TSM971/72/73/82/84
Ultra-Low-Power, Open-Drain Single/Dual-Supply Comparators
FEATURES
DESCRIPTION
♦ Alternate source for:
MAX971/MAX972/MAX973/MAX982/MAX984
♦ Ultra-Low Quiescent Current Over Temperature
TSM971 Single+Reference: 4μA (max)
TSM972: Dual Comparator Only: 4μA (max)
TSM973/TSM982 Dual+Reference: 6μA (max)
TSM984 Quad+Reference: 8.5μA (max)
♦ Single or Dual Power Supplies:
Single: +2.5V to +11V
Dual: ±1.25V to ±5.5V
♦ Input Voltage Range Includes Negative Supply
♦ 12μs Propagation Delay at 10mV Overdrive
♦ Open-drain Output Stages for Wired-OR
Applications
♦ Internal 1.182V±1% Reference: TSM971/TSM973
♦ Internal 1.182V±2% Reference: TSM982/TSM984
♦ Adjustable Hysteresis: TSM971/TSM973/TSM982
♦ Separate Output GND Pin: TSM971/TSM984
The
TSM971/972/973/982/984
family
of
single/dual/quad, low-voltage, micropower analog
comparators is electrically and form-factor identical to
the MAX971/972/973/982/984 family of analog
comparators. Ideal for 3V or 5V single-supply
applications, this comparator family can operate from
single +2.5V to +11V supplies or from ±1.25V to
±5.5V dual supplies. The single TSM971 and the dual
TSM972 draw less than 4μA (max) supply current
over temperature. The TSM973/TSM982 duals and
the quad TSM984 draw less than 3μA per comparator
over temperature.
APPLICATIONS
Threshold Detectors
Window Comparator
Level Translators
Oscillator Circuits
Battery-Powered Systems
All comparators in this family exhibit an input voltage
range from the negative supply rail to within 1.3V of
the positive supply. Wired-OR applications are
enabled as the comparators’ output stages are opendrain. A 1.182V reference is internal to the
TSM971/TSM973 (±1%) and the TSM982/TSM984
(±2%). Without complicated feedback configurations
and only requiring two additional resistors, adding
external hysteresis is available on the TSM971,
TSM973, and the TSM982.
TYPICAL APPLICATION CIRCUIT
A 5V, Low-Parts-Count Window Detector
PART
TSM971
TSM972
TSM973
TSM982
TSM984
INTERNAL COMPARATORS INTERNAL
REFERENCE PER PACKAGE HYSTERESIS
Yes, ±1%
1
Yes
No
2
No
Yes, ±1%
2
Yes
Yes, ±2%
2
Yes
Yes, ±2%
4
No
PART
TSM971C
TSM971E
TSM972C
TSM972E
TSM973C
TSM973E
TSM982C
TSM982E
TSM984C
TSM984E
TEMPERATURE
RANGE
0ºC to 70ºC
-40ºC to 85ºC
0ºC to 70ºC
-40ºC to 85ºC
0ºC to 70ºC
-40ºC to 85ºC
0ºC to 70ºC
-40ºC to 85ºC
0ºC to 70ºC
-40ºC to 85ºC
PACKAGE
8-Pin MSOP/SOIC
8-Pin MSOP/SOIC
8-Pin MSOP/SOIC
8-Pin MSOP/SOIC
16-Pin SOIC
Page 1
© 2014 Silicon Laboratories, Inc. All rights reserved.
