TC51 Series
1
µ
A VOLTAGE DETECTOR WITH OUTPUT DELAY
FEATURES
s
s
s
s
s
s
s
Precise Detection Thresholds ....................
±
2.0%
Small Package ................................. 3-Pin SOT-23A
Low Supply Current .................................. Typ. 1
µ
A
Wide Detection Range .......................... 1.6V to 6.0V
Wide Operating Voltage Range ............ 0.7V to 10V
Built-in Delay Circuit ............. 50msec to 200 msec
Open-Drain Output
GENERAL DESCRIPTION
The TC51 is a very low power, open drain output, CMOS
voltage detector with built-in delay. It is particularly well-
suited for battery powered applications because of its ex-
tremely low 1
µA
operating current and small surface-mount
packaging. Each part is laser-trimmed to the desired thresh-
old voltage, which can be specified from 1.6V to 6.0V in 0.1V
steps. The standard built-in output delay is 50 msec – 200
msec.
The device includes a comparator, low-current high-
precision reference, laser-programmed voltage divider, hys-
teresis circuit, and output driver with digital delay timer.
In operation, the TC51’s output (V
OUT
) remains in the
logic HIGH state as long as V
IN
is greater than the
–
specified threshold voltage (V
DET
). When V
IN
falls below
–
V
DET
, the output is immediately driven to a logic LOW.
–
V
OUT
remains LOW until V
IN
rises above V
DET
by an
amount V
HYST
, whereupon it returns to a logic HIGH after
expiration of the built-in delay time.
APPLICATIONS
s
s
s
Battery Voltage Monitoring
Microprocessor Reset
System Brownout Protection
PIN CONFIGURATIONS
3-Pin SOT-23A**
V
IN
3
ORDERING INFORMATION
TC
51
1
2
PART CODE
TC51
N 18 0 2 E CB XX
Output Configuration:
N = Open Drain
Detected Voltage*:
Ex: 18 = 1.8V
Output Delay:
0 = 50msec – 200msec (standard)
Tolerance:
2 =
±2%
Temperature:
E: – 40°C to + 85°C
V
OUT
V
SS
** 3-Pin SOT-23A is equivalent to EIAJ SC-59.
FUNCTIONAL BLOCK DIAGRAM
V
IN
V
OUT
Package Type and Pin Count:
CB: 3-Pin SOT-23A**
Taping Direction:
TR: Standard Taping
RT: Reverse Taping
*Other voltages are available. Please contact Microchip
Technology Inc. for details.
Delay
Circuit
V
REF
V
SS
© 2001 Microchip Technology Inc.
DS21429A
TC51-1
7/22/99
1
µ
A VOLTAGE DETECTOR
WITH OUTPUT DELAY
TC51 Series
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage V
IN
......................................................12V
Output Voltage: Open-Drain ................. (V
SS
– 0.3) to 12V
Output Current ........................................................50 mA
Power Dissipation: (T
A
≤
70°C)
3-Pin SOT-23A .............................................. 240 mW
Operating Temperature .......................... – 40°C to + 85°C
Storage Temperature ........................... – 65°C to + 150°C
Soldering Temperature (10 sec) ............................. 300°C
*Static-sensitive device. Unused devices must be stored in conductive
material. Protect devices from static discharge and static fields. Stresses
above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. These are stress ratings only and functional
operation of the device at these or any other conditions above those
indicated in the operational sections of the specifications is not implied.
Exposure to Absolute Maximum Rating Conditions for extended periods
may affect device reliability.
ELECTRICAL CHARACTERISTICS:
T
A
= 25°C, unless otherwise specified.
Symbol
V
IN
I
SS
Parameter
Operating Voltage
Quiescent Current
Test Conditions
–
V
DET
= 1.6 to 6.0V
V
IN
= 1.5V
2.0V
3.0V
4.0V
5.0V
Note 1
Min
0.7
—
—
—
—
—
(V
T
)
x 0.98
–
(V
DET
)
x 0.02
—
—
Typ
—
0.9
1.0
1.3
1.6
2.0
V
T
±
0.5%
–
(V
DET
)
x 0.05
2.2
7.7
10.1
11.5
13.0
—
±
100
Max
10.0
2.6
3.0
3.4
3.8
4.2
(V
T
)
x 1.02
–
(V
DET
)
x 0.08
—
—
Unit
V
µA
–
V
DET
Threshold Voltage
Hysteresis Voltage
Output Current
V
V
mA
V
HYST
I
OUT
V
OL
= 0.5V
V
IN
= 1.0V
2.0V
3.0V
4.0V
5.0V
T
DLY
–
T
C
(V
DET
)
Delay Time
–
Tempco of (V
DET
)
Standard
– 40°C
≤
T
A
≤
85°C
50
—
200
—
msec
ppm/°C
NOTE
: 1. V
T
is the factory programmed threshold voltage setting.
