Data Sheet
PT7M7803/09/10
µP Supervisor Circuits
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Features
Precision supply-voltage monitor
-
-
-
-
-
-
4.63V (PT7M7803/09/10L)
4.26V (PT7M7803/09/10M)
3.08V (PT7M78003/09/10T)
2.93V (PT7M78003/09/10S)
2.63V (PT7M7803/09/10R)
2.32V (PT7M7803/09/10Z)
Description
The PT7M7803/09/10 are microprocessor (µP)
supervisory circuits used to monitor the power supplies
in µP and digital systems. They provide excellent circuit
reliability and low cost by eliminating external
components and adjustments when used with +3.3V,
+3.0V, or 2.5V powered circuits.
These circuits perform a single function: they assert
a reset signal whenever the VCC supply voltage declines
Configurations
for
below a preset threshold, keeping it asserted for at least
140ms after VCC has risen above the reset threshold.
RESET
Output
Configurations
for
Reset thresholds suitable for operation with a variety of
supply voltages are available.
/RESET
output
configuration
for
The PT7M7803 has an open-drain output stage,
while the PT7M7809/10 have push-pull outputs. The
PT7M7803’s open-drain /Reset output requires a pull-up
resistor that can be connected to a voltage higher than
V
CC
. The PT7M7803/09 have an active-low /RESET
output while the PT7M7810 has an active-high RESET
output. The reset comparator is designed to ignore fast
Package
Lead free and Green SOT23-3
Lead free and Green SOT23-3
Lead free and Green SOT23-3
transients on V
CC
, and the outputs are guaranteed to be
in the correct logic state for V
CC
down to 1V.
Low supply current makes the PT7M7803/09/10
ideal for use in portable equipment. The ICs are
available in 3 pin SOT23 packages.
140ms(min) reset pulse width
Push-Pull
PT7M7809
Push-Pull
PT7M7810
Open-Drain
PT7M7803
12µA Supply Current
Guaranteed Reset(/Reset) Valid to V
CC
= +1.0V
Power Supply Transient Immunity
No External Components
/RESET
Output
Ordering Information
Part Number
PT7M7803XTE
PT7M7809XTE
PT7M7809XTE
Note:
“x” refers to voltage range, see below table.
Suffix: X—Monitored Voltage
X
L
Reset Threshold (V)
4.63
M
4.26
T
3.08
S
2.93
R
2.63
Z
2.32
Block Diagram
V
CC
V
RST
+
-
Reset Logic
and Timer
RESET
PT0249(08/09)
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Ver: 8
Data Sheet
PT7M7803/09/10
µP Supervisor Circuits
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Pin Configuration
PT7M7803/09/10XT
1
GND
VCC
3
2
RESET
SOT23-3
Pin Description
Pin
Type
Description
Supply Voltage.
Reset is asserted when V
CC
drops below the Reset Threshold Voltage (V
RST
). Reset
remains asserted until V
CC
rises above V
RST
and keep asserted for the duration of the Reset Timeout
Period (t
RS
) once V
CC
rises above V
RST
.
Ground
Active-Low Reset Output (Push-Pull).
It goes low when Vcc is below the reset threshold. It remains
low for about 200ms after Vcc rises above the reset threshold (V
RST
).
VCC
-
GND
-
RESET
O
Functional Description
Reset Output
A microprocessor (µP) reset input starts the
µP
in a known state. Whenever the
µP
is in an unknown state, it should be held in
reset. The supervisory circuits assert reset during power-up and prevent code execution errors during power-down or brownout
conditions.
On power-up, once Vcc reaches about 1.0V, /RESET is a guaranteed logic low of 0.4V or less. As Vcc rises, /RESET stays low.
When Vcc rises above the reset threshold, an internal timer releases /RESET after about 200ms. /RESET pulses low whenever
Vcc drops below the reset threshold, i.e. brownout condition. If brownout occurs in the middle of a previously initiated reset pulse,
the pulse continues for at least another 200ms. On power-down, once Vcc falls below the reset threshold, /RESET stays low and is
guaranteed to be 0.4V or less until Vcc drops below 1.0V. Reset
Timing Diagram
shows the timing relationship.
