Datasheet
AS1910 - AS1915
D u a l - Vo l t a g e M i c r o p r o c e s s o r S u p e r v i so r y C i r c u i t s w i t h M a n u a l R e s e t
a n d Wat c h d o g
1 General Description
The AS1910 - AS1915 microprocessor supervisory circuits were
designed to generate a reset when one of the two monitored supply
voltages falls below a factory-trimmed threshold, and to maintain the
reset for a minimum timeout period when both supplies are above
their reset thresholds. Guaranteed to be in the correct state for V
CC
higher than +1.0V, these devices are ideal for multiple-voltage
systems with strict monitoring requirements.
The AS1913/AS1914/AS1915 feature factory-trimmed thresholds to
monitor a primary voltage between 1.8 and 3.6V, and a secondary
voltage between 0.9 and 2.5V.
For the AS1910/AS1911/AS1912, a secondary monitoring voltage
can be user-adjusted via an external resistor divider down to 0.6V.
The devices are available with the reset output types listed in
Table
1.
Table 1. Standard Products
Model
AS1910/AS1913
AS1911/AS1914
AS1912/AS1915
Reset Output Type
Active-Low Push/Pull
Active-High Push/Pull
Active-Low Open-Drain
2 Key Features
Primary V
CC
Supervisory Range: +1.8 to +3.6V
Secondary V
CC
Supervisory Range: +0.9 to +2.5V (AS1913/
AS1914/AS1915)
User-Adjustable Threshold Down to +0.63V (AS1910/AS1911/
AS1912)
Guaranteed Reset Valid Down to V
CC
= +1.0V
Reset Timeout Delay: 215ms
Manual Reset Input
Three Reset Output Types:
- Active-High Push/Pull
- Active-Low Push/Pull
- Active-Low Open-Drain
Watchdog Timeout Period: 1.5s
Immune to Fast Negative V
CC
Transients
External Components Not Required
Operating Temperature Range: -40 to +125ºC
6-pin SOT23 Package
The AS1910 - AS1915 include a manual-reset input for systems that
never fully power down the microprocessor. Additionally, these
devices feature a watchdog timer to help ensure that the processor is
operating within proper code boundaries.
The AS1910 - AS1915 are available in a 6-pin SOT23 package.
Figure 1. Typical Application Diagram
3 Applications
The devices are ideal for portable and battery-powered systems,
embedded controllers, intelligent instruments, automotive systems,
critical CPU monitoring, and any multi-supply application.
V
CC
6
VCC
Core
Supply
I/O Supply
V
CC2
5
VCC2
3
AS1913/
AS1915
1
RESETN
4
WDI
I/O
RESETN
CPU
External
Reset
MRN
GND 2
GND
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AS1910 - AS1915
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
RESETN/RESET 1
6 VCC
GND 2
AS1910 -
AS1915
5 RESETIN/VCC2
MRN 3
4 WDI
4.1 Pin Descriptions
Table 2. Pin Descriptions
Pin Number
Pin Name
Description
Active-Low Reset Output
(AS1910, AS1912, AS1913, AS1915). The RESETN signal toggles from high to low
when V
CC
, V
CC2
, or RESETIN input drops below the factory-trimmed reset threshold
(see Table 4 on page 4),
or MRN is pulled low, or the watchdog triggers a reset. This output signal remains low for the reset timeout period
after all supervised voltages exceed their reset threshold, or MRN goes low to high, or the watchdog triggers a
reset.
Active-High Reset Output
(AS1911, AS1914). The RESET signal toggles from low to high when V
CC
, V
CC2
, or
RESETIN input drops below the factory-trimmed reset threshold
(see Table 4 on page 4),
or MRN is pulled low,
or the watchdog triggers a reset. This output signal remains high for the reset timeout period (see t
RP
on
page 5)
after all supervised voltages exceed their reset threshold, or MRN goes low to high, or the watchdog triggers a
reset.
Ground
Active-Low Manual Reset Input.
Pulling this pin low asserts a reset. This pin is connected to the internal 50kΩ
pullup to V
CC
. This reset remains active as long as MRN is low and for the reset timeout period (see t
RP
on
page 5)
after MRN goes high.
