Datasheet - TS3121, TS3121A, TS3121P - Rail-to-rail, open-drain comparator with embedded Power-on Reset (P-version)
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 35
Technical content
Datasheet sections
- 1 Pin configuration
- 2 Maximum ratings
- 3 Electrical characteristics
- 4 Typical performance characteristics
- 5 Application information
- 6 Package information
- 6.1 SC70-5 (or SOT323-5) package information
- 6.2 SOT23-5 package information
- 7 Ordering information
Features
- AEC-Q100 qualified
- Low offset voltage: 2 mV max @ 25 °C (A-grade version)
- Low power consumption: 70 μA typ.
- Wide supply voltage: 1.7 to 5.5 V
- Propagation delay: 60 ns
- Rail-to-rail input
- Open-drain output
- Output pin withstands voltages higher than VCC
- Power-on Reset (TS3121P)
- Guaranteed start-up time (TS3121, TS3121A)
- High ESD tolerance: 4 kV HBM
- Extended temperature range: -40 to +125 °C
- Safety capable: documentation available to aid functional safety system design
Applications
- Industrial
- Automotive
- Power tools
- Overcurrent protection
- Controllers, sensors
Description
The TS3121, TS3121A and TS3121P single comparators permit high-speed response time at low power consumption over a supply voltage specified from 1.7 to 5.5 V. These devices operate over a wide temperature range from -40 °C to +125 °C making them ideal for industrial and automotive applications with the associated qualification. An embedded power-on reset circuit in the TS3121P version ensures a known output condition while activating the supply rail. Thanks to their small package size, the TS3121, TS3121A and TS3121P can be used in applications where space on the board is limited. It can thus reduce the overall cost of the PCB. SC70-5 SOT23-5 Maturity status link TS3121, TS3121A, TS3121P
Related products
TS880 For lower supply current TS3011 For higher speed TS3021 For push-pull output Rail-to-rail, open-drain comparator with embedded Power-on Reset (P-version) TS3121, TS3121A, TS3121P Datasheet DS14484 - Rev 4 - April 2026 For further information, contact your local STMicroelectronics sales office.
1 Pin configuration
Figure 1. Pin connection (top view) Table 1. Pin description
1 OUT Output
2 VCC- Negative supply voltage
3 IN+ Positive input voltage
4 IN- Negative input voltage
5 VCC+ Positive supply voltage
2 Maximum ratings
Table 2. Absolute maximum ratings
- All voltage values, except differential voltage, are with respect to the network ground terminal.
- Input current must be limited by a resistor in series with the inputs.
- Short circuits can cause excessive heating and destructive dissipation.
- According to JEDEC standard JESD22-A114F.
- According to ANSI/ESD STM5.3.1.
Table 3. Operating conditions
3 Electrical characteristics
Table 4. Electrical characteristics - VCC = 5 V, Vicm = VCC/2, T = 25 °C (unless otherwise specified).
Electrical characteristics
Symbol Parameter Conditions Min. Typ. Max. Unit tPHL (5) Propagation delay (high to low), CL = 15 pF, overdrive = 20 mV, VPU = VCC ns RPU = 2.5 kΩ, T = 25 °C Tmin < T < Tmax 100 135 185 CL = 15 pF, overdrive = 100 mV, VPU = VCC RPU = 2.5 kΩ, T = 25 °C Tmin < T < Tmax 60 85 125 tF Fall time (90% to 10%) CL = 15 pF, RPU = 2.5 kΩ, overdrive = 100 mV 2.5 1. Hysteresis is a built-in feature of the TS3121. It is defined as the voltage difference between the trip points. 2. Maximum values include unavoidable inaccuracies of the industrial tests. 3. Maximum high-level output leakage current at T = 25 °C is guaranteed by design. 4. tPLH is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM - 100 mV to VICM + overdrive. 5. tPHL is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM + 100 mV to VICM - overdrive. TS3121, TS3121A, TS3121P
Table 5. Electrical characteristics - VCC = 3.3 V, Vicm = VCC/2, T = 25 °C (unless otherwise specified).