TSM971/72/73/82/84
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V+ to V-, V+ to GND, GND to V-)......-0.3V, +12V
Voltage Inputs
(IN+, IN-)..............................................(V+ + 0.3V) to (V- - 0.3V)
HYST…………………………………….(REF + 5V) to (V- - 0.3V)
Output Voltage
REF..................................................... (V+ + 0.3V) to (V- - 0.3V)
OUT (TSM971, TSM984).................(V+ + 0.3V) to (GND - 0.3V)
OUT (TSM972/73, TSM982/84).... ......(V+ + 0.3V) to (V- - 0.3V)
Input Current (IN+, IN-, HYST)..............................................20mA
Output Current
REF…………………………………………………………….20mA
OUT…………………………………………………………….50mA
Output Short-Circuit Duration (V+ ≤ 5.5V) ...................Continuous
Continuous Power Dissipation (TA = +70°C)
8-Pin MSOP (derate 4.1mW/°C above +70°C) .................330mW
8-Pin SOIC (derate 5.88mW/°C above +70°C)..................471mW
16-Pin SOIC (8.7mW/°C above +70°C) ............................696mW
Operating Temperature Range
TSM97xC..................................................................0°C to +70°C
TSM98xE...............................................................-40°C to +85°C
Storage Temperature Range .................................-65°C to +150°C
Lead Temperature (soldering, 10s) ......................................+300°C
Electrical and thermal stresses beyond 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 condition beyond those indicated in the operational sections
of the specifications is not implied. Exposure to any absolute maximum rating conditions for extended periods may affect device reliability and
lifetime.
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM971CUA+
Tube
50
TAAZ
TSM971CUA+T
Page 2
Tape
& Reel
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM971CSA+
Tube
97
Tape
& Reel
2500
Tube
97
Tape
& Reel
2500
TSM971CSA+T
TS971
TSM971ESA+
2500
TSM971ESA+T
TS971E
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM972CUA+
Tube
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM972CSA+
Tube
97
Tape
& Reel
2500
Tube
97
TSM972ESA+T
Tape
& Reel
2500
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
50
TS972
TSM972CSA+T
TABJ
Tape
& Reel
TSM972CUA+T
TSM972ESA+
2500
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM973CUA+
Tube
50
Tape
& Reel
2500
TS972E
TSM973CSA+
TABE
TSM973CUA+T
TSM971/72/73/82/84 Rev. 1.0
TSM973CSA+T
TS973
TSM973ESA+
TSM973ESA+T
TS973E
Tube
97
Tape
& Reel
2500
Tube
97
Tape
& Reel
2500
Page 3
TSM971/72/73/82/84
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM982CSA+
TSM982CUA+
Tube
50
Tape
& Reel
2500
TABK
TSM982CUA+T
TSM982CSA+T
TS982
TSM982ESA+
TSM982ESA+T
TS982E
Tube
97
Tape
& Reel
2500
Tube
97
Tape
& Reel
2500
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
ORDER
NUMBER
PART
CARRIER QUANTITY
MARKING
TSM984CSE+
Tube
48
TSM984ESE+
Tube
48
Tape
& Reel
2500
TSM984ESE+T
Tape
& Reel
2500
TSM984CSE+T
TS984
TS984E
Lead-free Program: Silicon Labs supplies only lead-free packaging.
Consult Silicon Labs for products specified with wider operating temperature ranges.
Page 4
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
ELECTRICAL CHARACTERISTICS – 5V OPERATION
V+ = 5V, V- = GND = 0V; TA = -40ºC to +85ºC, unless otherwise noted. Typical values are at TA = +25ºC. See Note 1.
