TC54
Voltage Detector
Features
• Precise Detection Thresholds: Standard ±2.0%,
Custom ±1.0%
• Small Packages: 3-Pin SOT-23A, 3-Pin SOT-89,
TO-92 and 5-Pin SOT-23A (7.7V only)
• Low Current Drain: Typ. 1 µA
• Wide Detection Range: 1.1V to 6.0V and 7.7V
• Wide Operating Voltage Range: 0.7V to 10V
General Description
The TC54 series are CMOS voltage detectors that are
especially well suited for battery-powered applications
because of their extremely low 1 µA operating current
and small surface-mount packaging. Each part is laser-
trimmed to the desired threshold voltage, which can be
specified from 1.4V to 7.7V for a 2% tolerance and from
1.5V to 6.0V for a 1% tolerance.
The device includes a comparator, low-current high-
precision reference, laser-trimmed divider, hysteresis
circuit and output driver. The TC54 is available with
either an open-drain or complementary output stage.
During operation, the TC54'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 driven to a logic-low. V
OUT
remains low until V
IN
rises above V
DET
– by an amount
V
HYST
, whereupon it resets to a logic-high.
TC54VC
only
Applications
•
•
•
•
•
Battery Voltage Monitoring
Microprocessor Reset
System Brown-Out Protection
Switching Circuit in Battery Backup
Level Discriminator
Functional Block Diagram
2
V
IN
V
OUT
1
Package Types
3-Pin SOT-23A
V
IN
3-Pin SOT-89
V
IN
–
+
3
TC54
TC54
1
2
V
SS
2
3
V
OUT
V
IN
V
SS
5-Pin SOT-23A
NC
NC
5
4
1
V
REF
V
SS
3
V
OUT
3-Pin TO-92
123
TC54VN
has open-drain output.
TC54VC
has complementary output.
TC54
1
V
OUT
V
IN
V
SS
Note:
2
3
V
OUT
V
IN
V
SS
3-Pin SOT-23A is equivalent to the
EIAJ SC-59
5-Pin SOT-23A is equivalent to the
EIAJ SC-74A. (7.7V ONLY)
2004 Microchip Technology Inc.
DS21434G-page 1
TC54
1.0
ELECTRICAL
CHARACTERISTICS
†
Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent 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
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.
Absolute Maximum Ratings †
Input Voltage ...................................................................+12V
Output Current ..............................................................50 mA
Output Voltage: CMOS................(V
SS
– 0.3V) to (V
IN
+ 0.3V)
Open-Drain.....................(V
SS
– 0.3V) to 12V
Power Dissipation (T
A
≤
70°C):
3-Pin SOT-23A .......................................................240 mW
3-Pin SOT-89..........................................................500 mW
5-Pin SOT-23A .......................................................240 mW
3-Pin TO-92 ............................................................300 mW
Operating Temperature Range........................-40°C to +85°C
Storage Temperature Range .........................-65°C to +150°C
PIN FUNCTION TABLE
Symbol
V
OUT
V
IN
V
SS
NC
NC
Description
Digital Output
Analog Input
Ground Terminal
No Connect
No Connect
DC CHARACTERISTICS
Electrical Specifications:
Unless otherwise noted, T
A
= +25°C.
