSee Ordering Inforn on page 14 for monitored voltages.
4
5
6
IN1
IN2
IN3
Input Voltage 2. See Ordering Infoon page 14 for monitored voltages.
Note: IN2 is the power suply input for the AS1923.
Input Voltage 3. See Ordering Information on page 14 for monitored voltages.
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
2 - 16
AS1923
Datasheet - Absolute Maximum Ratings
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Min
Max Units
Comments
Electrical Parameters
IN1, IN2 (Monitored Voltage), IN3, IN4 to GND
-0.3
-7
+7
+0.3
+6
V
V
V
IN4 to GND (Device Variants M, N, O, and P, see Table 5
on page 14)
RESETN to GND
Latchup immunity
-0.3
Class I Level A in accordance with EIA/JEDE8
Continuous Power Dissipation
Continuous Power Dissipation
696
mW
Derate 8.7mW/ºC above +70ºC
(TAMB = +70ºC)
Temperature Ranges and Storage Conditions
Junction Temperature
+150
0
ºC
ºC
Storage Temperature Range
-55
The relw peak soldering temperature (body
temperature) spifed is in accordance with IPC/JEDEC
J-STD-20 “oisture/Reflow Sensitivity Classification for
Nonermetic Solid State Surface Mount Devices”.
ead nish for Pb-free leaded packages is matte tin
(100% Sn).
Package Body Temperature
+260
85
ºC
%
Humidity non-condensing
Moisture Sensitive Level
5
1
Represents a max. floor life time of unlimited
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
3 - 16
AS1923
Datasheet - Electrical Characteristics
6 Electrical Characteristics
VIN2 = +1V to +5.5V, Typ values @ VIN2 = +3.0V to +3.3V, TAMB = +25ºC (unless otherwise specified).
Table 3. Electrical Characteristics
Parameter 1
Symbol
Tamb
Conditions
Min
-40
1.0
Typ
Max
85
Units
°C
Operating Temperature Range
2, 3
VIN2
5.5
V
Supply Voltage Range
VINx = Input Threshold Voltage (Input Threshold
25
55
40
Voltage of 1.8, 2.5, or 5V)
VIN2 = Input Threshold Voltage (Input Threshold
115
Voltage of 3.0 or 3.3V) 4
IINx
Input Current
µA
VINx = 0 to VIN2
-0.1
0.1
(Input Threshold Voltage = +1.23V) 5
VIN1 = 1.5V (AS1923 K/L only)
VINx = -5V (Input Threshold Voltage = -5V)
VINx Decreasing+5V (-%Threshold
VINx Decreasing, +V (-10%) Threshold
VINx Decre+3.3V (-5%) Threshd
VINx Decreasg, +3.3V (-10%) Threshold
VINDecreasing, +3.0V (-5%) Teshold
VDeeasing, +3.0V (-1Threshold
Nx Decreasing, +2V (-1) Treshold
VINx Decreasing, +1.8V (0%) Threshold
VINx Increasi, -5V +5%) Threshold
VINx Inng, -5V (+10%) Threshold
x Decreasing
0.
.5
5
-20
4.50
.25
3.00
2.85
2.70
2.55
2.13
1.53
4.63
4.38
3.08
2.93
2.78
2.63
2.19
1.58
4.75
4.50
3.15
3.00
2.85
2.70
2.25
1.62
VTH
Reset Threshold Voltage
V
-4.75 -4.63 -4.50
-4.50 -4.38 -4.25
VTH
Adjustable Threshold
1.20
1.23
60
1.26
V
ppm/ºC
%
Threshold Voltage
Temperature Coefficient
VHYS
tRD
Threshold Hysteresis
0.5
VINx = VTH to (VTH - 50mV),
All Inputs Except -5V, or
VINx = VTH to (VTH + 50mV), -5V Input Only
Reset Delay
20
µs
tRP
Reset Active Timeout Piod
120
200
280
ms
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
4 - 16
AS1923
Datasheet - Electrical Characteristics
Table 3. Electrical Characteristics (Continued)
Parameter 1
Symbol
Conditions
Min
Typ
Max
Units
VIN2 = 5V, ISINK = 2mA
VIN2 = 2.5V, ISINK = 1.2mA
VIN1 = VIN2 = 1V, ISINK = 50µA
0.4
0.4
0.4
VOL
Output Low Voltage
V
Output High Voltage,
Output High Source Current
VIN2 > 2.55V, ISOURCE = 6µA
0.8 x
VIN2
6
V
VOH
(Reset Not Asserted)
VIN2 ≥ 2.55V (Reset Not Asserted),
VOUT ≥ 0.8 x VIN2
5
Output High Source Current
6
10
µA
IOH
1. 100% production tested at TAMB = +25ºC. Limits over temperature guaranteed by design.
