TSM931-TSM934
Ultra Low-Power Single/Dual-Supply Comparators with Reference
FEATURES
DESCRIPTION
♦ Alternate source for MAX931-MAX934
♦ Ultra-Low Quiescent Current Over Temperature
TSM931 Single+Reference: 4μA (max)
TSM932/TSM933 Dual+Reference: 6μA (max)
TSM934 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
♦ Push-pull TTL/CMOS-Compatible Outputs
♦ Crowbar-Current-Free Switching
♦ Continuous Source Current Capability: 40mA
♦ Internal 1.182V ±2% Reference:
TSM931/TSM932/TSM933
♦ Adjustable Hysteresis:
TSM931/TSM932/TSM933
The TSM931–TSM934 family of single/dual/quad,
low-voltage, micropower analog comparators is
electrically and form-factor identical to the MAX931MAX934 family of analog comparators. Ideal for 3V or
5V single-supply applications, the TSM931–TSM934
family can operate from single +2.5V to +11V
supplies or from ±1.25V to ±5.5V dual supplies. The
single TSM931 draws less than 4μA (max) supply
current over temperature. The dual TSM932/933 and
the quad TSM934 each 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. In addition, the comparators’
push-pull output stages are TTL/CMOS compatible
and capable of sinking and sourcing current. The
TSM931/TSM932/TSM933 each incorporates an
internal 1.182V ±2% voltage reference. Without
complicated feedback configurations and only
requiring two additional resistors, adding external
hysteresis via a separate pin is available on the
TSM931, the TSM932, and the TSM933.
TYPICAL APPLICATION CIRCUIT
A 5V, Low-Parts-Count Window Detector
PART
TSM931
TSM932
TSM933
TSM934
INTERNAL COMPARATORS INTERNAL
REFERENCE PER PACKAGE HYSTERESIS
Yes
1
Yes
Yes
2
Yes
Yes
2
Yes
Yes
4
No
PART
TSM931C
TSM931E
TSM932C
TSM932E
TSM933C
TSM933E
TSM934C
TSM934E
TEMPERATURE
PACKAGE
RANGE
0ºC to 70ºC
8-Pin MSOP/SOIC
-40ºC to 85ºC
0ºC to 70ºC
8-Pin MSOP/SOIC
-40ºC to 85ºC
0ºC to 70ºC
8-Pin MSOP/SOIC
-40ºC to 85ºC
0ºC to 70ºC
16-Pin SOIC
-40ºC to 85ºC
Page 1
© 2014 Silicon Laboratories, Inc. All rights reserved.
TSM931-TSM934
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 (TSM931/934)...........................(V+ + 0.3V) to (GND - 0.3V)
OUT (TSM932/933)...............................(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
TSM93xC..................................................................0°C to +70°C
TSM93xE...............................................................-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
TSM931CUA+
Tube
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM931CSA+
Tube
97
TSM931CSA+T
Tape
& Reel
2500
TSM931ESA+
Tube
97
Tape
& Reel
2500
50
TS931
TAAX
TSM931CUA+T
Page 2
Tape
& Reel
2500
TS931E
TSM931ESA+T
TSM931/34 Rev. 1.0
TSM931-TSM934
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM932CUA+
Tube
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM932CSA+
Tube
97
Tape
& Reel
2500
Tube
97
TSM932ESA+T
Tape
& Reel
2500
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
TSM933CSA+
Tube
97
Tape
& Reel
2500
Tube
97
Tape
& Reel
2500
50
TS932
TSM932CSA+T
TABD
Tape
& Reel
TSM932CUA+T
ORDER NUMBER
TSM932ESA+
2500
PART
CARRIER QUANTITY
MARKING
TSM933CUA+
Tube
TS932E
50
TS933
TSM933CSA+T
TABB
TSM933CUA+T
TSM931/34 Rev. 1.0
Tape
& Reel
TSM933ESA+
2500
TS933E
TSM933ESA+T
Page 3
TSM931-TSM934
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
PART
CARRIER QUANTITY
MARKING
ORDER
NUMBER
Tube
TSM934ESE+
TSM934CSE+
TS934
TSM934CSE+T
Tape
& Reel
48
PART
CARRIER QUANTITY
MARKING
TS934E
2500
TSM934ESE+T
Tube
48
Tape
& Reel
2500
Lead-free Program: Silicon Labs supplies only lead-free packaging.
