®
SP809 / SP810
3 Pin Microprocessor Supervisor Circuit
FEATURES
■
Ultra Low Supply Current 1µA (typ.)
■
Guaranteed Reset valid to V
CC
= 0.9V
■
140 ms Min. Power-On Reset Pulse Width
■
Internally Fixed Threshold 2.3V, 2.6V, 2.9V,
3.1V, 4.0V, 4.4V, 4.6V
■
Tight Voltage Threshold Tolerance: 1.5%
■
Offered in a 3 Pin SOT-23 Package
Part Number
SP809N
SP809
SP810
Output Type
Open-Drain Active Low
Push-Pull Active Low
Push-Pull Active High
V
CC
SP809
3 Pin SOT-23
GND
RESET
Now Available in Lead Free Packaging
APPLICATIONS
■
Portable Electronic Devices
■
Electrical Power Meter
■
Digital Still Camera
■
µP
Power Monitoring
DESCRIPTION
The SP809/SP810 are low power microprocessor (µP) supervisory circuits used to monitor
power supplies in
µP
and digital systems. They provide applications with benefits of circuit
reliability and low cost by eliminating external components. If the V
CC
supply voltage falls below
preset threshold then a reset signal is asserted for at least 140ms after V
CC
has risen above the
reset threshold. Both the SP809 and SP810 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 (1µA) makes SP809/SP810 ideal for portable equipment. The devices are available in
3 pin SOT-23 package.
TYPICAL APPLICATION CIRCUIT
VCC
VCC
VCC
µP
RESET
(RESET)
GND
Push-Pull output
RESET
GND
Date: 11/9/04
SP809/810, 3 Pin Microprocessor Supervisor Circuit
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
V
CC
.................................................................................... -0.3V to 6.5V
RESET, RESET ......................................................... -0.3 to V
CC
+ 0.3V
Input Current (V
CC
) ....................................................................... 20mA
Output Current (RESET, RESET).................................................. 20mA
Continuous Power Dissipation (T
A
= +70ºC) ............................. 320mW
Operating Junction Temperature ................................... -40°C to +85°C
Junction Temperature.....................................................................125°C
Storage Temperature .................................................. -65°C to +150°C
Lead Temperature (soldering 10 sec)............................................125°C
These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation sections
of the specifications below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect reliability.
ELECTRICAL CHARACTERISTICS
Typical values are at T
A
= 25°C,
unless otherwise specified. (Note 1)
Parameter
Operating Voltage Range
Supply Current
Symbol
V
CC
I
CC
Min.
0.9
Typ.
Max.
6.0
Units
V
µA
Conditions
1.0
2.265
2.254
2.561
2.548
2.857
2.842
3.054
3.1
2.9
2.6
2.3
3.0
2.335
V
CC
= V
TH
+ 0.1V
T
A
= +25ºC
SP809-23
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
SP809-26
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
SP809-29
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
2.346
2.639
2.652
2.944
2.958
3.147
V
SP809-31
3.162
4.0
4.060
SP809-40
4.080
4.4
4.466
SP809-44
4.488
4.6
4.669
SP809-46
4.692
20
µS
560
ms
V
CC
= V
TH(MAX)
1030
Reset Threshold
V
TH
3.038
3.940
3.920
4.334
4.312
4.531
4.508
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
T
A
= -40ºC to + 85ºC
T
A
= +25ºC
T
A
= -40ºC to + 85ºC
V
CC
= V
TH
to (V
TH
- 0.1V), V
TH
= 3.1V
T
A
= +25ºC
T
A
= -40ºC to + 85ºC
V
CC
= V
TH
+ 0.1V, I
SOURCE
= 1mA
V
V
CC
Reset Delay
Reset Active Timeout
Period
V
TRIP
140
T
RP
100
V
OL
0.8V
CC
230
RESET Output Voltage
V
OH
V
OL
RESET Output Voltage
V
OH
Date: 11/9/04
0.2V
CC
0.8V
CC
V
0.2V
CC
V
CC
= V
TH
- 0.1V, I
SINK
= 1mA
V
CC
= V
TH
+ 0.1V, I
SOURCE
= 1mA
V
CC
= V
TH
- 0.1V, I
SINK
= 1mA
© Copyright 2004 Sipex Corporation
SP809/810, 3 Pin Microprocessor Supervisor Circuit
2
ELECTRICAL CHARACTERISTICS
Note 1. Specifications are production tested at T
A
= 25
°
C. Specifications over the -40
°
C to 85
°
C operating
temperature range are assured by design, characterization and correlation with Statistical Quality Controls
Note 2. RESET output is for SP809; RESET output is for SP810.