PT0249(08/09)
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Data Sheet
PT7M7803/09/10
µP Supervisor Circuits
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Typical Application Circuit
PT0249(08/09)
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Data Sheet
PT7M7803/09/10
µP Supervisor Circuits
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Maximum Ratings
Storage Temperature ............................................................-65
o
C to +150
o
C
Ambient Temperature with Power Applied.......................... -40
o
C to +85
o
C
Supply Voltage to Ground Potential (Vcc to GND) ..............-0.3V to +6.0V
DC Input Voltage (All inputs except Vcc and GND)......-0.3V to V
CC
+0.3V
DC Output Current (All outputs) ..........................................................20mA
Power Dissipation .............................................................................. 320mW
Note:
Stresses greater than those listed under MAXIMUM
RATINGS may cause permanent damage to the
device. This is a stress rating only and functional
operation of the device at these or any other condi-
tions above those indicated in the operational sec-
tions of this specification is not implied. Exposure
to absolute maximum rating conditions for extended
periods may affect reliability.
Recommended Operation Conditions
Sym
V
CC
T
A
Description
Supply Voltage for 7803/09/10(L/M)
Supply Voltage for 7803/09/10(T/S)
Supply Voltage for 7803/09/10(R/Z)
Operating Temperature
Test Conditions
-
-
-
-
Min
4.5
3.0
2.7
-40
Typ
5.0
3.3
3.0
-
Max
5.5
5.5
5.5
85
Unit
V
V
V
℃
PT0249(08/09)
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Data Sheet
PT7M7803/09/10
µP Supervisor Circuits
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DC Electrical Characteristics
(V
CC
= V
RN
+ 5% to 5.5V, T
A
= -40~85ºC, unless otherwise noted.)(Note 1)
Symbol
V
CC
I
CC
I
CC
Description
Operating Voltage Range
Supply Current
Supply Current
Test Conditions
-
Vcc < 5.5V, PT7M78xxL/M
Vcc < 3.6V, PT7M78xxR/S/T/Z
T
A
= 25ºC
V
RST
（V
RTH
－
)
Threshold Voltage(Falling-
edge)(Note
2)
T
A
= -40 ~ 85ºC
T
A
= -40 ~ 85ºC
Threshold Voltage(Rising-
edge) (Note
2)
Reset Threshold Hysteresis
(Note
2)
PT7M7809M
All except
7809M
PT7M7809M
All except
7809M
PT7M7809M
Min
1.0
-
-
V
RN
-1.1%
V
RN
- 1.5%
V
RN
- 1.8%
V
RN
- 2.5%
Typ
-
10
10
V
RN
V
RN
V
RN
V
RN
Max
5.5
30
30
V
RN
+1.1%
V
RN
+ 1.5%
V
RN
+ 2%
V
RN
+ 2.5%
V
Unit
V
µA
V
RTH
＋
V
RTH
T
A
= -40 ~ 85ºC
4.232
-
Vcc-1.5
0.8×Vcc
0.8×Vcc
0.8×Vcc
-
-
4.31
50
-
-
-
-
-
-
4.396
-
-
-
-
-
0.4
0.3
V
V
mV
Vcc varies between V
RN
± 5%
(Only for 78xxL/M)
Vcc
≥
4.5V Isource=800µA
Vcc
≥
2.7V Isource=500µA
Vcc
≥
1.8V Isource=150µA
Vcc
≥
1.0V Isource=4µA
Vcc
≥
4.5V Isink=3.2mA
V
OH
Output High Voltage
V
OL
Output Low Voltage
Vcc
≥
2.7V Isink=1.2mA
-
-
0.3
Vcc
≥
1.0V Isink=100µA
Note: 1.
Parameters of room temperature guaranteed by production test and parameters of full-temperature guaranteed by design.
2.
V
RST
is Reset threshold voltage when V
CC
falls from high to low level. V
RN
is nominal reset threshold voltage.
AC Electrical Characteristics
Symbol
t
RS
Description
Reset Pulse Width
-
T
A
= 25ºC
Test Conditions
78xxT/S/R/Z
78xxL/M
Min
140
140
Typ
240
200
Max
560
280
Unit
ms
Reset Timing Diagram
VCC
V
RST
V
RST
+ V
RTH
t
RS
RESET
PT0249(08/09)
5
Ver: 8
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