Consult Silicon Labs for products specified with wider operating temperature ranges.
Page 4
TSM931/34 Rev. 1.0
TSM931-TSM934
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
Supply Current
CONDITIONS
MIN
See Note 2
IN+ = IN- + 100mV
2.5
TSM931;
HYST = REF
TSM932
HYST = REF
TSM933
HYST = REF
TSM934
COMPARATOR
Input Offset Voltage
Input Leakage Current (IN-, IN+)
Input Leakage Current (HYST)
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
Response Time
Output High Voltage
Output Low Voltage
TYP
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
2.5
3.1
3.1
5.5
VCM = 2.5V
IN+ = IN- = 2.5V
TA = -40°C to +85°C
TSM931, TSM932, TSM933
±0.01
±0.02
V-
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
TSM931, TSM932, TSM933
0.1
0.1
20
REF- 0.05V
Overdrive = 10mV
TA = +25°C; 100pF load
Overdrive = 100mV
TA = -40°C to +85°C: IOUT = 17mA
TA = -40°C to +85°C: TSM932, TSM933
IOUT = 1.8mA
TSM931, TSM934
MAX
UNITS
11
3.2
4
4.5
6
4.5
6
6.5
8.5
V
μA
±10
±5
V+ – 1.3V
1
1
REF
12
4
mV
nA
nA
V
mV/V
mV/V
μVRMS
V
μs
V+ – 0.4
V- + 0.4
GND + 0.4
V
V
V
1.206
1.217
V
V
REFERENCE
Reference Voltage
TA = 0°C to +70°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
Source Current
Sink Current
Voltage Noise
TSM931/34 Rev. 1.0
100Hz to 100kHz
1.158
1.147
15
6
8
4
1.182
25
μA
15
μA
100
μVRMS
Page 5
TSM931-TSM934
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
Supply Current
CONDITIONS
IN+ = IN- + 100mV
MIN
TSM931;
HYST = REF
TSM932
HYST = REF
TSM933
HYST = REF
TSM934
COMPARATOR
Input Offset Voltage
Input Leakage Current (IN-, IN+)
Input Leakage Current (HYST)
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
TSM931, TSM932, TSM933
Response Time
TA = +25°C; 100pF load
Output High Voltage
Output Low Voltage
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TYP
MAX
UNITS
2.4
3
3.8
4.3
5.8
4.3
5.8
6.2
8
μA
3.4
3.4
5.2
VCM = 1.5V
IN+ = IN- = 1.5V
TA = -40°C to +85°C
TSM931, TSM932, TSM933
±0.01
±0.02
V0.2
0.1
20
REF- 0.05V
Overdrive = 10mV
Overdrive = 100mV
TA = -40°C to +85°C: IOUT = 10mA
TA = -40°C to +85°C: TSM932, TSM933
IOUT = 0.8mA
TSM931, TSM934
±10
±1
V+ – 1.3V
1
1
REF
14
5
mV
nA
nA
V
mV/V
mV/V
μVRMS
V
μs
V+ – 0.4
V- + 0.4
GND + 0.4
V
V
V
REFERENCE
Reference Voltage
Source Current
Sink Current
TA = 0°C to +70°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
TA = +25°C
TA = -40°C to +85°C
1.158
1.147
15
6
8
4
1.182
1.206
1.217
25
μA
15
μA
Voltage Noise
100Hz to 100kHz
100
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 (TSM934 Only)” section.