Note:
If the manual reset feature is not used, this pin should be unconnected or connected to V
CC
.
Watchdog Input.
If WDI remains high or low for longer than the watchdog timeout period (see t
WD
on
page 6),
the internal watchdog timer period expires and a reset is triggered for the reset timeout period (see t
RP
on
page
5).
The internal watchdog timer clears whenever a reset is a asserted or when WDI senses a rising or falling
edge.
Note:
To disable the watchdog feature, this pin must be unconnected or connected to a tri-state buffer output.
WDI must be low or unconnected (tristate) during the reset timeout period tRP,
(see Figure 13 on page 10).
User-Adjustable Supervised Voltage Input
(AS1910/AS1911/AS1912). This high-impedance pin serves as the
input to the internal reset comparator. Connect this pin to an external resistor-divider network to set the reset
threshold voltage (down to 0.63V).
Primary Supervised Voltage Input
(AS1913/AS1914/AS1915). This pin serves as the secondary supervised
voltage input.
Primary Supervised Voltage Input.
This pin serves as the primary supervised voltage input.
RESETN
1
RESET
2
GND
3
MRN
4
WDI
RESETIN
5
VCC2
6
VCC
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AS1910 - AS1915
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 3
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 3. Absolute Maximum Ratings
Parameter
Electrical Parameters
V
CC
, V
CC2
to GND
Open-Drain RESETN
Push/Pull RESET, RESETN
MRN, WDI, RESETIN to GND
Input Current (V
CC
)
Output Current (RESET, RESETN)
Continuous Power Dissipation
Continuous Power Dissipation
(T
AMB
= +70ºC)
Temperature Ranges and Storage Conditions
Junction Temperature
Storage Temperature Range
-55
+150
+150
ºC
ºC
The reflow peak soldering temperature (body temperature)
specified is in accordance with
IPC/JEDEC J-STD-020
“Moisture/Reflow Sensitivity Classification for Non-
Hermetic Solid State Surface Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin
(100% Sn).
Represents a max. floor life time of unlimited
696
mW
Derate 8.7mW/ºC above +70ºC
-0.3
-0.3
-0.3
-0.3
+5.0
+7.0
V
CC
+
0.3
V
CC
+
0.3
20
20
V
V
V
V
mA
mA
Min
Max
Units
Comments
Package Body Temperature
+260
ºC
Humidity non-condensing
Moisture Sensitive Level
8
1
85
%
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AS1910 - AS1915
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
CC
= +2.7 to +3.6V for AS19xx-T/S/R, V
CC
= +2.1 to +2.75V for AS19xx- Z/Y, V
CC
= +1.53 to +2.0V for AS19xx-W/V; Typical values @ T
AMB
= +25ºC
(unless otherwise specified).
Table 4. Electrical Characteristics
Symbol
T
AMB
V
CC
Parameter
1
Conditions
T
AMB
= 0 to +85ºC
T
AMB
= -40 to +125ºC
V
CC
= +3.6V, No Load,
T
AMB
= -40ºC to +85ºC
V
CC
= +3.6V, No Load,
T
AMB
= -40 to +125ºC
V
CC2
= +2.5V
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
AS19xx-T
AS19xx-S
AS19xx-R
AS19xx-Z
AS19xx-Y
AS19xx-W
AS19xx-V
AS19xx-Z
AS19xx-Y
