Diodes Incorporated AP7343D-185W5-7

Overview

AP7343D-185W5-7 from Diodes Incorporated is a 300mA low-dropout linear regulator with fixed 1.85V output, ±1% accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Packaged in SOT25, it features enable control, thermal shutdown, and short-circuit protection-designed for RF supply rails in portable wireless communication devices.

For engineers reviewing the AP7343D-185W5-7 datasheet, AP7343D-185W5-7 pinout, AP7343D-185W5-7 application, or AP7343D-185W5-7 equivalent, key selection criteria include dropout voltage at 300mA (≤0.39V), quiescent current (35–60µA), EN input thresholds (0–0.5V low / ≥1.3V high), and thermal resistance (179°C/W J-A in SOT25).

Technical Context

The AP7343D-185W5-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, current limit, and thermal shutdown circuitry. Its enable input directly controls NMOS pass transistor gate bias, enabling fast turn-on/turn-off transitions with load-step response under 100µs.

It delivers stable 1.85V output across –40°C to +85°C ambient, with line regulation ≤0.1%/V and load regulation ≤30mV from 1mA to 300mA. The device includes auto-discharge functionality (enabled by 'D' suffix) via an internal 30Ω N-channel switch between VOUT and GND during shutdown.

Key Specifications

Pinout & Package

SOT25 package (3.0mm × 1.7mm × 1.3mm height) with exposed pad for thermal enhancement; recommended PCB layout uses large copper area connected to GND under EP.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-1852E/MB and XC6210B185MR-G, the AP7343D-185W5-7 uniquely combines ±1% accuracy, 75dB PSRR, 60µV_rms noise, and integrated discharge-making it optimal for space-constrained RF and imaging systems demanding both precision and fast power sequencing.

Availability

AP7343D-185W5-7 is available at Aetrix Electronics and suitable for RF transceiver power, camera ISP biasing, portable media player audio codecs, and wireless headset baseband applications requiring stable component supply, automotive-grade traceability, and long-term lifecycle support.

Supply support for AP7343D-185W5-7 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and connectivity applications.

The AP7343 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for low-noise, low-power portable electronics-including smartphones, tablets, and wireless infrastructure equipment.

FAQ

What is the minimum input voltage required for AP7343D-185W5-7 to regulate 1.85V at 300mA?

The minimum input voltage is determined by dropout: at 300mA and +25°C, max dropout is 0.39V in SOT25. Thus, VIN must be ≥ 1.85V + 0.39V = 2.24V. At –40°C or +85°C, dropout increases slightly-designers should allow ≥2.3V nominal input for full-temperature-margin operation.

Does AP7343D-185W5-7 require an external pull-up resistor on the EN pin?

No external pull-up is required. When unused, EN must be tied directly to VIN to ensure reliable turn-on; the internal logic accepts VIN as valid high-level input. Adding a pull-up risks violating absolute maximum EN voltage (6.0V) if VIN exceeds that limit, and introduces unnecessary leakage paths.

Can AP7343D-185W5-7 be used with ceramic output capacitors smaller than 1µF?

Yes-the AP7343D-185W5-7 is stable with ≥0.47µF ceramic output capacitors. However, for loads with >100mA step changes, ≥1µF is recommended to maintain ≤1.85V ±30mV regulation and minimize undershoot/overshoot per load transient waveforms in the datasheet.

How does the auto-discharge feature affect PCB layout or system timing?

The 30Ω internal discharge FET pulls VOUT to GND within ~100µs after EN goes low. Layout requires no special routing-but designers must ensure downstream circuits tolerate this rapid discharge (e.g., avoid connecting to open-drain buses or unpowered logic inputs). It eliminates need for external bleed resistors, saving board space and BOM cost.