TCR2EF33,LM(CT vs ZXTR2105F-7 Linear Regulators: Component Comparison
Quick verdict
For low-voltage, moderate current applications up to 200mA at 3.3V, the TCR2EF33,LM(CT) offers better quiescent current, lower dropout, and a convenient enable pin, making it a stronger choice for battery-powered or noise-sensitive systems. For automotive-grade or high-voltage input scenarios requiring operation up to 60V and wider temperature ranges, the ZXTR2105F-7 is the preferred option despite its higher quiescent current and lower maximum output current.
Spec comparison table
| Spec | TCR2EF33,LM(CT) | ZXTR2105F-7 | Notes |
|---|---|---|---|
| Control features | Enable | None | Enable pin on TCR2EF33 allows power gating and sequencing flexibility. |
| Quiescent current (Iq) | 60 µA | 800 µA | TCR2EF33’s much lower quiescent current reduces no-load power consumption significantly. |
| Max input voltage | 5.5 V | 60 V | ZXTR2105F-7 supports automotive/high-voltage inputs; TCR2EF33 limited to 5.5V max. |
| Mounting type | Surface Mount | Surface Mount | Both are surface mount devices; package size differs. |
| Number of regulators | 1 | 1 | Equal. |
| Operating temperature | -40°C to 85°C | -65°C to 150°C | ZXTR2105F-7 suitable for extended automotive and industrial temperature ranges. |
| Output configuration | Positive | Positive | Equal. |
| Max output current | 200 mA | 89 mA | TCR2EF33 supports more than twice the current capability. |
| Output type | Fixed | Fixed | Equal. |
| Output voltage range | 3.3 V (fixed) | 5 V (fixed) | TCR2EF33 targets 3.3V logic rails; ZXTR2105F-7 targets 5V systems. |
| Package | SC-74A (SOT-753) | TO-236-3 (SOT-23-3) | ZXTR2105F-7 smaller package but may dissipate less power due to lower max current. |
| Protection features | Over current | None | TCR2EF33 includes overcurrent protection, increasing robustness. |
| PSRR | 73 dB @ 1 kHz | 46 dB @ 100 Hz | TCR2EF33 provides significantly better PSRR, beneficial in noisy environments. |
| Voltage dropout | 0.2 V @ 150 mA | Not specified | TCR2EF33 explicitly specifies low dropout voltage, important for low voltage headroom. |
| Max supply current | Not specified | 6.7 mA | ZXTR2105F-7 supply current is low but quiescent current dominates at 800 µA. |
| Qualification | Not specified | AEC-Q101 | ZXTR2105F-7 is automotive qualified, valuable for safety-critical applications. |
Design trade-offs
The TCR2EF33,LM(CT) shines in low-voltage, low-noise environments where efficiency at light load and minimal dropout voltage are critical. Its 60 µA quiescent current minimizes battery drain in portable devices that spend significant time in standby. The enable pin facilitates power sequencing and firmware control without external components, simplifying system design. The 0.2 V dropout at 150 mA allows the regulator to maintain regulation even when supply voltages are close to the output voltage, increasing usable battery life.
In contrast, the ZXTR2105F-7 targets robust automotive and industrial environments. Its 60 V input rating accommodates higher voltage rails and input transients typical in vehicles, and its wider operating temperature range (-65°C to 150°C) ensures functionality under harsh conditions. The trade-off is a significantly higher quiescent current (800 µA), which may be prohibitive in battery-sensitive designs. Also, the max output current of 89 mA limits its use in applications requiring higher load currents.
From a thermal standpoint, the TCR2EF33’s higher max current leads to higher power dissipation, especially if the input voltage is significantly above 3.3 V. Its slightly larger SC-74A package helps with heat dissipation compared to the ZXTR2105F-7’s smaller SOT-23-3. However, the ZXTR2105F-7’s higher voltage rating and automotive qualification likely come with internal design trade-offs that reduce efficiency and increase quiescent current.
The ZXTR2105F-7 lacks an enable pin, which means it cannot be turned off via logic control without an external pass transistor or MOSFET, complicating power management firmware. The TCR2EF33’s overcurrent protection adds a layer of safety against short circuits or load faults, potentially saving board-level diagnostics and replacement costs.
Cost-wise, the ZXTR2105F-7 may command a premium due to AEC-Q101 qualification and ruggedized design, suitable for automotive supply chains. The TCR2EF33 is likely more cost-effective for consumer or industrial applications without harsh environment requirements.
Use-case fit
Choose TCR2EF33,LM(CT) when:
- Designing battery-powered devices needing low quiescent current and extended standby life.
- Output voltage is 3.3 V with load currents up to 200 mA.
- Power sequencing or enable control is required for system-level power management.
- Noise-sensitive analog or RF circuits require high PSRR to reduce supply ripple.
- Operating environment is moderate temperature range (-40°C to 85°C) without high voltage spikes.
Choose ZXTR2105F-7 when:
- Input voltage can spike up to 60 V, such as in automotive or industrial power rails.
- Operation is required over wide temperature extremes (-65°C to 150°C).
- Output current requirements are below 90 mA.
- Automotive-grade qualification (AEC-Q101) is mandatory for compliance.
- System design can accommodate always-on regulators or external power switches due to lack of enable pin.
Drop-in compatibility
These two parts are not pin-compatible or footprint-compatible. The TCR2EF33 is in an SC-74A (SOT-753) package, whereas the ZXTR2105F-7 uses a smaller SOT-23-3 package. Their different pinouts and package sizes mean swapping one for the other requires PCB redesign. Additionally, the ZXTR2105F-7 lacks an enable pin present on the TCR2EF33, so firmware and control strategies must be adjusted accordingly.
Alternatives to consider
- MIC5205-3.3YM5-TR (Microchip): Low-dropout regulator with 150 mA output, low quiescent current, and enable pin, suitable for low-voltage portable devices.
- LM1117-3.3 (Texas Instruments): Popular 800 mA LDO with adjustable/fixed options, but higher dropout voltage and quiescent current; good for higher current needs.
- TLV70233 (Texas Instruments): Ultra-low quiescent current (~25 µA) 3.3 V LDO, optimized for low power battery applications with a small package.