Datasheet - STEL12H24 - Electronic switch for 12 V, 5 V and 3.3 V buses
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 26
Technical content
Datasheet sections
- 1 Diagram
- 2 Pin configuration
- 3 Typical application circuit
- 4 Maximum ratings
- 5 Electrical characteristics
- 6 Application information
- 6.1 Enable pin
- 6.2 Undervoltage lockout
- 6.3 Quick discharge
- 6.4 Power Good
- 6.5 Short-circuit protection
- 6.6 Slew rate control
- 6.7 Overvoltage protection
- 6.8 Thermal shutdown
- 7 Typical characteristics
- 8 Package information
- 8.1 DFN12 (3 x 3 mm) package information
- 8.2 DFN12 (3 x 3 mm) packing information
- 9 Ordering information
Features
- Power Input voltage from 0.5 V to 13.5 V
- Analog input voltage from 3.0 V to 13.5 V
- 17 A max DC output current
- Embedded 4.5 mΩ N-channel MOSFET
- Internal output discharge path
- Power Good
- Soft-start controlled with external capacitor
- Undervoltage lockout
- Short-circuit protection
- Thermal protection
- Operating junction temperature range: -40 °C to 125 °C
Applications
- Bus protection
- Hot-swap and peripheral port protection
- Telecom, Networking and Industrial equipment
- Servers and Gateways
Description
The STEL12H24 is an integrated controlled inrush and overcurrent protection device optimized for power bus architectures. When connected to a 12 V, 5 V or 3.3 V power rail, it is able to limit the inrush current, detect input voltage faults and short-circuit conditions and signal these events via a Power Good output. The low RDSON value of the integrated MOSFET guarantees these conditions and low power dissipation during normal operation. The device is available in a DFN12 leads 3 x 3 mm. Maturity status link STEL12H24 Electronic switch for 12 V, 5 V and 3.3 V buses STEL12H24 Datasheet DS13821 - Rev 3 - June 2026 For further information, contact your local STMicroelectronics sales office.
1 Diagram
Figure 1. Block diagram
2 Pin configuration
Figure 2. Pin connection (top view) Table 1. Pin description 1 VIN MOSFET drain, to be connected to the thermal pad. 3 VCC Supply voltage for the control logic.
4 GND Ground
VOUT Source of the MOSFET. To be connected to the load. Thermal Pad VIN MOSFET drain.
3 Typical application circuit
Figure 3. Typical application Table 2. Typical application components
4 Maximum ratings
Table 3. Absolute maximum ratings Table 4. Thermal data
- JEDEC still air natural convection test as per JESD 51-2 A, at ambient temperature of 25 ºC by using JEDEC (JESD 51-7)
4L PCB FR4 board (with 2 PCB Thermal vias). Table 5. ESD performance
- Rating is for all pins except for VIN and VOUT which are tied to the internal MOSFET’s Drain and Source. Typical MOSFET
ESD performance for VIN and VOUT should be expected and these devices should be treated as ESD sensitive.
5 Electrical characteristics
VCC = 3.3 V, VIN = 12 V, CIN = 1 µF, COUT = 10 µF, VEN = 3.3 V, RPG = 100 kΩ, CSR = 100 nF, TJ = 25 °C unless otherwise specified. Table 6. Electrical characteristics
Electrical characteristics
Symbol Parameter Test conditions Min. Typ. Max. Unit VSC Short-circuit protection threshold VCC = 3 V; VIN = 0.5 V 240 260 280 mV VCC = 3 V; VIN = 13.5 V 240 260 280 OVP Overvoltage protection threshold 17 17.5 V TSHDN Thermal shutdown 145 Hysteresis 18 Figure 4. Switching characteristics test circuit Table 7. Switching characteristics table
Symbol Parameter Test conditions Min. Typ. Max. Unit TOFF Turn-off delay VCC = 3.3 V; VIN = 12 V µs 110 VCC = 5.0 V; VIN = 12 V 100 VCC = VIN = 3.3 V 100 VCC = VIN = 5.0 V 100 VCC = VIN = 12 V 100 TPG-ON Power Good turn-on time VCC = 3.3 V; VIN = 1.8 V 2.5 ms VCC = 5.0 V; VIN = 1.8 V 3 VCC = 3.3 V; VIN = 12 V 6 VCC = 5.0 V; VIN = 12 V 6 VCC = VIN = 3.3 V 3 VCC = VIN = 5.0 V 3 VCC = VIN = 12 V 5 TPG-OFF Power Good turn-off time VCC = 3.3 V; VIN = 1.8 V 2.6 µs VCC = 5.0 V; VIN = 1.8 V 3 VCC = 3.3 V; VIN = 12 V 2.56 VCC = 5.0 V; VIN = 12 V 3 VCC = VIN = 3.3 V 2.5 VCC = VIN = 5.0 V 3 VCC = VIN = 12 V 2.5 TSC-OFF Short-circuit delay time VCC = 3.3 V; VIN = 1.8 V 500 ns VCC = 5.0 V; VIN = 1.8 V 500 VCC = 3.3 V; VIN = 12 V 500 VCC = 5.0 V; VIN = 12 V 500 VCC = VIN = 3.3 V 500 VCC = VIN = 5.0 V 500 VCC = VIN = 12 V 500 STEL12H24
6 Application information
6.1 Enable pin
If the VCC is inside its operating range, the STEL12H24 is enabled by driving the EN pin above the VIH threshold. When the VIH threshold is crossed, the internal blocks are turned on and, after TON time, the soft-start procedure to activate the MOSFET starts.
