Toshiba Semiconductor and Storage TCR3UM09A,LF

Overview

TCR3UM09A,LF from Toshiba Electronic Devices & Storage Corporation is a CMOS low-dropout linear regulator delivering fixed 0.9 V output at up to 300 mA, featuring ultra-low quiescent current (0.34 μA typ.), fast load transient response (±51/36 mV), and thermal shutdown protection. It operates from 1.5–5.5 V input and targets power-sensitive portable systems such as wearable sensors and IoT edge nodes.

For engineers reviewing the TCR3UM09A,LF datasheet, TCR3UM09A,LF pinout, TCR3UM09A,LF application, or TCR3UM09A,LF equivalent, key selection criteria include dropout voltage at 300 mA (933 mV typ. for 0.9 V output), ±1.0% output accuracy (≥1.8 V), auto-discharge capability, ceramic capacitor compatibility (1 μF min), and DFN4E package footprint constraints.

Technical Context

The TCR3UM09A,LF integrates a PMOS pass transistor with internal current limiting, thermal shutdown circuitry triggered at 158°C, and an on/off control input with pull-down logic. Its feedback loop is optimized for stability with 1 μF ceramic capacitors on both input and output.

It implements auto-discharge via a 7 Ω internal discharge switch between VOUT and GND when CONTROL is low, and includes inrush current protection plus overcurrent protection that limits output to 545 mA (typ.) before foldback activation.

Key Specifications

Pinout & Package

TCR3UM09A,LF is housed in a 1.0 mm × 1.0 mm × 0.60 mm max DFN4E plastic mold package with wettable flank terminals and a center thermal pad connected to GND. The package weighs 1.3 mg and supports high-density mounting on space-constrained PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with R1114N091B-TR-FE and MCP1700T-0902E/TT, the TCR3UM09A,LF delivers 300 mA output, 0.34 μA quiescent current, and integrated auto-discharge - making it uniquely suited for compact, battery-constrained systems requiring full enable control and rapid power-state transitions.

Availability

TCR3UM09A,LF is available at Aetrix Electronics and suitable for wearable health sensors, IoT edge nodes, low-voltage RF modules, and portable medical diagnostics requiring stable component supply and long-term manufacturability.

Supply support for TCR3UM09A,LF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Toshiba Electronic Devices & Storage Corporation designs high-efficiency, miniaturized semiconductor solutions for consumer, industrial, and automotive markets, with emphasis on reliability and power optimization.

The TCR3UM series was developed specifically for ultra-low-power portable electronics, delivering high-performance LDO regulation in the smallest possible footprint without compromising thermal safety or transient behavior.

FAQ

What is the maximum input voltage rating for the TCR3UM09A,LF?

The TCR3UM09A,LF has an absolute maximum input voltage of 6.0 V. However, its recommended operating input range is 1.5 V to 5.5 V per the datasheet's Operating Ranges table. Exceeding 5.5 V may trigger overvoltage stress even if within absolute maximum ratings, so system design should maintain VIN ≤ 5.5 V for reliable long-term operation. The TCR3UM09A,LF uses internal protection circuits but is not rated for continuous operation above this limit.

Does the TCR3UM09A,LF require external components for stable operation?

Yes - the TCR3UM09A,LF requires minimum 1.0 μF ceramic capacitors on both VIN and VOUT pins, placed as close as possible to the device. These capacitors ensure loop stability, suppress input ripple, and support fast transient response. The datasheet confirms compatibility with standard X5R/X7R dielectrics and specifies ESR < 10 Ω. No additional compensation network or ferrite beads are needed for basic operation, but layout adherence (short traces, solid GND plane) is critical for the TCR3UM09A,LF to meet published specs.

How does the auto-discharge function work in the TCR3UM09A,LF?

When the CONTROL pin is driven LOW (≤0.4 V), the TCR3UM09A,LF disables regulation and activates an internal 7 Ω discharge switch between VOUT and GND. This rapidly drains residual charge from the output capacitor, pulling VOUT to near-zero volts within microseconds. This prevents back-powering of upstream circuitry or unintended biasing of downstream components - a critical feature for power-gated subsystems in wearables and IoT devices. The TCR3UM09A,LF implements this without external MOSFETs or resistors.

Can the TCR3UM09A,LF be used with lithium coin-cell batteries?

Yes - the TCR3UM09A,LF is well-suited for lithium coin-cell (e.g., CR2032) applications due to its 1.5 V minimum input voltage, 0.34 μA quiescent current, and ability to deliver 300 mA peak current. With typical coin-cell capacity (~225 mAh) and average load currents under 10 μA, the TCR3UM09A,LF enables multi-year operation in always-on sensing nodes. Its low dropout (933 mV typ. at 300 mA) allows usable runtime down to ~2.4 V cell voltage, extending effective battery life beyond competing regulators with higher IQ or dropout.

What thermal considerations apply to the TCR3UM09A,LF in high-current operation?

The TCR3UM09A,LF features thermal shutdown at 158°C with 28°C hysteresis, but its safe continuous operation depends on PCB thermal design. At 300 mA and 3.3 V input → 0.9 V output, power dissipation is ~720 mW - exceeding the 420 mW board-mounted rating unless thermal relief is implemented. Engineers must solder the center GND pad to a ≥20 mm² copper pour, use ≥4 thermal vias, and avoid enclosing the TCR3UM09A,LF under shields. Derating is required above 60°C ambient per the Power Dissipation graph on page 7 of the datasheet.