Diodes Incorporated PT7M8218B18TAEX

Overview

PT7M8218B18TAEX from Pericom Semiconductor is a 300mA, high-PSRR low-dropout linear regulator with 2.8V fixed output, 150mV dropout at 150mA, ±2% initial accuracy, and stable operation with 0.47µF ceramic output capacitors. It serves as a precision power supply for noise-sensitive analog and RF circuitry in portable wireless devices.

For engineers reviewing the PT7M8218B18TAEX datasheet, PT7M8218B18TAEX pinout, PT7M8218B18TAEX application, or PT7M8218B18TAEX equivalent, key selection criteria include PSRR performance at 1kHz, EN pin logic polarity (high-active), thermal shutdown threshold (170°C), and compatibility with low-ESR ceramic capacitors in space-constrained SC70-5L/SOT23-5L footprints.

Technical Context

The PT7M8218B18TAEX integrates a P-channel MOSFET pass element, internal reference voltage source, error amplifier with phase compensation, and protection circuitry including current limit (400mA typical) and thermal shutdown (170°C). Its architecture enables stable regulation with minimal external components.

It operates across 1.7V–5.5V input range and delivers 2.8V output with ±100ppm/°C temperature coefficient and 60µV_RMS output noise (10Hz–100kHz). The EN pin provides high-active control with V_ENH ≥1.2V and V_ENL ≤0.3V thresholds.

Key Specifications

Pinout & Package

PT7M8218B18TAEX is packaged in lead-free, RoHS-compliant SOT23-5L (JEDEC MO-178C/AA) with 0.95mm pitch and 2.82–3.02mm × 1.50–1.70mm footprint. Thermal resistance θ_JA is 250°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P282MR and RT9193-28GB, PT7M8218B18TAEX offers superior PSRR (75dB vs. ≤65dB), integrated auto-discharge, and high-active EN-making it optimal for battery-powered RF and imaging systems requiring precise, sequenced power control.

Availability

PT7M8218B18TAEX is available at Aetrix Electronics and suitable for mobile handset power management, RF front-end biasing, portable imaging modules, and audio codec supply applications requiring stable component supply and long-term lifecycle support.

Supply support for PT7M8218B18TAEX 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-performance interface, timing, and power management ICs for communications and consumer electronics before its 2016 acquisition.

The PT7M8218 belongs to Pericom's ultra-low-noise LDO family designed specifically for noise-critical analog rails in cellular handsets, digital cameras, and portable media devices where PSRR and output accuracy directly impact signal fidelity.

FAQ

What is the minimum input voltage required to maintain 2.8V output at 300mA?

The PT7M8218B18TAEX requires VIN ≥ VOUT + V_DROP, where V_DROP is 150mV at 150mA but increases with load. At 300mA, typical dropout is ~200mV per load regulation curves. Thus, minimum VIN is ~3.0V to sustain full 300mA output at 2.8V, verified by Figure 1 (Vout vs. Iout at Vin=3.5V shows regulation collapse near 300mA).

Can the NC pin (Pin 4) be left floating in production designs?

Yes, Pin 4 is internally unconnected and may be left floating per datasheet guidance. However, tying it to GND improves mechanical reliability during reflow and reduces potential antenna effects in RF-dense layouts-recommended for production-grade designs despite functional equivalence.

Does the PT7M8218B18TAEX support ceramic capacitors smaller than 0.47µF?

No-stability is only guaranteed with ≥0.47µF X5R/X7R ceramic output capacitors, as confirmed by the "Stable with 0.47µF" feature and internal phase compensation design. Using smaller values risks oscillation or degraded transient response, per application note PT0440-1 Section 4.

How does the auto-discharge function behave during fast EN toggling?

When EN transitions from HIGH to LOW, the 50Ω internal discharge path activates immediately, discharging VOUT to <10% in <1ms for a 0.47µF capacitor. During rapid toggling (>10kHz), residual charge may persist due to RC time constant (~23.5µs), but full discharge occurs within 5 time constants (<120µs) per Figure 9 turn-off waveform.