PIN DESCRIPTION
3-Pin SOT-23A
Pin No.
1
2
3
Symbol
V
OUT
V
SS
V
IN
Description
Digital Output. This output goes low when V
IN
drops below V
DET
and returns high
when V
IN
rises above V
DET
+ V
HYST
. (See timing chart.)
Ground Terminal.
Analog Input. This pin is both the power supply input and the voltage to be monitored.
TC51-1 7/22/99
2
© 2001 Microchip Technology Inc.
DS21429A
1
µ
A VOLTAGE DETECTOR
WITH OUTPUT DELAY
TC51 Series
VIN
+
VDET
VHYST
RELEASE
VOLTAGE
–
DETECT VOLTAGE VDET
MINIMUM OPERATING
VOLTAGE
GROUND LEVEL
V
OUT
OUTPUT VOLTAGE
V
OUT
, stays valid until the input voltage falls below the
Minimum Operating Voltage, V
IN(MIN)
, of 0.7V. Below this
minimum operating voltage, the output is undefined. During
power-up or anytime V
IN
has fallen below V
IN(MIN)
, V
OUT
will
remain undefined until V
IN
rises above V
IN(MIN)
, at which time
the output will become valid. V
OUT
will be in its active low
+
–
state while V
IN(MIN)
< V
IN
< V
+
. (V
DET
= V
DET
+ V
HYST
). If
DET
+
and when the input rises above V
DET
, the output will assume
its inactive state after Delay Time (T
DLY
).
DELAY TIME (T
DLY
)
APPLICATIONS
GROUND LEVEL
Figure 1. Timing Chart
DETAILED DESCRIPTION
Please refer to Figure 1. In normal steady-state opera-
–
tion, when V
IN
> V
DET
, the output is high. If and when the
–
input falls below V
DET
, the output pulls down (Logic 0) to V
SS
.
Generally, V
OUT
can pull down to within 0.5V of V
SS
at
rated output current and input voltage, (See the
Electrical
Characteristics
section).
V
DD
V
DD
V
OUT
R1
47K
PROCESSOR
Processor RESET Supervisor
Figure 2 shows the TC51 used as a processor reset
supervisor. Because the TC51 is available in threshold
settings of 1.6V to 6.0V in 100mV steps, the user can choose
the reset single threshold setting best suited to the system
power supply voltage at hand (please see
Application
Note #36
). Also, the 1µA supply current is significantly lower
than its nearest competitor.
As shown in the timing diagram (Figure 1),V
OUT
is
+
guaranteed low for voltages between 0.7V and V
DET
.The
TC51 activates its on-board delay timer once the power
+
supply voltage is within tolerance (i.e. greater than V
DET
).
V
OUT
is released after delay time (T
DLY
).
Should the power supply voltage momentarily dip
(“brown-out” condition), the TC51 immediately drives and
holds the processor RESET input low. RESET is released
after the power supply voltage is again within tolerance, and
after the delay timer expires. RESET is driven and held low
when power fails (power-off or “blackout”), and is main-
tained low to a guaranteed supply voltage down to 0.7V.
RESET
TC51
GND
Figure 2. Processor Reset Supervisor
POWER-
UP
BROWN
OUT
STEADY
STATE
OPERATION
POWER DOWN
NOMINAL
POWER
SUPPLY VOLTAGE
THRESHOLD
VOLTAGE
(V
—DET
, V
+DFT
)
0.7V
TIME
V
OH
TC51 OUTPUT
V
OL
T
DLY
T
DLY
Figure 3. TC51 Operation During Power-Up, Brown-Out and Power Down.
© 2001 Microchip Technology Inc.
