4-279
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
TC54
FEATURES
■Precise Detection Thresholds .... Standard ± 2.0%
Custom ± 1.0%
■Small Packages ...........SOT-23A-3, SOT-89, TO-92
■Low Current Drain .....................................Typ. 1µA
■Wide Detection Range..........................2.1V to 6.0V
■Wide Operating Voltage Range ............1.5V to 10V
APPLICATIONS
■Battery Voltage Monitoring
■Microprocessor Reset
■System Brownout Protection
■Switching Circuit in Battery Backup
■Level Discriminator
GENERAL DESCRIPTION
The TC54 Series are CMOS voltage detectors, suited
especially for battery-powered applications because of their
extremely low 1µA operating current and small surface-
mount packaging. Each part is laser trimmed to the desired
threshold voltage which can be specified from 2.1V to 6.0V,
in 0.1V steps.
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.
In operation, the TC54's output (VOUT) remains in the
logic HIGH state as long as VIN is greater than the
specified threshold voltage (V–
DET). When VIN falls below
V–
DET, the output is driven to a logic LOW. VOUT remains
LOW until VIN rises above V–
DET by an amount VHYST,
whereupon it resets to a logic HIGH.
FUNCTIONAL BLOCK DIAGRAM
VOLTAGE DETECTOR
Output form:
N = Nch Open Drain
C = CMOS Output
Detected Voltage:
Ex: 21 = 2.1V; 60 = 6.0V
Extra Feature Code: Fixed: 0
Tolerance:
1 = ± 1.0% (custom)
2 = ± 2.0% (standard)
Temperature: E: – 40°C to + 85°C
Package Type and Pin Count:
CB: SOT-23A-3*, MB: SOT-89-3, ZB: TO-92-3
Taping Direction:
Standard Taping
Reverse Taping
No suffix: TO-92 Bulk
*SOT-23A-3 is equivalent to EIAJ (SC-59).
ORDERING INFORMATION
PART CODE TC54 V X XX X X X XX XXX
TC54-10 11/8/96
VOUT
TC54VC only
VSS
1
3
+
–
VIN
2
VREF
TC54VN has open-drain output.
TC54VC has complementary output.
PIN CONFIGURATIONS
132
V
IN
VIN VSS
VIN
VSS
VOUT VSS VOUT
VOUT
TC54
TC54
TC54
1
1
2
3
32
*SOT-23A-3 SOT-89-3 TO-92
*SOT-23A-3 is equivalent to EIAJ (SC-59)
4-280 TELCOM SEMICONDUCTOR, INC.
TC54
VOLTAGE DETECTOR
ELECTRICAL CHARACTERISTICS: TA = 25°C, unless otherwise specified.
Symbol Parameter Test Conditions Min Typ Max Unit
VIN Operating Voltage V–
DET = 2.1 to 6.0V 1.5 10.0 V
ISS Quiescent Current VIN = 2.1V 1.0 3.0
3.0V 1.3 3.4 µA
4.0V 1.6 3.8
5.0V 2.0 4.2
V–
DET Threshold Voltage (V–
DET)(V
–
DET)V
x 0.98 x 1.02
VHYST Hysteresis Range (V–
DET)(V
–
DET)(V
–
DET)V
x 0.02 x 0.05 x 0.08
IOUT Output Current Nch VDS = 0.5 VIN = 2.1V 7.7 mA
3.0V 10.1
4.0V 11.5
5.0V 13.0
Pch VDS = 2.1V VIN = 8.0V – 10.0
TC (V–
DET) Tempco of (V–
DET) – 40°C ≤ TA ≤ 85°C± 100 ppm/°C
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage (VIN) ..................................................................... 12V
Output Voltage: CMOS ............ (VSS – 0.3) to (VIN + 0.3)
Open Drain................. (VSS – 0.3) to 12V
Output Current .........................................................50mA
Power Dissipation: (TA ≤ 70°C)
SOT-23A-3 .....................................................240mW
SOT-89-3 .......................................................400mW
TO-92 .......................................................440mW
Operating Temperature..........................– 40°C to + 85°C
Storage Temperature ...........................– 65°C to + 150°C
Soldering Temperature ...................... 300°C, 10 seconds
* 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.
Pin No. Symbol Description
1V
IN Analog input. This pin is both the power supply input and the voltage to be monitored.
2V
OUT Digital output. This output goes low when VIN drops below V–
DET and returns
high when VIN rises above V–
DET + VHYST. (See timing chart).
3V
SS Ground terminal.
PIN DESCRIPTION
4-281
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
TC54
VOLTAGE DETECTOR
TIMING CHART
MARKING
8
12
4
7
11
3
6
10
2
5
9
1
VIN
DETECT VOLTAGE VDET
MINIMUM OPERATING
VOLTAGE
VHYST
VDET
OUTPUT VOLTAGE
RELEASE
VOLTAGE RESET
VOLTAGE
OR
GROUND LEVEL
GROUND LEVEL
+
–
a = output (Nch or CMOS) plus first voltage digit
23456
Nch M N P R S
CMOS C D E F H
ex: CMOS 3.x = uuuu
b = first voltage decimal (0-9)
ex: CMOS 3.4 = uuuu
c & d = assembly lot number
D
D4
a, b & c = 54_ (fixed)
d = output (C = CMOS, N = Nch)
e = first voltage digit (2-6)
f = first voltage decimal (0-9)
g = extra feature code : fixed : 0
h = detecting accuracy
1 = ± 1.0% (custom), 2 = ± 2.0% (standard)
i, j, k & l = assembly lot number
SOT-89-3
SOT-23A-3 TO-92
DESCRIPTION OF OPERATION
Refer to the Timing Chart below. In normal steady-state
operation, when VIN > V–
DET, the output will be at a logic high.
In the case of the TC54V, this is an open-drain condition. If
and when the input falls below V–
DET, the output will pull down
(Logic 0) to VSS. Generally, VOUT can pull down to within
0.5V of VSS at rated output current and input voltage. (See
the Electrical Characteristics section).
The output, VOUT, will stay valid until the input voltage
falls below the Minimum Operating Voltage, VIN(MIN), of
1.5V. Below this minimum operating voltage, the output is
undefined. During power-up or anytime VIN has fallen below
VIN (MIN), VOUT will remain undefined until VIN rises above
VIN(MIN), at which time the output will become valid. VOUT
will be in its active low state while VIN(MIN) < VIN < V+
DET.
(V+
DET = V–
DET + VHYST). If and when the input rises above
V+
DET, the output will assume its inactive state. (High for
TC54VC, open-drain for TC54VN).
APPLICATIONS
Refer to TelCom Semiconductor Application Note #2,
Using the TC54 Voltage Detector
.