2. The device is powered from input IN2.
3. The RESETN output is guaranteed to be in the correct state for IN1 or IN2 down to 1V.
4. Monitored voltage at IN2 (+3.3V, +3.0V) is also the device power supply. Supply current split is 25µA for the resistor-dividr network (for
the monitored voltage) and 30µA for other circuits.
5. Adjustable pin only.
6. AS1923B only.
Note: All limits are guaranteed. The parameters with min and max vaare guaranteed with prduction tests or SQC (Statistical Quality
Control) methods.
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
5 - 16
AS1923
Datasheet - Typical Operating Characteristics
7 Typical Operating Characteristics
Tamb = +25ºC, unless otherwise noted
Figure 3. IN2 Input Current vs. IN2 Input Voltage
Figure 4. IN2 Input Current vs. Temperature
85
70
80
75
70
65
60
55
65
VIN2 = 3.3V
60
VIN2 = 3.0V
55
50
3
3.5
4
4.5
5
5.5
-20
0
20
4
6
80
IN2 Input Voltage (V)
Temperature(°)
Figure 5. Reset Delay vs. Reset Threshold Overdrive;
VIN2 = 3.0V, IN decreasingVIN2 = 3.0V, IN decreasing
Figure Rest Timeout Periode . Temerature;
80
60
40
20
0
225
220
25
20
205
200
195
0
200
400
600
800
10
-40
-15
10
35
60
85
Reset Threshold Overdrive (m
Temperature (°C)
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
6 - 16
AS1923
Datasheet - Typical Operating Characteristics
Figure 7. Normalized Threshold Error vs. Temperature;
VIN2 = 3.0V
0.1
VTH = 5.0V
0
VTH = 1.8V
-0.1
-0.2
-0.3
-0.4
-40 -20
0
20
40
60
80
Temperature(°C)
Figure 8. Reset Delay; VIN2 = 3.0V
Figur9. Ret Active Timeout Periode; V2 = 3.0V
5µs/Div
50ms/Div
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
7 - 16
AS1923
Datasheet - Detailed Description
8 Detailed Description
The AS1923 is a very small, low-power, quad-voltage microprocessor supervisory circuit designed to maintain system integrity in multi-supply
systems (see Figure 10). The device offers several factory-trimmed under-voltage threshold values that minimize or eliminate the need for exter-
nal components.
Preset voltage monitoring values of +5.0, +3.3, +3.0, +2.5, +1.8, and -5.0V (see Ordering Information on page 14) are available for a wide range
of applications such as telecommunications equipment, desktop and notebook computers, high-end printers, data storage equipment, and net-
working equipment applications.
The device is powered via the IN2 input (3.0 to 3.3V) and a reset is asserted if VIN1 or VIN2 is > 1V. For improved performance, the AS1923 was
also designed to ignore fast INx transients.
Figure 10. AS1923 - Block Diagram
4
+
IN1
–
IN1
3V
5V Pullup
5
+
–
IN2
3
RESETN
Timeo
20ms)
6
+
–
IN3
1
+
–
IN4
Bandgap
Reference
AS1923
Optional on AS1923B Only
The quad-voltagmonior/reset circuitry includes an accurate bandgap reference, four precision comparators, and a series of internal trimmed
resistor-dividr networks to set the factory-trimmed reset threshold values.
Thresistnetorks scale the specified INx reset voltages to match the internal bandgap reference/comparator voltage. User-adjustable
threhold options bypass the internal resistor networks and connect directly to one of the comparator inputs (an external resistor-divider network
is requed for threshold matching).
Each of the internal comparators has a typical hysteresis of 0.5% with respect to its reset threshold. This built-in hysteresis improves device
immunity to ambient noise without significantly reducing threshold accuracy when an input sits at its specified reset voltage.