Page 6
V
μVRMS
TSM931/34 Rev. 1.0
TSM931-TSM934
TYPICAL PERFORMANCE CHARACTERISTICS
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
Output Voltage High vs
Load Current
Output Voltage Low
vs Load Current
2.5
5
V+ = 5V
V+ = 5V
4.5
2
4
V+ = 3V
VOH - V
VOL - V
1.5
1
3.5
3
2.5
V+ = 3V
0.5
2
0
1.5
0
4
8
12
16
20
24
0
28
10
LOAD CURRENT - mA
40
50
Reference Voltage vs Temperature
1.22
1.190
V+ = 3V or 5V
SINK
1.21
REFERENCE VOLTAGE - V
1.185
REFERENCE VOLTAGE - V
30
LOAD CURRENT - mA
Reference Output Voltage vs
Output Load Current
1.180
1.175
1.170
SOURCE
1.165
1.160
1.155
1.20
1.19
1.18
1.17
1.16
1.15
1.14
5
0
10
15
20
25
30
-40
-15
10
35
60
LOAD CURRENT - µA
TEMPERATURE - ºC
TSM931 Supply Current vs
Temperature
TSM932 Supply Current vs
Temperature
85
4.5
4.5
IN+ = IN- + 100mV
IN+ = IN- + 100mV
4
SUPPLY CURRENT - µA
4
SUPPLY CURRENT - µA
20
V+ = 5V, V- = -5V
3.5
3
V+ = 3V, V- = 0V
2.5
2
V+ = 10V, V- = 0V
3.5
V+ = 5V, V- = 0V
3
2.5
2
V+ = 3V, V- = 0V
V+ = 5V, V- = 0V
1.5
1.5
-40
-15
10
35
60
TEMPERATURE - ºC
TSM931/34 Rev. 1.0
85
-40
-15
10
35
60
85
TEMPERATURE - ºC
Page 7
TSM931-TSM934
TYPICAL PERFORMANCE CHARACTERISTICS
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
TSM933 Supply Current vs
Temperature
TSM934 Supply Current vs
Temperature
5
10
4.5
9
SUPPLY CURRENT - µA
SUPPLY CURRENT - µA
IN+ = IN- + 100mV
4
V+ = 5V, V- = 0V
3.5
3
V+ = 3V, V- = 0V
2.5
V+ = 5V, V- = -5V
8
7
V+ = 5V, V- = 0V
6
5
V+ = 3V, V- = 0V
4
2
3
-40
-15
10
35
60
-40
85
-15
TEMPERATURE - ºC
35
60
85
TEMPERATURE - ºC
TSM934 Supply Current vs
Low Supply Voltages
Hysteresis Control
80
10
60
OUTPUT HIGH
40
IN+ - IN- - mV
SUPPLY CURRENT - µA
10
1
20
0
NO CHANGE
-20
-40
OUTPUT LOW
-60
-80
0.1
1.5
0
2.5
2
10
20
30
40
SINGLE-SUPPLY VOLTAGE - V
VREF - VHYST - mV
Transfer Function
Response Time vs
Load Capacitance
50
18
5
V- = 0V
16
RESPONSE TIME - µs
OUTPUT VOLTAGE - V
4
3
2
1
14
12
VOHL
10
8
VOLH
6
4
2
0
-0.4 -0.3 -0.2 -0.1
0
0.1 0.2 0.3
IN+ INPUT VOLTAGE - mV
Page 8
0.4
0
20
40
60
80
100
LOAD CAPACITANCE - nF
TSM931/34 Rev. 1.0
TSM931-TSM934
TYPICAL PERFORMANCE CHARACTERISTICS
INPUT VOLTAGE - mV OUTPUT VOLTAGE - V
Response Time For Various
Input Overdrives (Low-to-High)
5
100mV
20mV
4
3
2
1
50mV
10mV
0
100
0
-2
0
2 4
6
8 10 12 14 16 18 20
INPUT VOLTAGE - mV OUTPUT VOLTAGE - V
V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted.
