TCKE502UL - 1A eFuse IC, 75mΩ, SOT-353F | Toshiba
MPN: TCKE502UL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.5 | $5.00 |
| 100 | $0.38 | $38.00 |
| 500 | $0.31 | $155.00 |
| 1,000 | $0.26 | $260.00 |
TCKE502UL Overview
An eFuse IC is a reusable, resettable electronic circuit-protection device that replaces disposable fuses and discrete protection circuits in a power path. Positioned within the power management IC hierarchy (eFuse IC -> hot-swap protection IC -> voltage regulator family -> power management IC), it combines a power MOSFET switch with protection logic: when an overcurrent, short-circuit, or over-temperature event occurs, the device rapidly turns off the power path and can later be reset, protecting downstream loads such as SoCs, sensors, and wireless modules.
Key features of the TCKE502UL include adjustable overcurrent protection set by a single external resistor, fast short-circuit protection, thermal shutdown, and a low 75 mΩ on-resistance that minimizes voltage drop and power loss at the full 1A load. The 1.7V minimum input makes it suitable for modern 1.8V rails, and the SOT-353F package occupies minimal board area for space-constrained designs.
The TCKE5 Series is Toshiba's low-voltage eFuse family; the lineup comprises four products, TCKE501UA, TCKE501UL, TCKE502UA, and TCKE502UL, all housed in the SOT-353F (UFV) package, with suffix distinctions covering latch-type versus auto-retry behavior between the 501 and 502 variants. The low-voltage capability addresses the growing use of 1.8V power lines driven by miniaturization and lower power consumption in IoT and consumer equipment.
Typical applications include IoT equipment power rails, consumer equipment, general-purpose power supplies, USB accessory ports, battery-powered portable devices, and post-regulator protection after DC-DC converters on 1.8V to 5V rails.
When designing with this device, size the external ILIM resistor for the desired overcurrent threshold with margin above the maximum load current, and verify the thermal rise across the 75 mΩ on-resistance at continuous full load.
This page synthesizes distributor availability data, same-series drop-in options, and practical design notes not found in the manufacturer datasheet. Pricing references are as of 2026-10-19.
Drop-in alternatives for TCKE502UL — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TCKE502UL (same form factor and footprint) — differing in Applications, Overcurrent Protection, Package, On-Resistance, Short-Circuit Protection.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TCKE501UL
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →TCKE502UA
✅ Drop-In✓ In Stock
$0.28 / Unit
View Datasheet →TCKE501UA
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$0.23 / Unit
View Datasheet →TCKE502UL Specifications
| Product Type | eFuse IC (electronic fuse) |
| Input Voltage Range | 1.7 V to 5.5 V |
| Recommended Operating Input Voltage | 1.8 V to 5.0 V |
| Maximum Output Current | 1.0 A |
| On-Resistance | 75 mΩ (typical) |
| Overcurrent Protection | Adjustable via external resistor (ILIM) |
| Short-Circuit Protection | Yes |
| Thermal Shutdown | Yes (overheat protection) |
| Topology | High-side switch |
| Package | SOT-353F (UFV) |
| Mounting Type | Surface Mount |
| Number of Inputs / Outputs | Single-input, single-output |
| Applications | Consumer equipment / IoT equipment / General purpose power supply |
| Series | TCKE5 Series |
| Reusable Fuse Function | Yes (resettable) |
TCKE502UL Pin Configuration
| Pin 1 | VIN — Input supply voltage (1.7 V to 5.5 V) |
| Pin 2 | GND — Ground |
| Pin 3 | EN — Enable/control input for on-off and fault reset |
| Pin 4 | ILIM — Overcurrent threshold setting via external resistor |
| Pin 5 | VOUT — Protected output to load |
Typical Applications
TCKE502UL is suitable for 6 applications: IoT Equipment Power Protection, Consumer Equipment Power Rails, General-Purpose Power Supply Output Protection, Battery-Powered Portable Devices, 1.8V Low-Voltage Logic Rail Protection, USB and Accessory Port Protection.
IoT Equipment Power Protection
IoT devices increasingly run on 1.8V power lines driven by miniaturization and lower power consumption, and the TCKE502UL was designed specifically for this environment with its 1.7V minimum input and 1.0A output. Placed in series with the 1.8V or 3.3V rail feeding a wireless module or microcontroller, the 75 mΩ on-resistance drops only about 75 mV at full load, preserving rail accuracy for low-voltage SoCs. Its adjustable overcurrent threshold via one external ILIM resistor lets designers set protection just above the radio's burst current, while short-circuit and thermal protection guard against board-level faults. Because the eFuse acts as a reusable fuse, field fault events do not require service replacement as a one-time fuse would.
Recommended
Consumer Equipment Power Rails
Consumer electronics such as set-top boxes, accessories, and smart-home devices require compact, low-cost circuit protection that does not complicate the bill of materials. The TCKE502UL integrates the protection function in a single 5-pin SOT-353F (UFV) package, replacing a discrete fuse, sense resistor, and comparator chain. Its 1.7V to 5.5V input range covers the 3.3V and 5V rails typical of consumer products, while the 75 mΩ on-resistance keeps efficiency loss at 1A to roughly 75 mW, important for thermally sealed enclosures. The latch-style overcurrent response of the 502 variant keeps a faulted rail off until the system controller intervenes, preventing repeated fault cycling in consumer products with no user-serviceable parts.