PARAMETER
POWER REQUIREMENTS
Supply Voltage Range
Output Voltage Range
CONDITIONS
MIN
See Note 2
2.5
0
TSM971;
HYST = REF
TSM972
Supply Current
IN+ = IN- + 100mV
TSM973
TSM982;
HYST = REF
Output Low Voltage
Output Leakage Current
REFERENCE
2.5
3.1
TA = -40°C to +85°C
5.5
±0.01
±0.02
V-
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
TSM971, TSM973, TSM982
Overdrive = 10 mV
TA = +25°C; 100pF load;
1MΩ Pullup to V+
Overdrive = 100 mV
0.1
0.1
20
REF- 0.05V
TA = +25°C; 100pF load; 1MΩ Pullup to V+. See Note 3
TSM9x2, TSM973
TSM971, TSM984
VOUT = 11V
TSM971, TSM973
TSM982, TSM984
Source Current
Sink Current
100Hz to 100kHz
TSM971/72/73/82/84 Rev. 1.0
UNITS
11
11
3.2
4
3.2
4
4.5
V
V
μA
1.170
1.158
1.158
1.147
15
6
8
4
6.5
8.5
±10
±5
V+ – 1.3V
1.0
1.0
REF
mV
nA
nA
V
mV/V
mV/V
μVRMS
V
12
4
μs
300
μs
IOUT = 1.8mA
IOUT = 1.8mA
TA = 0°C to +70°C, 1%
TA = -40°C to +85°C, 2%
TA = 0°C to +70°C, 2%
TA = -40°C to +85°C, 3%
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TSM
6
VCM = 2.5V
IN+ = IN- = 2.5V
C/E temp ranges
TSM971, TSM973, TSM982
Reference Voltage
Voltage Noise
2.5
TA = +25°C
TA = -40°C to +85°C
TSM984
COMPARATOR
Input Offset Voltage
Input Leakage Current (IN-, IN+)
Input Leakage Current (at HYST Pin)
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
Response Time
(High-to-Low Transition)
Response Time
(Low-to-High Transition)
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TYP
1.182
1.182
V- + 0.4
GND + 0.4
100
nA
1.194
1.206
1.206
1.217
V
V
V
V
V
25
μA
15
μA
100
μVRMS
Page 5
TSM971/72/73/82/84
ELECTRICAL CHARACTERISTICS – 3V OPERATION
V+ = 3V, V- = GND = 0V; TA = -40ºC to +85ºC, unless otherwise noted. Typical values are at TA = +25ºC. See Note 1.
PARAMETER
POWER REQUIREMENTS
CONDITIONS
MIN
TSM971;
HYST = REF
TSM972
Supply Current
IN+ = IN- + 100mV
TSM973
TSM982;
HYST = REF
Output Low Voltage
Output Leakage Current
REFERENCE
2.4
3.0
3.8
3.0
3.8
4.3
μA
3.4
5.8
5.2
±0.01
±0.02
V-
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
TSM971, TSM973, TSM982
Overdrive = 10 mV
TA = +25°C; 100pF load;
1MΩ Pullup to V+
Overdrive = 100 mV
0.2
0.1
20
REF- 0.05V
TA = +25°C; 100pF load; 1MΩ Pullup to V+. See Note 3
TSM9x2, TSM973
TSM971, TSM984
VOUT = 11V
TSM971, TSM973
TSM982, TSM984
Sink Current
UNITS
TA = -40°C to +85°C
VCM = 1.5V
IN+ = IN- = 1.5V
C/E temp ranges
TSM971, TSM973, TSM982
Reference Voltage
Source Current
TSM
2.4
TA = +25°C
TA = -40°C to +85°C
TSM984
COMPARATOR
Input Offset Voltage
Input Leakage Current (IN-, IN+)
Input Leakage Current (at HYST Pin)
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
Response Time
(High-to-Low Transition)
Response Time
(Low-to-High Transition)
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TYP
1.170
1.158
1.158
1.147
15
6
8
4
±10
±5
V+ – 1.3V
1.0
1.0
REF
mV
nA
nA
V
mV/V
mV/V
μVRMS
V
12
4
μs
300
μs
IOUT = 0.8mA
IOUT = 0.8mA
TA = 0°C to +70°C, 1%
TA = -40°C to +85°C, 2%
TA = 0°C to +70°C, 2%
TA = -40°C to +85°C, 3%
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
6.2
8.0
1.182
1.182
V- + 0.4
GND + 0.4
100
nA
1.194
1.206
1.206
1.217
V
V
V
V
V
25
μA
15
μA
Voltage Noise
100Hz to 100kHz
100
μVRMS
Note 1: All specifications are 100% tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed by
device characterization, not production tested.
