Toshiba Introduces TCKE5 eFuse ICs for 1.8 V Power-Line Protection

Toshiba has introduced the TCKE5 series of electronic fuse (eFuse) ICs, extending its power-line protection range to 1.8 V supplies in consumer electronics and computing devices.

The four devices combine overcurrent and short-circuit protection in a compact package, supporting 1.8 V, 3.3 V and 5 V power lines. Applications include SD memory cards, USB and HDMI devices, laptop PCs and gaming consoles, where board space is limited and protection must operate at low supply voltages.

The series comprises the TCKE501UA, TCKE501UL, TCKE502UA and TCKE502UL, with different recovery and slew-rate options to suit the requirements of the downstream circuit.

Adjustable Overcurrent and Short-Circuit Protection

An external resistor sets the overcurrent detection threshold, allowing designers to match protection to the requirements of the downstream circuit. A typical mask time of 2.4 ms allows brief current peaks to pass without triggering overcurrent shutdown. If the overcurrent persists beyond this period, the IC switches off its output.

A separate short-circuit protection function responds to higher fault currents. The TCKE5 series also provides two slew-rate options with different output-voltage rise times to accommodate power-sequencing requirements. Slew-rate control limits the current drawn when charging the output capacitor at switch-on.

Automatic Retry or Latched Shutdown

The four devices offer two recovery methods following a fault. The TCKE501UA and TCKE502UA provide automatic retry, while the TCKE501UL and TCKE502UL latch off and require an external signal to restart. This gives designers a choice of recovery behavior depending on how the protected circuit needs to respond to an abnormal condition.

All four devices support a continuous output current of up to 1 A and are housed in Toshiba's SOT-353F (UFV) package, measuring 2.0 × 2.1 × 0.7 mm.

For operation at input voltages between 5 V and 5.5 V, Toshiba specifies additional precautions involving output capacitance or an external Schottky barrier diode to address voltage transients during short-circuit protection. Operation should be verified in the intended system.

Shipments of the TCKE5 series have started.

Learn more and read the original announcement at toshiba.semicon-storage.com.

Technology Overview

The Toshiba TCKE5 series comprises four electronic fuse ICs for 1.8 V, 3.3 V and 5 V power-line protection. Operating from 1.7 V to 5.5 V, the devices combine adjustable overcurrent detection, a typical 2.4 ms mask time and separate short-circuit protection. The series supports up to 1 A continuous output current, with automatic-retry and latch-off options and two slew-rate configurations. All four devices use a 2.0 × 2.1 × 0.7 mm SOT-353F package.

FAQs

What power lines does the Toshiba TCKE5 series support?

The devices operate from 1.7 V to 5.5 V and are designed to protect 1.8 V, 3.3 V and 5 V supplies in consumer electronics and computing devices.

How does the TCKE5 series handle overcurrent conditions?

An external resistor sets the detection threshold. A typical 2.4 ms mask time allows brief current peaks before the IC shuts down its output if the overcurrent persists. Separate short-circuit protection handles higher fault currents.

What is the difference between the TCKE501 and TCKE502 variants?

The TCKE501 and TCKE502 groups offer different output slew rates. Within each group, the UA version provides automatic fault recovery, while the UL version uses latched shutdown requiring an external restart signal.