Diodes Incorporated AP7353D-18CV4-7

Overview

AP7353D-18CV4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 1.8V output, ±1% accuracy, 90dB PSRR at 1kHz, 10µV_rms output noise (10Hz–100kHz), and 18µA typical quiescent current. It features an enable input, built-in discharge function, and operates across 2.0V–5.5V input range - designed for RF power supply rails in compact portable electronics.

For engineers reviewing the AP7353D-18CV4-7 datasheet, AP7353D-18CV4-7 pinout, AP7353D-18CV4-7 application, or AP7353D-18CV4-7 equivalent, key selection criteria include dropout voltage at 250mA (115mV typ. for 1.8V output), thermal resistance (150°C/W), EN logic thresholds (0.4V low / 1.2V high), and compatibility with 1µF ceramic output capacitors.

Technical Context

The AP7353D-18CV4-7 integrates a CMOS-based LDO architecture with internal voltage reference, error amplifier, current-limit circuit, and thermal shutdown. Its discharge function actively pulls the output to ground when disabled, preventing residual voltage hold-up in battery-sensitive systems.

It delivers fast load transient response (<20µs recovery for 1mA→250mA step) and maintains stability with minimal external components: only 1µF input and output ceramic capacitors are required. The device supports operation from –40°C to +85°C ambient and includes short-circuit protection clamping output current to ~350mA.

Key Specifications

Pinout & Package

X1-WLB0707-4 (Type A1) wafer-level chip-scale package (0.64mm × 0.64mm, 0.35mm pitch), 4-bump layout with exposed thermal pad (EP). Optimized for ultra-dense PCBs in space-constrained wearables and hearables.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7353D-18CV4-7, AP7361D-18YG-7 trades size for current headroom and thermal robustness, while XC6210B182MR-G sacrifices PSRR and discharge capability to achieve nanoamp-level standby current - making AP7353D-18CV4-7 the optimal balance for space-constrained, noise-sensitive, and sequenced-power applications.

Availability

AP7353D-18CV4-7 is available at Aetrix Electronics and suitable for smartphone baseband power, Wi-Fi/Bluetooth RF supply, and wearable sensor hub designs requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for AP7353D-18CV4-7 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-performance power management, signal integrity, and connectivity solutions for consumer, industrial, and automotive markets.

The AP7353 series belongs to Diodes' precision LDO portfolio, engineered specifically for noise-critical portable electronics where PSRR, low IQ, and small-footprint packaging are mandatory design constraints.

FAQ

What is the purpose of the exposed pad (EP) on the AP7353D-18CV4-7?

The exposed pad is a thermal interface-not a functional electrical terminal. It must be soldered to a PCB copper pour connected to GND to achieve the specified 150°C/W junction-to-ambient thermal resistance. Leaving it unconnected or using it solely as a GND electrode degrades thermal performance and risks thermal shutdown under 250mA load.

Can the AP7353D-18CV4-7 operate with a 1.5V input voltage?

No. The absolute minimum input voltage is 2.0V per the Recommended Operating Conditions table. At 1.5V input, the device will not regulate and will enter dropout, causing output voltage collapse below 1.8V. For sub-2.0V operation, consider a different LDO family such as Diodes' AP2204K series with 0.8V minimum VIN.

How does the discharge function behave during enable/disable transitions?

When EN is pulled low, the internal 35Ω NMOS switch connects OUT to GND, discharging external capacitance within ~1ms (dependent on C_OUT). When EN returns high, the switch opens and regulation resumes after 180µs typical turn-on time. This prevents back-powering of upstream circuits and ensures deterministic power-down sequencing.

Is a minimum output capacitor required for stability, and what type is recommended?

Yes: minimum effective capacitance is 0.7µF (accounting for temperature, bias, and tolerance derating), with 1µF X7R or X5R ceramic strongly recommended. Capacitors must be placed within 2mm of OUT and GND pins. Tantalum or aluminum electrolytics are not recommended due to ESR and aging effects that compromise stability and transient response.