Parameter
Operating Voltage
Quiescent Current
Sym
V
IN
I
SS
Min
0.7
—
—
—
—
Threshold Voltage
(Note 1)
V
DET
–
1.37
2.06
2.65
2.84
2.94
4.12
4.21
7.54
Hysteresis Voltage
V
HYST
28
42
54
58
60
84
86
154
Output Current
I
OUT
—
—
—
—
—
Tempco of (V
DET
–)
Delay Time
Note 1:
T
C
(V
DET
–)
t
DLY
—
—
Typ
—
0.8
0.9
1.0
1.1
1.4
2.1
2.7
2.9
3.0
4.2
4.3
7.7
70
105
135
145
150
210
215
385
7.7
10.1
11.5
13.0
-10.0
±100
—
Max
10.0
2.7
3.0
3.2
3.6
1.43
2.14
2.75
2.96
3.06
4.28
4.39
7.86
112
168
216
232
240
336
344
616
—
—
—
—
—
—
0.2
mA
mV
V
Units
V
µA
Test Conditions
(V
DET
–) = 0.8 to 6.0V
V
IN
= 2.0V
V
IN
= 3.0V
V
IN
= 4.0V
V
IN
= 5.0V
TC54VX14
TC54VX21
TC54VX27
TC54VX29
TC54VX30
TC54VX42
TC54VX43
TC54VX77 (5-pin SOT-23A only)
V
DET
= 1.4V (typ)
V
DET
= 2.1V (typ)
V
DET
= 2.7V (typ)
V
DET
= 2.9V (typ)
V
DET
= 3.0V (typ)
V
DET
= 4.2V (typ)
V
DET
= 4.3V (typ)
V
DET
= 7.7V (typ)
V
OL
= 0.5V, V
IN
= 2.1V
V
IN
= 3.0V
V
IN
= 4.0V
V
IN
= 5.0V
TC54VC Only:
V
OH
= V
IN
– 2.1V, V
IN
= 8.0V
ppm/°C -40°C
≤
T
A
≤
85°C
ms
V
DET
–
→
V
OUT
inversion
For other voltage options, please contact your regional Microchip sales office.
DS21434G-page 2
2004 Microchip Technology Inc.
TC54
V
DET
–
V
DD
t
DLY
V
OH
OUTPUT
FIGURE 1-1:
Timing Diagram.
2004 Microchip Technology Inc.
DS21434G-page 3
TC54
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
PIN FUNCTION TABLE
Pin No.
(3-Pin SOT-89)
(3-Pin TO-92)
1
2
3
—
—
Pin No.
(5-Pin SOT-23A)
1
2
3
4
5
Symbol
V
OUT
V
IN
V
SS
NC
NC
Digital Output
Analog Input
Ground Terminal
No Connect
No Connect
Description
Pin No.
(3-Pin SOT-23A)
1
3
2
—
—
2.1
Digital Output (V
OUT
)
2.3
Ground Terminal (V
SS
)
V
OUT
goes low when V
IN
drops below V
DET
– and
returns high when V
IN
rises above V
DET
– + V
HYST
.
(See Figure 3-1).
V
SS
provides the negative reference for the analog
input voltage. Typically, the circuit ground is used.
2.4
2.2
Analog Input (V
IN
)
V
IN
can be used for power supply monitoring or a
voltage level that requires monitoring.
No Connect (NC)
No internal connection.
DS21434G-page 4
2004 Microchip Technology Inc.
TC54
3.0
DETAILED DESCRIPTION
In normal steady-state operation when V
IN
> V
DET
–,
the output will be at a logic-high (see Figure 3-1). In
the case of the TC54VN, this is an open-drain
condition. If the input falls below V
DET
–, the output
will pull 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
Section 1.0 “Electrical
Characteristics”).
The output (V
OUT
) will stay valid until the input voltage
falls below the minimum operating voltage (V
INMIN
) of
0.7V. Below this minimum operating voltage the output
is undefined. During power-up (or anytime V
IN
has
fallen below V
INMIN
), V
OUT
will remain undefined until
V
IN
rises above V
INMIN
. Once this occurs, the output
will become valid. V
OUT
will be in its active-low state,
while V
INMIN
< V
IN
< V
DET
+ (therefore, V
DET
+ = V
DET
–
+ V
HYST
). If the input rises above V
DET
+, the output will
assume its inactive state (high for TC54VC, open-drain
for TC54VN).
V
IN
V
DET
+
V
HYST
Release Voltage
or RESET Voltage
Detect Voltage V
DET
–
Minimum Operating
Voltage
Ground Level
V
OUT
Output Voltage
Ground Level
FIGURE 3-1:
Timing Diagram.
2004 Microchip Technology Inc.
DS21434G-page 5
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