Note 2: The TSM934 comparator operates below 2.5V. Refer to the “Low-Voltage Operation: V+ = 1.5V (TSM984 Only)” section.
Note 3: Low-to-high response time is due to a 1MΩ pullup resistor and a 100pF capacitive load, based after three time constants. A smaller
RC combination results in a faster response time.
Page 6
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
TYPICAL PERFORMANCE CHARACTERISTICS
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
Output Voltage Low
vs Load Current
Reference Output Voltage vs
Output Load Current
1.190
2.5
V+ = 3V or 5V
V+ = 5V
SINK
1.185
REFERENCE VOLTAGE - V
2
VOL - V
1.5
V+ = 3V
1
0.5
1.180
1.175
1.170
SOURCE
1.165
1.160
1.155
0
0
4
8
12
16
20
24
0
28
5
LOAD CURRENT - mA
10
15
20
25
30
LOAD CURRENT - µA
TSM971 Supply Current vs
Temperature
Reference Voltage vs Temperature
4.5
1.22
IN+ = IN- + 100mV
4
SUPPLY CURRENT - µA
REFERENCE VOLTAGE - V
1.21
1.20
1.19
1.18
1.17
1.16
1.15
V+ = 5V, V- = -5V
3.5
3
V+ = 3V, V- = 0V
2.5
2
V+ = 5V, V- = 0V
1.5
1.14
-40
-15
10
35
60
-40
85
-15
10
35
60
85
TEMPERATURE - ºC
TEMPERATURE - ºC
TSM973/982 Supply Current vs
Temperature
TSM972 Supply Current vs
Temperature
4.5
5
IN+ = IN- + 100mV
4.5
V+ = 10V, V- = 0V
3.5
V+ = 5V, V- = 0V
3
2.5
2
V+ = 3V, V- = 0V
SUPPLY CURRENT - µA
SUPPLY CURRENT - µA
4
4
V+ = 5V, V- = 0V
3.5
3
V+ = 3V, V- = 0V
2.5
2
1.5
-40
-15
10
35
TEMPERATURE - ºC
TSM971/72/73/82/84 Rev. 1.0
60
85
-40
-15
10
35
60
85
TEMPERATURE - ºC
Page 7
TSM971/72/73/82/84
TYPICAL PERFORMANCE CHARACTERISTICS
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
TSM984 Supply Current vs
Low Supply Voltages
TSM984 Supply Current vs
Temperature
10
10
IN+ = IN- + 100mV
SUPPLY CURRENT - µA
SUPPLY CURRENT - µA
9
V+ = 5V, V- = -5V
8
7
V+ = 5V, V- = 0V
6
5
V+ = 3V, V- = 0V
4
0.1
3
-40
-15
10
35
60
85
1.5
2
SINGLE-SUPPLY VOLTAGE - V
TSM971/973/982
Hysteresis Control
TSM971/972/984
Transfer Function
5
60
OUTPUT HIGH
4
OUTPUT VOLTAGE - V
40
20
0
NO CHANGE
-20
-40
OUTPUT LOW
-60
-80
3
2
1
0
0
20
10
30
40
50
-0.4 -0.3 -0.2 -0.1
18
V- = 0V
RESPONSE TIME - µs
16
14
VOHL
12
10
8
6
20
40
60
80
LOAD CAPACITANCE - nF
100
INPUT VOLTAGE - mV OUTPUT VOLTAGE - V
Response Time vs
Load Capacitance
0
0
0.1 0.2 0.3
0.4
IN+ INPUT VOLTAGE - mV
VREF - VHYST - mV
Page 8
2.5
TEMPERATURE - ºC
80
IN+ - IN- - mV
1
Response Time For Various
Input Overdrives (High-to-Low)
5
50mV
4
10mV
3
2
1
20mV
100mV
0
100
0
-2
0
2
4
6
8 10 12 14 16 18
RESPONSE TIME - µs
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
TYPICAL PERFORMANCE CHARACTERISTICS
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
TSM984 Sink Current at