Response Time For Various
Input Overdrives (High-to-Low)
5
50mV
4
3
2
1
100
0
-2
0
2
4
6
8 10 12 14 16 18
RESPONSE TIME - µs
TSM934 Source and Sink Current at
Low Supply Voltages
TSM934 Response Time at
Low Supply Voltages (Low-to-High)
100
CURRENT - mA
100
RESPONSE TIME - µs
20mV
100mV
0
RESPONSE TIME - µs
±20mV OVERDRIVE
10
±100mV OVERDRIVE
1
SOURCE CURRENT INTO
0.75V LOAD
10
SINK CURRENT AT
VOUT = 0.4V
1
1.5
2
1.5
2.5
2.5
2
SINGLE-SUPPLY VOLTAGE - V
SINGLE-SUPPLY VOLTAGE - V
Short-Circuit Source Current vs
Supply Voltage
Short-Circuit Sink Current vs
Supply Voltage
200
24
OUT CONNECTED TO V+
GND CONNECTED TO V-
160
120
OUT CONNECTED TO V80
40
0
SINK CURRENT - mA
SOURCE CURRENT - mA
10mV
22
20
18
16
2
2.5
3
3.5
4
4.5
5
TOTAL SUPPLY VOLTAGE - V
TSM931/34 Rev. 1.0
5.5
2
4
6
8
10
TOTAL SUPPLY VOLTAGE - V
Page 9
TSM931-TSM934
PIN FUNCTIONS
TSM931
PIN
TSM932
TSM933
1
—
—
GND
—
1
1
OUTA
2
3
—
4
—
—
2
—
3
—
4
—
2
—
3
—
—
4
VIN+
INA+
ININB+
INB-
5
5
5
HYST
6
7
6
7
6
7
REF
V+
8
—
—
OUT
—
8
8
OUTB
PIN
TSM934
NAME
1
OUTB
2
OUTA
3
4
5
6
7
8
V+
INAINA+
INBINB+
REF
9
V-
10
11
12
13
14
INCINC+
INDIND+
GND
15
OUTD
16
OUTC
Page 10
NAME
FUNCTION
Ground. Connect to V- for single-supply operation. Output swings
from V+ to GND.
Comparator A Output. Sinks and sources current. Swings from
V+ to V-.
Negative Supply. Connect to ground for single-supply operation.
Comparator Noninverting Input
Comparator A Noninverting Input
Comparator Inverting Input
Comparator B Noninverting Input
Comparator B Inverting Input
Hysteresis Input. Connect to REF if not used. Input voltage range
is from VREF to (VREF - 50mV).
1.182V Reference Output with respect to V-.
Positive Supply Voltage
Comparator Output. Sinks and sources current. Swings from V+
to GND.
Comparator B Output. Sinks and sources current. Swings from
V+ to V-.
FUNCTION
Comparator B Output. Sinks and sources current. Swings
from V+ to GND.
Comparator A Output. Sinks and sources current. Swings
from V+ 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 singlesupply 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 and sources current. Swings
from V+ to GND.
Comparator C Output. Sinks and sources current. Swings
from V+ to GND.
TSM931/34 Rev. 1.0
TSM931-TSM934
BLOCK DIAGRAMS
TSM931/34 Rev. 1.0
Page 11
TSM931-TSM934
THEORY OF OPERATION
recommended to evaluate the circuit over the entire
power supply range and temperature.
The TSM931–TSM934 family of single/dual/quad,
low-voltage, micropower analog comparators
provide excellent flexibility and performance while
sourcing continuously up to 40mA of current. The
TSM931-TSM934 provide an on-board 1.182V ±2%
reference voltage. To minimize glitches that can
occur with parasitic feedback or a less than optimal
board layout, the design of the TSM931-TSM934
output stage is optimized to eliminate crowbar
glitches as the output switches. To minimize current
consumption while providing flexibility, the
TSM931-TSM933 have an on-board HYST pin in
order to add additional hysteresis.
Comparator Output
Power-Supply and Input Signal Ranges
The TSM931-TSM934 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 TSM931 and
the TSM934 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 TSM931 and the TSM934 are compatible
with TTL/CMOS with a ±5V voltage and the TSM932
and the TSM933 are compatible with TTL with a
single +5V supply.
