Diodes Incorporated AP7353D-45CV4-7

Overview

AP7353D-45CV4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 4.5V output, ±1% accuracy, 90dB PSRR at 1kHz, 10µV_rms output noise (10Hz–100kHz), and 18µA typical quiescent current. It features enable control, thermal shutdown, short-circuit protection, and integrated auto-discharge functionality - designed for RF supply rails and noise-sensitive analog circuits in portable electronics.

For engineers reviewing the AP7353D-45CV4-7 datasheet, AP7353D-45CV4-7 pinout, AP7353D-45CV4-7 application, or AP7353D-45CV4-7 equivalent, key selection criteria include dropout voltage at 250mA (55mV typ. @ V_OUT=4.5V), EN logic thresholds (0.4V low / 1.2V high), thermal resistance (150°C/W), and compatibility with 1µF ceramic output capacitors.

Technical Context

The AP7353D-45CV4-7 implements a CMOS-based LDO architecture with an internal voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor. Its auto-discharge function activates an internal 35Ω pull-down path from OUT to GND when EN is low, ensuring rapid output discharge during shutdown.

This regulator operates across 2.0V–5.5V input range and maintains regulation down to 55mV dropout at 250mA load for 4.5V output. It delivers fast load transient response (<20µs settling time) and stable operation with 1µF X7R/X5R ceramic capacitors on both IN and OUT pins.

Key Specifications

Pinout & Package

AP7353D-45CV4-7 uses the X1-WLB0707-4 (Type A1) wafer-level chip-scale package (0.64mm × 0.64mm, 0.35mm pitch), featuring four solder bumps and an exposed thermal pad (EP) for enhanced heat dissipation. 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-4502E/MB and XC6210B452MR-G, AP7353D-45CV4-7 uniquely combines 90dB PSRR, 10µV_rms noise, and integrated 35Ω discharge - making it optimal for RF and audio subsystems where noise, transient fidelity, and controlled shutdown are co-dependent requirements.

Availability

AP7353D-45CV4-7 is available at Aetrix Electronics and suitable for smartphone RF supplies, wearable sensor hubs, and portable camera ISPs requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AP7353D-45CV4-7 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 devices, with design centers across Asia, Europe, and the US, serving industrial, computing, consumer, and communications markets.

The AP7353 series targets portable and battery-powered applications demanding high PSRR, low noise, and ultra-low quiescent current - specifically engineered for RF, imaging, and audio subsystems in space-constrained, energy-sensitive designs.

FAQ

What is the minimum input voltage required for AP7353D-45CV4-7 to regulate 4.5V output at 250mA?

The minimum input voltage is determined by dropout: 55mV (typical) + 4.5V = 4.555V. Per datasheet specifications, VIN must be ≥4.555V to sustain full 250mA load at 4.5V output. At lower VIN, output drops proportionally - e.g., at VIN=4.5V, maximum sustainable load is ~150mA based on 110mV max dropout at 4.5V output.

Can AP7353D-45CV4-7 operate without an output capacitor?

No. The AP7353D-45CV4-7 requires a minimum 0.7µF ceramic output capacitor (X7R/X5R) for stability, with 1µF recommended. Omitting C_OUT causes oscillation and unregulated output due to phase margin loss in the internal control loop - confirmed by stability testing in DS41656 Rev. 4-2 Section 11.

How does the auto-discharge function behave during EN deactivation?

When EN is pulled low, the internal 35Ω NMOS switch connects OUT to GND, discharging attached capacitance. For a 1µF output cap, discharge time to 10% V_OUT is ~35µs (τ = R×C). This path remains active until V_OUT falls below ~0.5V, preventing residual voltage from interfering with downstream logic reset sequences.

Is AP7353D-45CV4-7 qualified for automotive applications?

No. AP7353D-45CV4-7 is not AEC-Q100 qualified. Diodes Incorporated explicitly states that automotive-grade versions require specific change control, PPAP capability, and IATF 16949 manufacturing - none of which apply to this part. Use only in commercial/industrial temperature grade (-40°C to +85°C ambient) applications.