Recommended
General-Purpose Power Supply Output Protection
In general-purpose power supplies and DC-DC converter outputs, the TCKE502UL serves as a hot-swap style series protector between the converter and the load. Rated for 1.8V to 5.0V operation at up to 1.0A, it complements a buck converter by adding fault isolation the converter itself may lack: short-circuit protection reacts far faster than a converter's cycle-by-cycle limit, and thermal shutdown protects the pass path during sustained overloads. The adjustable overcurrent threshold set by the external ILIM resistor allows one PCB design to serve multiple output-current variants. The low 75 mΩ on-resistance maintains load regulation accuracy because the drop at full current is only about 75 mV on a 5V rail.
Recommended
Battery-Powered Portable Devices
Portable and wearable devices benefit from the TCKE502UL's combination of small SOT-353F footprint, low 1.7V operating floor, and low 75 mΩ conduction loss, all of which preserve battery runtime and board space. Placed between the battery/boost output and the load switch feeding the application processor, it isolates faults such as a damaged flex cable or shorted peripheral without sacrificing a one-time fuse. The latch-off behavior of the 502 variant is valuable here because repeated auto-retry into a hard short would drain the battery; instead the system controller can count fault events and shut down gracefully. Quiescent consumption of the protection path remains negligible relative to typical wearable sleep currents.
Recommended
1.8V Low-Voltage Logic Rail Protection
The defining feature of the TCKE5 Series is 1.7V low-voltage operation, announced by Toshiba in October 2026 specifically to address the spread of 1.8V power lines in modern electronics. Many legacy eFuse ICs require 2.5V or higher inputs and cannot supervise a 1.8V rail; the TCKE502UL can, protecting LPDDR memory supplies, low-voltage FPGA banks, and 1.8V sensor interfaces. At 1A, the 75 mΩ internal MOSFET drops about 75 mV, leaving workable margin on a rail that may only tolerate 5% deviation. Designers should set the ILIM threshold above the rail's inrush plus steady-state current, and verify total drop against the load's minimum operating voltage as estimated from the load datasheet.
Recommended
USB and Accessory Port Protection
Accessory ports exposed to user connection events are prone to short circuits and overcurrent faults, making them a classic eFuse application. The TCKE502UL protects a 5V accessory output up to 1.0A within its 5.5V maximum input, with short-circuit protection reacting quickly to a direct short on the connector and thermal shutdown covering sustained overloads. The adjustable ILIM threshold lets the same design serve both 500 mA and higher-current port variants by changing one resistor. The latch-style response prevents the port from oscillating on and off into a faulted cable, and the reusable-fuse nature means a resolved fault is cleared simply by cycling the enable or input power, with no consumable fuse to replace.
Recommended
Recommended Products Summary
Engineering reference data for TCKE502UL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TCKE501UL | TCKE502UA | TCKE501UA |
|---|---|---|---|---|
| Package | SOT-353F (UFV) | SOT-353F (UFV) - same | SOT-353F (UFV) - same | SOT-353F (UFV) - same |
| Brand | Toshiba | Toshiba | Toshiba | Toshiba |
| Input Voltage Range | 1.7 V to 5.5 V | 1.7 V to 5.5 V | 1.7 V to 5.5 V | 1.7 V to 5.5 V |
| Output Current | 1.0 A | 1.0 A | 1.0 A | 1.0 A |
| On-Resistance | 75 mΩ (typ) | 75 mΩ (typ) | 75 mΩ (typ) | 75 mΩ (typ) |
| Overcurrent Protection | Adjustable (external ILIM resistor) | Adjustable (external ILIM resistor) | Adjustable (external ILIM resistor) | Adjustable (external ILIM resistor) |
| Fault Response Style | Latch-off style (502 variant) | Auto-retry style (501 variant) | Latch-off style (502 variant) | Auto-retry style (501 variant) |
| Protection Functions | OCP + short-circuit + thermal shutdown | OCP + short-circuit + thermal shutdown | OCP + short-circuit + thermal shutdown | OCP + short-circuit + thermal shutdown |
Key Differentiators
- True 1.7V low-voltage operation for 1.8V rails (vs TCKE8xx series (18 V, 5 A eFuse))
- Smallest package in the Toshiba eFuse lineup (vs TCKE502UA)
- Latch-off fault response protects battery capacity (vs TCKE501UL)
Design Notes
Estimated: at VIN = 5V and full 1A load, conduction loss in the TCKE502UL is I^2 x R = 1^2 x 0.075 ohm = 75 mW, and the drop across the switch is 75 mV. On a 1.8V rail this 75 mV drop consumes about 4% of the rail budget, so verify the load's minimum operating voltage before committing. Set the ILIM resistor so the overcurrent trip point sits 20-50% above the worst-case steady-state load current including inrush, while remaining low enough to protect the upstream source.
Place a ceramic input capacitor (for example 1 uF, value to be confirmed against the Toshiba TCKE5 Series datasheet typical application) close to the VIN pin and an output capacitor at VOUT to support the load during transient faults and to damp inrush at turn-on. Keep the VIN-to-VOUT current path short and wide, with the GND pin returned directly to the system ground. The SOT-353F package is thermally compact, so adequate copper area on all five pins aids heat spreading at continuous full-load operation.
Do not exceed the 5.5V absolute maximum input; 5V-rail designs with unregulated adapters or hot-plug transients should include input TVS clamping. Confirm the fault-response style before layout signoff: the 502 (latch) variants stay off after an overcurrent event until the enable or input is cycled, while the 501 (auto-retry) variants periodically retest the fault, which may be undesirable on battery-powered designs. Also verify the correct suffix for reel versus cut-tape ordering (TCKE502UL,LF(CT) is the cut-tape option at DigiKey).
Compliance Information
Compliance statuses were not stated in the provided web data; the ,LF suffix indicates lead forming/packaging variant per Toshiba convention. Confirm RoHS/REACH status on the official Toshiba product page before procurement.