AS19xx-W
AS19xx-V
AS19xx-I
AS19xx-H
AS19xx-G
AS19xx-F
AS19xx-E
AS19xx-D
Min
-40
1.0
1.2
Typ
Max
+125
3.6
3.6
Units
ºC
V
Operating Temperature Range
Operating Voltage Range
V
CC
Supply Current
(MRN and WDI Not Connected)
V
CC2
Supply Current
5.8
13
µA
21
2
µA
I
CC
I
CC2
2.994
2.972
2.848
2.827
2.556
2.538
2.255
2.239
2.129
2.113
1.623
1.612
1.536
1.525
2.237
2.232
2.116
2.111
1.610
1.607
1.523
1.520
1.342
1.339
1.270
1.267
1.073
1.071
1.015
1.013
0.806
0.804
0.762
0.760
3.08
2.93
2.63
2.32
2.19
1.67
1.58
2.313
2.188
1.665
1.575
1.388
1.313
1.11
1.05
0.833
0.788
3.154
3.179
3.000
3.024
2.693
2.714
2.376
2.394
2.243
2.260
1.710
1.723
1.618
1.631
2.387
2.394
2.258
2.265
1.718
1.723
1.625
1.630
1.432
1.437
1.355
1.359
1.146
1.149
1.084
1.087
0.860
0.862
0.813
0.816
V
V
V
TH
V
CC
Reset Threshold
(V
CC
Falling)
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
V
TH2
V
CC2
Reset Threshold
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Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 4. Electrical Characteristics
Symbol
Parameter
1
Conditions
Min
Typ
60
8 x V
TH
Max
Units
ppm/ºC
mV
Reset Threshold
Temperature Coefficient
Reset Threshold Hysteresis
V
RESETIN
TH
RESETIN Threshold
RESETIN Hysteresis
V
RESETINTH
Falling, T
AMB
= 0 to +85ºC
T
AMB
= -40 to +125ºC
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
V
CC
= V
TH
to (V
TH
- 100mV)
V
RESETIN
= V
RESETINTH
to
(V
RESETINTH
- 30mV)
T
AMB
= -40 to +85ºC
T
AMB
= -40 to +125ºC
V
CC
≥
1.0V, I
SINK
= 50µA,
Reset Asserted, T
AMB
= 0 to +85ºC
0.615
0.61
0.630
8 x V
TH
0.645
0.65
+25
+100
V
mV
nA
µs
µs
I
RESETIN
t
RD
RESETIN Input Current
V
CC
to Reset
Output Delay
RESETIN to Reset
Output Delay
2
-25
-100
55
45
140
100
215
t
RP
Reset Timeout Period
280
320
0.3
0.3
0.3
0.4
ms
V
OL
RESETN Output Low
(Push/Pull or Open-Drain)
V
CC
≥
1.2V, I
SINK
= 100µA, Reset Asserted
V
CC
≥
2.55V, I
SINK
= 1.2mA,
Reset Asserted
V
CC
≥
3.3V, I
SINK
= 3.2mA,
Reset Asserted
V
CC
≥
1.8V, I
SOURCE
= 200µA,
Reset Not Asserted
0.8 x
V
CC
0.8 x
V
CC
0.8 x
V
CC
V
V
OH
RESETN Output High
(Push/Pull Only)
V
CC
≥
3.15V, I
SOURCE
= 500µA,
Reset Not Asserted
V
CC
≥
3.3V, I
SOURCE
= 800µA,
Reset Not Asserted
V
I
LKG
Open-Drain RESETN Output Leakage
Current
RESETN Not Asserted
T
AMB
= +25ºC
V
CC
≥
1.0V, I
SOURCE
= 1µA,
Reset Asserted, T
AMB
= 0 to +85ºC
0.8 x
V
CC
0.8 x
V
CC
0.8 x
V
CC
0.8 x
V
CC
1.0
0.2
µA
V
OH
RESET Output High
(Push/Pull Only)
V
CC
≥
1.50V, I
SOURCE
= 100µA,
Reset Asserted
V
CC
≥
2.55V, I
SOURCE
= 500µA,
Reset Asserted
V
CC
≥
3.3V, I
SOURCE
= 800µA,
Reset Asserted
V
CC
≥
1.8V, I
SINK
= 500µA,
Reset Asserted
V
0.3
0.3
0.4
0.3 x
V
CC
0.7 x
V
CC
1
90
V
V
OL
RESET Output Low
(Push/Pull Only)
V
CC
≥
3.15V, I
SINK
= 1.2mA,
Reset Asserted
V
CC
≥
3.3V, I
SINK
= 3.2mA,
Reset Asserted
Manual Reset Input
V
IL
MRN Input voltage
V
IH
MRN Minimum Input Pulse
MRN Transient Rejection
V
µs
ns
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