DS21429A
3
TC51-1
7/22/99
1
µ
A VOLTAGE DETECTOR
WITH OUTPUT DELAY
TC51 Series
TYPICAL CHARACTERISTICS
1. SUPPLY CURRENT VS. INPUT VOLTAGE
TC51N1602
4.0
SUPPLY CURRENT ISS (µA)
SUPPLY CURRENT ISS (µA)
TC51N2502
4.0
SUPPLY CURRENT ISS (µA)
TC51N3502
4.0
3.0
3.0
3.0
2.0
–30°C
T
A
= 80°C
1.0
25°C
2.0
T
A
= 80°C
1.0
25°C
0.0
–30°C
2.0
T
A
= 80°C
–30°C
1.0
25°C
0.0
0.0
0
2
4
6
8
10
INPUT VOLTAGE (V
IN
) (V)
0
2
8
4
6
INPUT VOLTAGE (V
IN
)
10
0
2
8
4
6
INPUT VOLTAGE (V
IN
)
10
2. THRESHOLD VOLTAGE, HYSTERESIS VOLTAGE VS. AMBIENT TEMPERATURE
TC51N1602
THRESHOLD HYSTERESIS VOLTAGE V–
DET
,V
HYST
THRESHOLD HYSTERESIS VOLTAGE V–
DET
,V
HYST
TC51N2502
THRESHOLD HYSTERESIS VOLTAGE V–
DET
,V
HYST
TC51N3502
3.8
3.7
3.6
V–
DET
3.5
3.4
3.3
3.2
–40
1.8
2.8
2.7
V
HYST
2.6
V–
DET
2.5
1.7
V
HYST
V–
DET
V
HYST
1.6
1.5
2.4
1.4
–40
–20
0
20
60 80
40
AMBIENT TEMPERATURE T
A
(°C)
2.3
–40
–20
0
20
60
40
80
AMBIENT TEMPERATURE T
A
(°C)
–20
0
20
60
40
80
AMBIENT TEMPERATURE T
A
(°C)
3. OUTPUT VOLTAGE VS. INPUT VOLTAGE
TC51N1602
3.0
OUTPUT VOLTAGE V
OUT
(V)
TC51N2502
4
OUTPUT VOLTAGE V
OUT
(V)
TC51N3502
5
OUTPUT VOLTAGE V
OUT
(V)
V
IN
– V
OUT: 100kΩ
T
A = 30°C
= 25°C
= 80°C
V
IN
– V
OUT: 100kΩ
T
A = 30°C
= 25°C
= 80°C
V
IN
– V
OUT: 100kΩ
T
A = 30°C
= 25°C
= 80°C
2.5
2.0
1.5
1.0
0.5
0.0
0
4
3
2
3
2
1
1
0
2
INPUT VOLTAGE V
IN
(V)
1
3
0
1
2
3
4
INPUT VOLTAGE V
IN
(V)
0
0
1
2
3
4
5
INPUT VOLTAGE V
IN
(V)
© 2001 Microchip Technology Inc.
DS21429A
TC51-1 7/22/99
4
1
µ
A VOLTAGE DETECTOR
WITH OUTPUT DELAY
TC51 Series
TYPICAL CHARACTERISTICS (CONT.)
4. OUTPUT CURRENT VS. V
DS
TC51N1602
15.0
OUTPUT CURRENT I
OUT
(mA)
TC51N1602
1400
OUTPUT CURRENT I
OUT
(µA)
T
A
= 25°C
T
A
= 25°C
12.5
10.0
7.5
5.0
1.0V
2.5
0.0
0.0
V
IN
= 1.5V
1200
1000
800
600
400
200
V
IN
= 0.8V
0.7V
0.5
1.0
V
DS
(V)
TC51N2502
1.5
2.0
0
0.2
0.4
0.6
0.8
1.0
V
DS
(V)
TC51N2502
1200
OUTPUT CURRENT I
OUT
(µA)
30
OUTPUT CURRENT I
OUT
(mA)
T
A
= 25°C
V
IN
= 2.0V
T
A
= 25°C
V
IN
= 0.8V
25
20
15
1000
800
600
400
200
0
0.0
0.7V
1.5V
10
5
0
0.0
0.5
1.0
1.5
2.0
2.5
0.2
0.4
0.6
0.8
1.0
V
DS
(V)
TC51N3502
60
OUTPUT CURRENT I
OUT
(mA)
V
DS
(V)
TC51N3502
1400
OUTPUT CURRENT I
OUT
(µA)
T
A
= 25°C
50
40
30
2.0V
20
1.5V
10
0
0
0.5
1.0
1.5
2.0
V
IN
= 3.0V
T
A
= 25°C
V
IN
= 0.8V
1200
1000
800
0.7V
600
400
200
0.0
2.5V
2.5
3.0 3.5
0.2
V
DS
(V)
© 2001 Microchip Technology Inc.
DS21429A
0.4
0.6
V
DS
(V)
0.8
1.0
5
TC51-1
7/22/99
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