Low Supply Voltages
Response Time at
Low Supply Voltages (Low-to-High)
10
100
SINK CURRENT AT
VOUT = 0.4V
CURRENT - mA
RESPONSE TIME - µs
RPULLUP = 10kΩ
±20mV OVERDRIVE
10
±100mV OVERDRIVE
1
1
1.5
2
1.5
2.5
SINGLE-SUPPLY VOLTAGE - V
2
2.5
SINGLE-SUPPLY VOLTAGE - V
Short-Circuit Sink Current vs
Supply Voltage
24
SINK CURRENT - mA
OUT CONNECTED TO V+
GND CONNECTED TO V22
20
18
16
2
TSM971/72/73/82/84 Rev. 1.0
4
6
8
10
Page 9
TSM971/72/73/82/84
PIN FUNCTIONS
TSM971
1
PIN
TSM972 TSM973
—
—
NAME
FUNCTION
TSM982
—
GND
Ground. Connect to V- for single-supply operation.
Negative Supply. Connect to ground for single-supply
operation (TSM971).
Comparator Noninverting Input
Comparator Inverting Input
Hysteresis Input. Connect to REF if not used. Input
voltage range is from VREF to (VREF - 50mV).
Reference Output. 1.182V with respect to V-.
Positive Supply Voltage
Comparator Output. Sinks current to GND.
Comparator A Output. Sinks current to V-.
Comparator A Noninverting Input
Comparator A Inverting Input
Comparator B Inverting Input
Comparator B Noninverting Input
Comparator B Output. Sinks current to V-.
2
2
2
2
V-
3
4
—
—
—
—
—
—
IN+
IN-
5
—
5
5
HYST
6
7
8
—
—
—
—
—
—
—
7
—
1
3
4
5
6
8
6
7
—
1
3
—
4
—
8
6
7
—
1
3
—
—
4
8
REF
V+
OUT
OUTA
INA+
INAINBINB+
OUTB
PIN
TSM984
1
2
3
4
5
6
7
8
Page 10
NAME
FUNCTION
OUTB
OUTA
V+
INAINA+
INBINB+
REF
Comparator B Output. Sinks current to GND.
Comparator A Output. Sinks current to GND.
Positive Supply Voltage
Comparator A Inverting Input
Comparator A Noninverting Input
Comparator B Inverting Input
Comparator B Noninverting Input
1.182V Reference Output with respect to V-.
Negative Supply Voltage. Connect to ground for
single-supply operation.
Comparator C Inverting Input
Comparator C Noninverting Input
Comparator D Inverting Input
Comparator D Noninverting Input
Ground. Connect to V- for single-supply operation.
Comparator D Output. Sinks current to GND.
Comparator C Output. Sinks current to GND.
9
V-
10
11
12
13
14
15
16
INCINC+
INDIND+
GND
OUTD
OUTC
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
BLOCK DIAGRAMS
TSM971/72/73/82/84 Rev. 1.0
Page 11
TSM971/72/73/82/84
THEORY OF OPERATION
The
TSM971/972/973/982/984
family
of
single/dual/quad, low-voltage, micropower analog
comparators provide excellent flexibility and
performance while sourcing continuously up to
40mA of current. The TSM971, TSM973, TSM982,
and the TSM984 provide an on-board 1.182V
reference voltage. To minimize current consumption
while providing flexibility, the TSM971, TSM973, and
the TSM982 have an on-board HYST pin in order to
add additional hysteresis.