BLOCK DIAGRAMS
VCC
R1
Bandgap
Reset Generator
R2
GND
NMOS
Reset
N-ch Open-Drain Type
VCC
R1
Bandgap
Reset Generator
Reset
(Reset)
R2
GND
Push-Pull Type
TEST CIRCUIT
VCC
SP809
RESET
GND
Date: 11/9/04
SP809/810, 3 Pin Microprocessor Supervisor Circuit
© Copyright 2004 Sipex Corporation
3
TYPICAL PERFORMANCE CHARACTERISTICS
1.5
120
1.4
1.3
1.2
Power-Down Reset Delay (µS)
110
V
TH
= 2.3V
100
V
OD
= 50mV
90
80
70
60
50
40
30
V
TH
= 2.3V
V
OD
= V
TH
- V
CC
Supply Current (µA)
1.1
1.0
0.9
0.8
0.7
0.6
0.5
-40
V
TH
= 3.1V
V
TH
= 4.6V
V
OD
= 100mV
20
10
0
V
OD
= 200mV
-20
0
20
40
60
80
100
-60
-40
-20
0
20
40
60
80
100
Temperature (ºC)
Temperature (°C)
Figure 1. Supply Current vs. Temperature
240
220
200
Figure 2. Power-Down Reset Delay vs. Temperature
400
V
TH
= 3.1V
V
OD
= V
TH
- V
CC
V
OD
= 50mV
V
OD
= 50mV
300
Power-Down Reset Delay (µS)
V
TH
= 4.6V
V
OD
= V
TH
- V
CC
180
Power-Down Reset Delay (µS)
160
140
120
100
80
60
40
20
0
200
V
OD
= 100mV
V
OD
= 100mV
100
V
OD
= 200mV
V
OD
= 200mV
0
-60
-40
-20
0
20
40
60
80
100
-60
-40
-20
0
20
Temperature (ºC)
40
60
80
100
Temperature (°C)
Figure 3. Power-Down Reset Delay vs. Temperature
Figure 4. Power-Down Reset Delay vs. Temperature
600
1.015
V
TH
= 4.6V
1.010
500
V
TH
= 4.6V
Power-Up Reset Timeout (ms)
V
TH
= 3.1V
400
Normalized Reset Threshold (V)
V
TH
= 3.1V
1.005
V
TH
= 2.3V
1.000
V
TH
= 2.3V
300
0.995
200
0.990
100
0.985
-40
-20
0
20
40
60
80
100
0
Temperature (ºC)
-60
-40
-20
0
20
40
60
80
100
Temperature (°C)
Figure 5. Normalized Reset Threshold vs. Temperature
Date: 11/9/04
Figure 6. Power-Up Reset Time-out vs. Temperature
© Copyright 2004 Sipex Corporation
SP809/810, 3 Pin Microprocessor Supervisor Circuit
4
PIN DESCRIPTION
Pin Name
GND
RESET (SP809)
RESET (SP810)
V
CC
Ground.
Active low output pin. RESET Output remains low while VCC is below the reset
threshold.
Active high output pin. RESET Output remains high while VCC is below the reset
threshold.
Supply Voltage
Description
DETAILED DESCRIPTION
µP
will be activated at a valid reset state.
These
µP
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
>V
CC
>0.9V. Once V
CC
exceeded the reset
threshold, an internal timer keeps RESET low
for the reset timeout period; after this interval,
RESET goes high.
If a brownout condition occurs (V
CC
drops
below the reset threshold), RESET goes low.
Any time V
CC
goes below the reset threshold,
the internal timer resets to zero, and RESET
goes low. The internal timer is activated after
V
CC
returns above the reset threshold, and
RESET remains low for the reset timeout
period.
Negative-Going V
CC
Transients
In addition to issuing a reset to the
µP
during
power-up, power-down, and brownout condi-
tions, SP809 series are relatively resistant to
short-duration negative-going V
CC
transient.
Ensuring a Valid Reset Output Down to
VCC= 0
When V
CC
falls below 0.9V, SP809 RESET
output no longer sinks current; it becomes
an open circuit. In this case, high-imped-
ance CMOS logic inputs connecting to
RESET can drift to undetermined voltages.
Therefore, SP809/810 with CMOS is
perfect for most applications of V
CC
down to
0.9V.
Benefits of Highly Accurate Reset
Threshold
SP809/810 with specified voltage as 5V±10%
or 3V±10% are ideal for systems using a
5V±5% or 3V±5% power supply. The reset is
guaranteed to assert after the power supply
falls below the minimum specified operating
voltage range of the system ICs. The
pretrimmed thresholds are reducing the range
over which an undesirable reset may occur.
APPLICATION INFORMATION
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
µ
P with Bidirectional
Reset Pins
The RESET output on the SP809N is open
drain, this device interfaces easily with
µPs
that have bidirectional reset pins. Connect-
ing the
µP
supervisor's RESET output
directly to the microcontroller's RESET pin
with a single pull-up resistor allows either
device to assert reset.
Date: 11/9/04
SP809/810, 3 Pin Microprocessor Supervisor Circuit
© Copyright 2004 Sipex Corporation
5
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