6.2 Undervoltage lockout
The STEL12H24 has two UVLO circuits: one on the VCC pin and another on VIN pin. When the undervoltage lockout threshold VCC-UVLO is crossed (VCC rising), the STEL12H24 enables a timer of 1.2 ms, which activates a discharge circuit for the soft-start cap. This avoids inrush current if the soft-start capacitor remained charged before the VCC-UVLO threshold was crossed. The VIN-UVLO acts on the VIN pin. If the voltage on the VIN pin is below VIN-UVLO threshold, the MOSFET is OFF and the discharge circuit is activated. Both the UVLO circuits are disabled when EN pin is low.
6.3 Quick discharge
The STEL12H24 has an internal discharge switch and resistor connected between BLEED pin and GND which allows discharging the load capacitor when the MOSFET is turned off (please refer to Figure 1). The discharge switch and the MOSFET work always in an opposite manner, when one is ON the other is OFF and vice versa. The BLEED pin must be connected to VOUT through an external series resistor RBLEED. The series resistor minimum value must be calculated in order to limit the power dissipation on the internal Rb below 160 mW and to limit its current to 20 mA maximum. The minimum RBLEED can be calculated using the following formula: RBLEED [kΩ] = VIN / 20 – Rb (min).
6.4 Power Good
The Power Good (PG) pin provides the information about the gate of the MOSFET. It is an open-drain output that goes high when the gate of the MOSFET is fully charged thus giving indication about the operation of the STEL12H24. For whatever reason the MOSFET is turned off (Enable, Thermal protection, UVLO, OVP or short- circuit) the PG pin is pulled low. It is recommended to connect a pull-up resistor greater than 1 kΩ between PG pin and any supply voltage in the system lower than PG pin AMR.
6.5 Short-circuit protection
The STEL12H24 is protected against short-circuit condition at the output. An internal comparator monitors the voltage difference between VIN and BLEED pins. When this voltage exceeds the VSC threshold, the MOSFET is turned off and the discharge switch is activated. The device restarts automatically with a controlled soft-start. The short-circuit trigger point can be reduced by connecting an external resistor between BLEED and VOUT. The leakage current flowing into the BLEED pin increases the voltage drop monitored by the internal comparator thus triggering a lower short-circuit current protection.
6.6 Slew rate control
One of the key features of the STEL12H24 is the controlled ramp-up of the MOSFET current during turn-on. This feature allows to limit the inrush current in hot swap applications. The gate voltage of the MOSFET is increased linearly by mirroring the voltage ramp on the internal soft-start capacitor which provides a default value for the ramp-up time. This time can be increased by connecting a capacitor to CSR pin. The CSR pin is charged with a constant current of KSR so the slew rate is given by the formula: SR E XT = 8 × K SR C SR V s (1) STEL12H24
Application information
DS13821 - Rev 3 page 10/26
Where CSR is the capacitor connected to SR pin. This capacitor should have a minimum nominal value of 100 nF and cannot exceed the value of 1 µF.
6.7 Overvoltage protection
When the input voltage reaches the OVP threshold, the MOSFET is turned off. The STEL12H24 automatically keeps monitoring the VIN voltage and reactivates the MOSFET in a controlled manner when VIN falls below the OVP value. An internal hysteresis avoids oscillations when VIN is close to the OVP value.
6.8 Thermal shutdown
The Thermal protection acts when the junction temperature reaches the TSHDN value. At this point, the MOSFET is shut down and the discharge switch is activated. As soon as the junction temperature falls below the thermal hysteresis value, the device starts again with a soft-start cycle, given that the EN stays high. STEL12H24 DS13821 - Rev 3 page 11/26
7 Typical characteristics
EN = 2 V; CIN = 1 µF; COUT = 10 µF, TJ = 25 °C unless otherwise specified. Figure 7. RON vs. VIN Figure 8. RON vs. temperature Figure 9. Standby current vs. VCC Figure 10. Standby current vs. temperature
8 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.
8.1 DFN12 (3 x 3 mm) package information
Figure 33. DFN12 (3 x 3 mm) package outline
Package information
DS13821 - Rev 3 page 17/26
Table 8. DFN12 (3 x 3 mm) mechanical data Figure 34. DFN12 (3 x 3 mm) recommended footprint DS13821 - Rev 3 page 18/26
8.2 DFN12 (3 x 3 mm) packing information
Figure 35. DFN12 (3 x 3 mm) tape drawing Figure 36. DFN12 (3 x 3 mm) reel oriented DS13821 - Rev 3 page 19/26
Figure 37. DFN12 (3 x 3 mm) reel dimensions DS13821 - Rev 3 page 20/26
9 Ordering information
Table 9. Order codes
Ordering information
DS13821 - Rev 3 page 21/26
Revision history
Table 10. Document revision history 13-Oct-2021 1 Initial release.
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