Power-Supply and Input Signal Ranges
The TSM971/972/973/982/984 can operate from a
single supply voltage range of +2.5V to +11V,
provide a wide common mode input voltage range of
V- to V+-1.3V, and accept input signals ranging from
V- to V+ - 1V. The inputs can accept an input as
much as 300mV above the below the power supply
rails without damage to the part. While the TSM971
and the TSM984 are able to operate from a single
supply voltage range, a GND pin is available that
allows for a dual supply operation with a range of
±1.25V to ±5.5V. If a single supply operation is
desired, the GND pin needs to be tied to V-. In a
dual supply mode, the TSM971 and the TSM984 are
compatible with TTL/CMOS with a ±5V voltage and
the TSM972, TSM973, and TSM982 are compatible
with TTL with a single +5V supply.
Low-Voltage Operation: V+ = 1.5V (TSM984 Only)
Due to a decrease in propagation delay and a
reduction in output drive, the TSM971/972/973/982
cannot be used with a supply voltage much lower
than 2.5V. However, the TSM984 can operate down
to a supply voltage of 2V; furthermore, as the supply
voltage reduces, the TSM984 supply current drops
and the performance is degraded. When the supply
voltage drops to 2.2V, the reference voltage will no
longer function; however, the comparators will
function down to a 1.5V supply voltage.
Furthermore, the input voltage range is extended to
just below 1V the positive supply rail. For
applications with a sub-2.5V power supply, it is
recommended to evaluate the circuit over the entire
power supply range and temperature.
Comparator Output
The TSM971 and the TSM984 have a GND pin that
allows the output to swing from V+ to GND while the
Page 12
V- pin can be set to a voltage below GND as long as
the voltage difference between V+ and V- is within
11V. The TSM971 and the TSM984 sink current to
GND. By having open-drain outputs, the
TSM971/972/973/982/984 can be used in wireOREd and level-shifting applications. On the other
hand, the TSM972, TSM973, and the TSM982 do
not have a GND pin so the outputs sink current to V. With a 100mV input overdrive, the propagation
delay of the TSM971/972/973/982/984 is 4μs.
Voltage Reference
The TSM971/972/973 have an on-board 1.182V
reference voltage with an accuracy of ±1% while the
TSM982/984 have an on-board 1.182V reference
voltage with an accuracy of ±2% across a
temperature range of 0°C to +70°C. The REF pin is
able to source and sink 25μA and 15μA of current,
respectively. The REF pin is referenced to V- and it
should not be bypassed.
Noise Considerations
Noise can play a role in the overall performance of
the TSM971/972/973/982/984. Despite having a
large gain, if the input voltage is near or equal to the
input offset voltage, the output will randomly switch
HIGH
and
LOW.
As
a
result,
the
TSM971/972/973/982/984 produces a peak-to-peak
noise of about 0.3mV while the reference voltage
produces a peak-to-peak noise of about 1mV.
Furthermore, it is important to design a layout that
minimizes capacitive coupling from a given output to
the reference pin as crosstalk can add noise and as
a result, degrade performance.
APPLICATIONS INFORMATION
Hysteresis
As a result of circuit noise or unintended parasitic
feedback, many analog comparators often break into
oscillation within their linear region of operation
especially when the applied differential input voltage
approaches 0V (zero volt). Externally-introduced
hysteresis is a well-established technique to
stabilizing analog comparator behavior and requires
external components. As shown in Figure 1, adding
comparator hysteresis creates two trip points: VTHR
(for the rising input voltage) and VTHF (for the falling
input voltage). The hysteresis band (VHB) is defined
as the voltage difference between the two trip points.