Low-Voltage Operation: V+ = 1.5V (TSM934 Only)
Due to a decrease in propagation delay and a
reduction in output drive, the TSM931-TSM933
cannot be used with a supply voltage much lower
than 2.5V. However, the TSM934 can operate down
to a supply voltage of 2V; however, as the supply
voltage reduces, the TSM934 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
Page 12
The TSM931 and the TSM934 have a GND pin that
allows the output to swing from V+ to GND while the
V- pin can be set to a voltage below GND as long as
the voltage difference between V+ and V- is within
11V. Having a different voltage on V- will not affect
the output swing. For TTL applications, V+ can be
set to +5V±10% and V- can be set anywhere
between 0V and -5V±10%. On the other hand, the
TSM932 and the TSM933 do not have a GND pin;
hence, for TTL applications, V+ needs to be set to a
+5V power supply and V- to 0V. Furthermore, the
output design of the TSM931-TSM934 can source
and sink more than 40mA and 5mA, respectively,
while simultaneously maintaining a quiescent current
in the microampere range. If the power dissipation of
the package is maintained within the max limit, the
output can source pulses of 100mA of current with
V+ set to +5V. In an effort to minimize external
component count needed to address power supply
feedback, the TSM931-TSM934 output does not
produce crowbar switching current as the output
switches. With a 100mV input overdrive, the
propagation delay of the TSM931-TSM934 is 4μs.
Voltage Reference
The TSM931-TSM934 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 15μA and 8μA 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 TSM931-TSM934. 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 TSM931-TSM934 produces a
peak-to-peak noise of about 0.3mVPP while the
reference voltage produces a peak-to-peak noise of
about 1mVPP. 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.
TSM931/34 Rev. 1.0
TSM931-TSM934
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,
hysteresis effectively forces one comparator input to
move quickly past the other input, moving the input
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.
Figure 2. Programming 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 =
VHB
2 x IREF
1.182 R2 =
Figure 1. Threshold Hysteresis Band
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
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:
Hysteresis (TSM931-TSM933)
R1(kΩ) = VHB(mv)
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
For the TSM932-TSM933, the hysteresis is the
same for both comparators.
TSM931/34 Rev. 1.0
Hysteresis (TSM934)
Relative to adding hysteresis with the HYST pin as
was done for the TSM931-TSM933, the circuit in
Figure 3 uses positive feedback along with two
external resistors to set the desired hysteresis. The
circuit consumes more current and it slows down the
hysteresis effect due to the high impedance on the
Page 13
TSM931-TSM934
R2 =
=
1
1 1
VTHR
VREF x R1 R1 R3
1
3
1
1
1.182V x 100kΩ 100kΩ 10MΩ
= 65.44kΩ
In this example, a 64.9kΩ, 1% standard
value resistor is selected for R2.
Figure 3. External Hysteresis
feedback. The following procedure explains the
steps to design the circuit for a desired hysteresis:
1. Choosing R3. As the leakage current at the
IN+ pin is less than 1nA, the current through
R3 should be at least 100nA to minimize
offset voltage errors caused by the input
leakage current. For R3 = 11.8MΩ, the
current through R3 is VREF/R3 at the trip
point. In this case, a 10MΩ resistor is a good
standard value for R3.
2. Next, the desired hysteresis band ( VHB) is
set. In this example, VHB is set to 50mV.
3. Calculating R1.
R1 = R3 x
VHB
V+
= 10MΩ x
50mV
5V
= 100kΩ
In this example, a 100kΩ, 1% standard
value resistor is selected for R1.
4. Choose the trip point for VIN rising (VTHR),
which is the threshold voltage at which the
comparator switches its output from low to
high as VIN rises above the trip point. In this
example, choose VTHR = 3V.
5. Calculating R2.
Page 14
6. The last step is to verify the trip voltages and
hysteresis band using the standard
resistance values:
VTHR = VREF x R1 x
VTHF = VTHR –
1
1
1
+
+
R1 R2 R3
R1 x V+
R3
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
Auto-Off Power Source
A timed auto power-off circuit can be designed as
shown in Figure 4 where the output of the TSM931
is the switched power-supply output. With an internal
reference, hysteresis, high current output, and a 2.5
μA supply current, the TSM931 provides a wealth of
features that make it perfect for this application.