Note: Threshold voltage options (fixed and adjustable) are designated by the single-letter code in the model number (see Ordering Informa-
tion on page 14).
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
8 - 16
AS1923
Datasheet - Application Information
9 Application Information
Reset Output
The AS1923 RESETN output is asserted low when any of the monitored INx voltages drop below its specified reset threshold (above for -5V
option) and remains asserted for the duration of the reset timeout period (120ms minimum) after all inputs have stabilized (Figure 11).
Figure 11. RESETN Output Timing Diagram
INx
VTHL
RESETN
tRD
tRP
90%
10%
The AS1923B output driver is driven by an internal 10µA current source pullup esistor. For most applications this no eed for an external
pullup resistor to interface with other logic supplies.
Note: An external pullup resistor must not be connected to the AS123B.
The AS1923A supports an external pullup resistor to any voltage from 0 5.5V if interfaced to non-tandard logic supply voltages (see Figure
12).
Figure 12. Interfacing to Various Logic Supply Voltages
+5V
VCC
100kΩ
3
RES
RESETN
CPU
AS1923A
GND
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
9 - 16
AS1923
Datasheet - Application Information
User-Adjustable Thresholds
The AS1923 provides several voltage monitoring values as well as user-adjustable reset thresholds.
The threshold voltage at each adjustable INx input is typically 1.23V. To monitor a voltage >1.23V, connect a resistor-divider network to the circuit
as shown in Figure 13.
Figure 13. Setting User-Adjustable Thresholds
VINTH
R1
+
R2
–
+
VREF =
1.23V
–
For the circuit shown in Figure 13, calculate R1 and R2 as:
+ R2
------------------
VINTH = 1,2
(EQ 1)
(EQ 2)
R2
or, calculated in terms of R1:
VINTH
1,23V
⎛
⎞
R1 = R2 × --------------- 1
⎝
⎠
Note: Because the AS1923 has a guaranteput current of ±0.1µA on iadjustable inputs, resistor values up to 100kΩ can be used for
R2 with <1% error.
Unused Inputs
The IN2 input must always be used for normal operion (AS1923 power-supply pin). Otherwise, in cases where one or more of the AS1923
monitoring inputs will not be used, these inputs must be tied to a supply voltage greater in magnitude than their specified threshold voltages.
Notes:
1. For unused IN3 or IN4 applicatis with positive thresholds (fixed or adjustable), the inputs can be connected directly to the IN2 supply.
2. For unused IN4 options with egative thresholds, the input must be tied to a more negative supply.
3. Unused pins must not be onneted to ground or allowed to float.
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
10 - 16
AS1923
Datasheet - Application Information
Negative Voltage Monitoring Beyond -5V
The AS1923 is available with options to monitor -5V supplies using internally trimmed thresholds. In cases where monitored supplies are more
negative than -5V, an external low-impedance resistor-divider network can be used as shown in Figure 14.
The current through the external resistor-divider should be greater than the input current for the -5V monitor options. For an input monitor current
error of <1%, the resistor-divider current should be ≥ 2mA (for IIN4 = 20µA max).
Figure 14. Negative Voltage Monitoring Beyond -5V
R2
-5V
–
+
R1
+
–
VREF =
1.23V
VINTH
For the circuit shown in Figure 14, calculate R1 based on the desired VINx resehreshld voltage:
H
23V
⎞
R1 = R2 × ----- – 1
(EQ 3)
⎠
Where:
R2 ≤ 2.49kΩ
VINTH is the desired threshold voltage.
VTH is the internal threshold voltage.
For -VIN = -12V nominal:
VINTH = -11.1V,
VTH = -4.63V,
R2 = 2.49kΩ.
Using the equation given in (EQ 3), R1 can be calculated as:
–11,1V
–4,63V
⎛
⎞
1 = 2,49kΩ × ------------------ – 1
⎝
⎠
Therefore, R1 = 3.48kΩ
Power-Supply Bypassing and Grounding
The AS1923 is powered from the I2 suply input. All monitor inputs are immune to fast supply transients.
If higher immunity is required in oisy systems, connect 0.1µF bypass capacitors from the IN2 input to ground (see Figure 15). Additional capac-
itance can be added o IN1, N3, and IN4 to improve noise immunity at these inputs.