When a comparator’s input voltages are equal,
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
hysteresis effectively forces one comparator input to
move quickly past the other input, moving the input
Figure 2. Programming the HYST Pin
Figure 1. Threshold Hysteresis Band
out of the region where oscillation occurs. Figure 1
illustrates the case in which an IN- input is a fixed
voltage and an IN+ is varied. If the input signals
were reversed, the figure would be the same with an
inverted output.
typically in the range of 0.1μA and 4μA. It is also
important to ensure that the current from reference is
much larger than the HYST pin input current. Given
R2 = 2.4MΩ, the current sourced by the reference is
0.5μA. This allows the hysteresis band and R1 to be
approximated as follows:
R1(kΩ) = VHB(mv)
Hysteresis (TSM971/973 and TSM982)
Hysteresis can be generated with two external
resistors using positive feedback as shown in
Figure 2. Resistor R1 is connected between REF
and HYST and R2 is connected between HYST and
V-. This will increase the trip point for the rising input
voltage, VTHR, and decrease the trip point for the
falling input voltage, VTHF, by the same amount. If no
hysteresis is required, connect HYST to REF. The
hysteresis band, VHB, is voltage across the REF and
HYST pin multiplied by a factor of 2. The HYST pin
can accept a voltage between REF and REF-50mV,
where a voltage of REF-50mV generates the
maximum voltage across R1 and thus, the maximum
hysteresis and hysteresis band of 50mV and
100mV, respectively. To design the circuit for a
desired hysteresis band, consider the equations
below to acquire the values for resistors R1 and R2:
R1 =
Hysteresis (TSM972 and TSM984)
Relative to adding hysteresis with the HYST pin as
was done for the TSM971, TSM973, and the
TSM982, the circuit in Figure 3 uses positive
feedback along with two external resistors to set the
desired hysteresis. The circuit consumes more
VHB
ሺ2 x IREF ሻ
1.182 R2 =
For the TSM973 and TSM982, the hysteresis is the
same for both comparators.
VHB
2
IREF
where IREF is the primary source of current out of the
reference pin and should be maintained within the
maximum current the reference can source. This is
TSM971/72/73/82/84 Rev. 1.0
Figure 3. External Hysteresis
current and it slows down the hysteresis effect due
to the high impedance on the feedback. Due to the
pull-up resistor on the output and its inability to
Page 13
TSM971/72/73/82/84
source current, upper threshold variations will
depend on the value of the pull-up resistor.
Board Layout and Bypassing
While power-supply bypass capacitors are not
typically required, it is good engineering practice to
use 0.1μF bypass capacitors close to the device’s
power supply pins when the power supply
impedance is high, the power supply leads are long,
or there is excessive noise on the power supply
traces. To reduce stray capacitance, it is also good
engineering practice to make signal trace lengths as
short as possible. Also recommended are a ground
plane and surface mount resistors and capacitors.
TYPICAL APPLICATION CIRCUITS
voltage VIN will appear larger due to the
input resistor divider.
2. Selecting R1. As the leakage current at the
INB- pin is less than 1nA, the current
through R1 should be at least 100nA to
minimize offset voltage errors caused by the
input leakage current. Values within 100kΩ
and 1MΩ are recommended. In this
example, a 294kΩ, 1% standard value
resistor is selected for R1.
3. Calculating R2 + R3. As the input voltage
VIN rises, the overvoltage threshold should
be 5.5V. Choose R2 + R3 as follows:
R2 + R3 = R1 x ൬
Window Detector
The schematic shown in Figure 4 is for a 4.5V
undervoltage threshold detector and a 5.5V
overvoltage threshold detector using the TSM973.
Resistor components R1, R2, and R3 can be
selected based on the threshold voltage desired
while resistors R4 and R5 can be selected based on
the hysteresis desired. Adding hysteresis to the
circuit will minimize chattering on the output when
the input voltage is close to the trip point. OUTA and
OUTB generate the active-low undervoltage
indication and active-low overvoltage indication,
respectively. If both OUTA and OUTB signals are
Wired-ORed, the resulting output is an active-high,
power-good signal. To design the circuit, the
following procedure needs to be performed:
1.