While consuming only 3.5μA of quiescent current
with a 10mA load, the TSM931 is able to generate a
voltage of VBATT – 0.12V. As shown in the figure,
three resistors are used to generate a hysteresis
band of 100mV and sets the IN+ trip point to 50mV
when IN+ is going low. The maximum power-on
period of the OUT pin before power-down occurs
TSM931/34 Rev. 1.0
TSM931-TSM934
respectively. If both OUTA and OUTB signals are
ANDed together, the resulting output of the AND
gate 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
(TSM931-TSM933)”, determine the desired
hysteresis and select resistors R4 and R5
accordingly. This circuit has ±5mV of
hysteresis at the input where the input
voltage VIN will appear larger due to the
input resistor divider.
Figure 4. Auto-Off Power Switch Operates on 2.5µA
quiescent current.
can be determined by the RC time constant as
follows:
R x C X 4.6 s
The period value will change depending on the
leakage current and the voltage applied to the
circuit. For instance: 2MΩ x 10μF x 4.6 s = 92 s.
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:
Window Detector
The schematic shown in Figure 5 is for a 4.5V
undervoltage threshold detector and a 5.5V
overvoltage threshold detector using the TSM933.
Resistor components R1, R2, and R3 can be
R2 + R3 = R1 x
= 294kΩ x
VOTH
-1
VREF +VHYS
5.5V
-1
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
Figure 5. Window Detector
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,
TSM931/34 Rev. 1.0
VREF -VHYS
- 294k
VUTH
1.182V-5mV
- 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
Page 15
TSM931-TSM934
= 1.068MΩ – 61.9kΩ
Bar-Graph Level Gauge
= 1.006MΩ
A simple four-stage level detector is shown in
Figure 6 using the TSM934. Due to its high output
source capability, the TSM921 is perfect for driving
LEDs. When all of the LEDs are on, the threshold
voltage is given as VIN =(R1 + R2)/R1 volts. All other
threshold voltages are scaled down accordingly by
¾, ½, and ¼ the threshold voltage. The current
through the LEDs is limited by the output resistors.
In this example, a 1MΩ, 1% standard value
resistor is selected for R3.
6. Using the equations below, verify all resistor
values selected:
R1 + R2 + R3
VOTH = (VREF + VHYS ) x
R1
Level Shifter
= 5.474V
VOTH = (VREF
R1 + R2 + R3
- VHYS ) x
(R1+R2)
= 4.484V
Where the hysteresis voltage is given by:
R5
VHYS = VREF x
R4
Figure 6. Bar-Graph Level Gauge
Page 16
Figure 7 provides a simple way to shift from bipolar
±5V inputs to TTL signals by using the TSM934. To
protect the comparator inputs, 10kΩ resistors are
placed in series and do not have an effect on the
performance of the circuit.
Two-Stage Low-Voltage Detector
A two step, input voltage monitoring circuit can be
designed using the TSM932 as shown in Figure 8. In
this circuit, when VIN is above the LOW and FAIL
thresholds, the outputs will be HIGH. The design
procedure used to design the window detector can
be used to design this circuit.
Figure 7. Level Shifter: ±5V Input into CMOS output
TSM931/34 Rev. 1.0
TSM931-TSM934
Figure 8. Two-Stage Low-Voltage Detector
TSM931/34 Rev. 1.0
Page 17
TSM931-TSM934
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 18
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.
TSM931/34 Rev. 1.0
TSM931-TSM934
PACKAGE OUTLINE DRAWING
8-Pin MSOP Package Outline Drawing
(N.B., Drawings are not to scale)
TSM931/34 Rev. 1.0
Page 19
TSM931-TSM934
PACKAGE OUTLINE DRAWING
16-Pin SOIC Package Outline Drawing
(N.B., Drawings are not to scale)
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