Figure 15. IN2 Aditional oise Immunity
5
3.0 to
3.3V
IN2
0.1µF
AS1923
2
GND
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
11 - 16
AS1923
Datasheet - Package Drawings and Markings
10 Package Drawings and Markings
Figure 16. 6-pin SOT23 Marking
Top Marking
Bottom Marking
xxxx- encoded Datacode
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
12 - 16
AS1923
Datasheet - Package Drawings and Markings
Figure 17. 6-pin SOT23 Package
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
13 - 16
AS1923
Datasheet - Ordering Information
11 Ordering Information
The device is available as the standard products listed in Table 4.
Table 4. Ordering Information
Ordering Code
Marking
Descriptiom
Delivery Form
Package
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
AS1923A-BSTT-A
Tape and Reel
6-pin SOT23
ASJD
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
AS1923A-BSTT-C
AS1923A-BSTT-I
AS1923A-BSTT-K
AS1923A-BSTT-O
AS1923A-BSTT-x*
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Ree
6-pin SOT23
6-pin SOT23
6-pin SO23
6-pin SOT23
6-pin SOT23
6-pin SOT23
ASJF
ASJP
ASJR
ASJV
tbd
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
Quad-Voltage Microprocessor Supervisory Circuit
with Open Drain Output
Quad-Voltage Microprocessor SupervisorCircuit
with Internal 10µA Current SourcPullup Otput
AS1923B-BSTT-x*
*) on request
tbd
Note: All products are RoHS compliant.
Buy our products or get free samples online at ICdiect: http://www.austriamicrosystes.com/ICdirect
For further information and requests, please ontat us mailto:sales@ustriarosstems.com
or find your local distributor at http://www.ustamicrosystems.com/distribtor
These devices are available in factory-set input voltage thresholds. Cthe desired reset threshold suffix from Table 5 and insert it instead of
“x” in the part number.
Table 5. Variants Suffix Guide (x)
Thresholds
Variant (x)
Tolerance
IN1
IN2
3
IN4
A
5.0V
3.3V
5V
adjustable
10%
5%
B 1
C
2.5V 2
1.8V
5.0V
5.0V
5.0V
3.3V
3.3
3.3V
adjustable
adjustable
adjustable
10%
5%
D 1
E 1
F 1
G 1
H 1
1.8V 2
0V
5.0V
5.0V
5.0V
3.0V
3.0V
3.0V
3.0V
2.5V
adjustable
adjustable
adjustable
adjustable
10%
5%
2.5V 2
1.8V
10%
5%
1.8V 2
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
14 - 16
AS1923
Datasheet - Ordering Information
Table 5. Variants Suffix Guide (x)
Thresholds
Variant (x)
IN1
Tolerance
IN2
IN3
IN4
2.5V 2
I
5.0V
3.3V
1.8V
10%
2.5V 2
2.5V
1.8V 2
J
5.0V
3.3V
3.3V
3.3V
5%
10%
5%
K
adjustable
adjustable
adjustable
L 1
2.5V 2
adjustable
-5.0V
M 1
5.0V
5.0V
3.0V
3.0V
adjustable
10%
5%
N 1
O
adjustable
-5.0V
5.0V
5.0V
3.3V
3.3V
adjustable
adjustable
-5.0V
-5.0V
10%
5%
P
1. Available upon request
2. Specified for 10% tolerances
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
15 - 16
AS1923
Datasheet
Copyrights
Copyright © 1997-2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®.
All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of
the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale.
austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding
the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and pries
any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG fo
current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature rae,
unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment ar
specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100
parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamirosysms AG shall not
be liable to recipient or any third party for any damages, including but not limiteto personal injury, property dam, loss f profits, loss of use,
interruption of business or indirect, special, incidental or consequential damags, of any nd, in connection with or ariing out of the furnishing,
performance or use of the technical data herein. No obligation or liability to recipnt or any third party shall rie oflow out of
austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters
austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaten, Astria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 313525 1
FSales Oices, Distributors and Representatives, please visit:
http://ww.austriamicrosystems.com/contact
www.austriamicrosystems.com/Supervisors/AS1923
Revision 1.01
16 - 16
相关型号：
©2020 ICPDF网 联系我们和版权申明