®
SP730
Microprocessor Supervisory
Circuit with Pull Up Resistor
FEATURES
■
Holds Microcontroller in Reset
■
Reset Microcontroller during power loss
■
4.375 Voltage Trip Point
■
Active Low RESET Pin
■
Internal Pull-up Resistor
■
Holds RESET for 350ms (typical)
■
RESET valid down to V
DD
1.0V
■
45µA Typical Operating Current
■
Offered in a 3 Pin SOT-23 Package
APPLICATIONS
■
Portable Electronic Devices
■
Electrical Power Meter
■
Computer System Board
■
Modem
GND
SP730
3 Pin SOT-23
RESET
V
DD
Now Available in Lead Free Packaging
DESCRIPTION
The SP730 is a voltage supervisory device designed to keep a microcontroller in reset until the
system voltage has reached the proper level and stabilized. It also operates as protection from
brown-out conditions when the supply voltage drops below a safe operating level. The SP730
has an internal 5k pull-up resistor. The device has an active low RESET pin and will assert the
RESET signal whenever the voltage on the V
DD
pin is below the trip-point voltage. The part is
available in a small 3 pin SOT-23 package. Contact factory for other trip voltage options.
TYPICAL APPLICATION CIRCUIT
VDD
Microcontroller
SP730
VDD
GND
RESET
Bypass
Capacitor
VDD
MCLR
or
RESET
GND
Date: 6/14/04
SP730 Microprocessor Supervisory Circuit
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
V
DD
................................................................................................. 6.0V
All inputs and outputs w.r.t. GND ............................... -0.6 to V
DD
+ 1.0V
Storage Temperature .................................................. -65°C to +150°C
Ambient Temperature with power applied.....................-65°C to +125°C
ESD Protection on all pins ............................................................
≥2kV
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
V
DD
= 1.0V - 5.5V ; -40°C to 85°C.
The
♦
denotes the specifications which apply over the full operating temperature range, unless otherwise
specified.
Parameter
Operating Voltage Range
V
DD
Value to RESET
Operating Current
V
DD
Trip Point
Threshold Hysteresis
RESET Low Level Output
Voltage
RESET High Level Output
Voltage
Pull up Resistor
V
DD
Detect to RESET Inactive
Symbol
V
DD
V
DDMIN
I
DD
V
TRIP
V
HYS
V
OL
V
OH
Min.
1.0
1.0
Typ.
Max.
5.5
♦
♦
Units
V
V
µA
V
mV
V
V
K
ms
Conditions
45
4.25
4.375
50
60
4.50
♦
♦
♦
V
DD
= 5.5V (no load)
0.6
V
DD
-.7
5
♦
♦
♦
I
OL
= 8.5mA, V
DD
=
V
TRIP MIN
I
OH
= 50µA, V
DD
>
V
TRIP MAX
t
RPU
150
350
700
♦
V
DD
Detect to RESET
t
RPD
10
♦
µS
V
DD
ramped from
V
TRIP MAX
(V
TRIP MAX +
250mV) to (V
TRIP MIN -
250mV)
Date: 6/14/04
SP730 Microprocessor Supervisory Circuit
© Copyright 2004 Sipex Corporation
2
FUNCTIONAL DIAGRAM
V
DD
Comparator
Delay Circuit
Output Driver
RESET
Bandgap
Reference
5kΩ Internal pull
up resistor
TIMING DIAGRAM
V
TRIP
V
DD
tRPU
tRPD
V
OH
RESET
V
OH
Figure 1: SP730 Timing Diagram
PIN DESCRIPTION
PIN NUMBER
1
2
3
PIN NAME
RESET
V
DD
GND
3 PIN SOT-23 DESCRIPTION
Active Low. This pin goes low whenever V
DD
falls below the reset
threshold.
Supply input.
Ground.
Date: 6/14/04
SP730 Microprocessor Supervisory Circuit
© Copyright 2004 Sipex Corporation
3
TYPICAL PERFORMANCE CHARACTERISTICS
Idd vs Temperature
60
50
Operating Current (uA)
40
30
Idd
20
10
0
-40
-20
0
20
Temperature ('C)
40
60
80
100
tRPU vs Temperature
700
600
500
Timeout Period (mS)
400
tRPU
300
200
100
-40
-20
0
20
Temperature ('C)
40
60
80
100
Date: 6/14/04
SP730 Microprocessor Supervisory Circuit
© Copyright 2004 Sipex Corporation
4
TYPICAL PERFORMANCE CHARACTERISTICS
Normalized VTRIP vs Temperature
1.0020
1.0000
0.9980
Normalized Threshold
0.9960
0.9940
0.9920
0.9900
-40
-20
0
20
Temperature ('C)
40
60
80
100
VOL vs IOL
1200
1100
1000
900
800
700
VOL (mV)
600
500
400
300
200
Vdd=4.25V
Vdd=3.5V
Vdd=2.5V
Temp = 25'C
100
0
0
1
2
3.2
4
5
6
7
8.5
9
10
IOL (mA)
11
12
13
14
15
16
17
18
19
20
Date: 6/14/04
SP730 Microprocessor Supervisory Circuit
© Copyright 2004 Sipex Corporation
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