As described in the section “Hysteresis
(TSM971/973 and TSM982)”, determine the
desired hysteresis and select resistors R4
and R5 accordingly. This circuit has ±5mV of
hysteresis at the input where the input
= 294kΩ x ൬
VOTH
- 1൰
VREF +VHYS
5.5V
- 1൰
1.182V +5mV
= 1.068MΩ
4. Calculating R2. As the input voltage VIN falls,
the undervoltage threshold should be 4.5V.
Choose R2 as follows:
R2 = (R1 + R2+ R3) x
= (294kΩ + 1.068MΩ) x
ሺVREF -VHYS ሻ
- 294k
VUTH
ሺ1.182V-5mVሻ
- 294k
4.5
= 62.2kΩ
In this example, a 61.9kΩ, 1% standard
value resistor is selected for R2.
5. Calculating R3.
R3 = (R2 + R3) - R2
= 1.068MΩ – 61.9kΩ
= 1.006MΩ
In this example, a 1MΩ, 1% standard value
resistor is selected for R3.
6. Using the equations below, verify all resistor
values selected:
VOTH = (VREF + VHYS ) x
ሺR1 + R2 + R3ሻ
R1
Figure 4. Window Detector
Page 14
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
= 5.474V
VOTH = (VREF - VHYS ) x
ሺR1 + R2 + R3ሻ
(R1+R2)
= 4.484V
Where the hysteresis voltage is given by:
VHYS = VREF
R5
x
R4
Battery Switchover Circuit
Diodes are typically used in applications where
power to a device switches from a line-powered DC
to a backup battery. However, the voltage drop and
power loss across the diodes is undesired. Figure 5
shows a different approach that replaces the diode
with a P-channel MOSFET and uses the TSM973 to
control the MOSFET. When the voltage from the
line-powered DC drops below 4V, OUTA switches
low, and then turns on Q1. When the battery drops
below 3.6V, Comparator B generates a “low-battery”
signal.
Level Shifter
Figure 6 provides a simple way to shift from bipolar
±5V inputs to TTL signals by using the TSM984. To
protect the comparator inputs, 10kΩ resistors are
placed in series and do not have an effect on the
performance of the circuit.
Figure 6. Level Shifter: ±5V Input to Single-Ended 3.3V
Output
Figure 5. Battery Switchover Circuit
TSM971/72/73/82/84 Rev. 1.0
Page 15
TSM971/72/73/82/84
PACKAGE OUTLINE DRAWING
8-Pin SOIC Package Outline Drawing
(N.B., Drawings are not to scale)
0.546 REF
0.33 - 0.51
5.80 – 6.20
1.27 TYP
4.80 - 5.00
LEADFARME
THICKNESS
0.19 – 0.25
1
1.32 – 1.52
7' REF ALL SIDE
3.73 - 3.89
7' REF
ALL SIDE
2
0.48 Max
0.28 Min
45' Angle
0.76 Max
0.66 Min
1.75 Max
GAUGE PLANE
3.81 – 3.99
0.25
0.10 – 0.25
2
0 - 8°
0.406 – 0.863
0.10 Max
Notes:
Page 16
1
Does not include mold flash, protrusions or gate burns.
Mold flash, protrusions or gate burrs shall not exceed
0.15 mm per side.
2
Does not include inter-lead flash or protrusions. Inter-lead
flash or protrusions shall not exceed 0.25 mm per side.
3.
Lead span/stand off height/coplanarity are considered as
special characteristic (s).
4.
Controlling dimensions are in mm.
5.
This part is compliant with JEDEC specification MS-012
6.
Lead span/stand off height/coplanarity are considered as
Special characteristic.
TSM971/72/73/82/84 Rev. 1.0
TSM971/72/73/82/84
PACKAGE OUTLINE DRAWING
8-Pin MSOP Package Outline Drawing
(N.B., Drawings are not to scale)
TSM971/72/73/82/84 Rev. 1.0
Page 17
TSM971/72/73/82/84
PACKAGE OUTLINE DRAWING
16-Pin SOIC Package Outline Drawing
(N.B., Drawings are not to scale)
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