Symbol Parameter Conditions Min. Typ. Max. Unit tF nsFall time (90% to 10%) CL = 15 pF, RPU = 2.5 kΩ, overdrive = 100 mV 3.5 1. Hysteresis is a built-in feature of the TS3121. It is defined as the voltage difference between the trip points. 2. Maximum values include unavoidable inaccuracies of the industrial tests. 3. Maximum high-level output leakage current at T = 25 °C is guaranteed by design. 4. tPLH is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM - 100 mV to VICM + overdrive. 5. tPHL is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM + 100 mV to VICM - overdrive. TS3121, TS3121A, TS3121P
Table 6. Electrical characteristics - VCC = 1.8 V, Vicm = VCC/2, T = 25 °C (unless otherwise specified).
Symbol Parameter Conditions Min. Typ. Max. Unit tF nsFall time (90% to 10%) CL = 15 pF, RPU = 2.5 kΩ, overdrive = 100 mV 3.5 1. Hysteresis is a built-in feature of the TS3121. It is defined as the voltage difference between the trip points. 2. Maximum values include unavoidable inaccuracies of the industrial tests. 3. Maximum high-level output leakage current at T = 25 °C is guaranteed by design. 4. tPLH is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM - 100 mV to VICM + overdrive. 5. tPHL is measured when the output signal crosses a voltage level at 50% of Vcc with the following conditions: inverting inputvoltage (IN-) = VICM and non-inverting input voltage (IN+) moving from VICM + 100 mV to VICM - overdrive. TS3121, TS3121A, TS3121P
4 Typical performance characteristics
Figure 2. Supply current vs. supply voltage at Vicm = VCC, Figure 3. Supply current vs. supply voltage at Figure 4. Supply current vs. supply voltage at Vicm = VCC-, Figure 5. Supply current vs. supply voltage at Vicm = VCC,
5 Application information
Input offset voltage drift versus temperature The input voltage drift variation versus temperature is defined as the offset variation related to the offset value measured at 25 °C. The signal chain accuracy at 25 °C can be compensated during the production at the application level. The maximum input voltage drift over the temperature enables the system designer to anticipate the effect of temperature variations. Δ V i o Δ V = max V io T − V i o 25 ° C T − 25 ° C (1) Where T = -40 °C and +125 °C. The datasheet maximum value is guaranteed by a measurement on a representative sample size ensuring a Cpk (process capability index) greater than 1.3. The datasheet reports the absolute worst-case value between -40 °C and +125 °C. Resistor values for high-speed design Figure 50. Rise time vs. pull-up resistor
Application information
DS14484 - Rev 4 page 22/35
PCB layout recommendations Particular attention must be paid to the layout of the PCB tracks connected to the comparator, load, and power supply. The power and ground traces are critical as they must provide adequate energy and grounding for all circuits. The best practice is to use short and wide PCB traces to minimize voltage drops and parasitic inductance. In addition to minimizing parasitic impedance over the entire surface, a multi-via technique that connects the bottom and top layer ground planes together in many locations is often used. The copper traces that connect the output pins to the load and supply pins should be as wide as possible to minimize trace impedance. Decoupling capacitor To ensure op amp full functionality, it is recommended to place two decoupling capacitors of 100 nF and 10 nF as close as possible to the comparator supply pins. A good decoupling helps to reduce electromagnetic interference impact. TS3121, TS3121A, TS3121P DS14484 - Rev 4 page 25/35
6 Package information
To meet environmental requirements, ST offers these devices in different grades of ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions, and product status are available at: www.st.com. ECOPACK is an ST trademark. TS3121, TS3121A, TS3121P
Package information
DS14484 - Rev 4 page 26/35
6.1 SC70-5 (or SOT323-5) package information
Figure 55. SC70-5 (or SOT323-5) package outline Table 7. SC70-5 (or SOT323-5) package mechanical data DS14484 - Rev 4 page 27/35
6.2 SOT23-5 package information
Figure 56. SOT23-5 package outline Table 8. SOT23-5 mechanical data DS14484 - Rev 4 page 28/35
7 Ordering information
Table 9. Order code
- Qualified and characterized according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 &
Ordering information
DS14484 - Rev 4 page 29/35
Revision history
Table 10. Document revision history 31-Jul-2024 1 Initial release. 14-Nov-2024 2 Updated description on the cover page. 10-Apr-2025 3 Updated Figure 1. Pin connection (top view). 03-Apr-2026 4 Updated features, added new part number TS3121P.
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