Diodes Incorporated AP7344D-1818RH4-7

Overview

AP7344D-1818RH4-7 from Diodes Incorporated is a dual-channel, 300mA low-dropout linear regulator with fixed 1.8V outputs per channel, high PSRR (75dB at 1kHz), ultra-low output noise (60µV_rms), and ±1% output voltage accuracy over temperature. Built on a CMOS process, it integrates independent enable inputs and current-limit protection, and is optimized for RF supply rails and noise-sensitive analog subsystems in portable electronics.

For engineers reviewing the AP7344D-1818RH4-7 datasheet, AP7344D-1818RH4-7 pinout, AP7344D-1818RH4-7 application, or AP7344D-1818RH4-7 equivalent, key selection criteria include dual-channel independent enable control, 1.7V–5.25V input range, thermal-pad-enabled X2-DFN1612-8 package, and discharge-capable output architecture (D-suffix).

Technical Context

The AP7344D-1818RH4-7 implements two fully independent LDO regulators sharing only GND and thermal pad connections. Each channel features a precision voltage reference, error amplifier, current-limit circuit, and CMOS pass transistor with <0.30V dropout at 300mA (for V_OUT = 1.8V). The D-suffix denotes integrated auto-discharge functionality via 50Ω N-channel FETs on both outputs when disabled.

Its design supports simultaneous regulation of two critical low-noise rails-e.g., RF transceiver core and I/O supplies-with separate EN1/EN2 control enabling staggered power-up, dynamic rail sequencing, and independent shutdown to minimize system standby current (1.0µA typical ISTANDBY).

Key Specifications

Pinout & Package

X2-DFN1612-8 (1.6mm × 1.2mm, 0.4mm pitch) with exposed thermal pad; requires PCB copper pour connected to GND for thermal dissipation (θ_JA ≈ 190°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7344D-1818RH4-7, the AP7345D offers measurable PSRR and IQ improvements with full drop-in compatibility, while the TPL7407LDR sacrifices integration and control flexibility to meet basic single-rail needs at lower unit cost.

Availability

AP7344D-1818RH4-7 is available at Aetrix Electronics and suitable for smartphone baseband power, RF transceiver supply, camera ISP core supply, and portable media player audio codec applications requiring stable component supply, long-term obsolescence management, and RoHS-compliant packaging.

Supply support for AP7344D-1818RH4-7 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 power management, signal integrity, and protection solutions for consumer, industrial, and communications markets.

The AP7344 series belongs to Diodes' high-PSRR, low-noise LDO portfolio designed specifically for noise-critical portable electronics where dual-rail sequencing, compact footprint, and battery efficiency are paramount.

FAQ

Is AP7344D-1818RH4-7 pin-compatible with AP7344-1818RH4-7?

No. The "D" suffix indicates integrated auto-discharge FETs on both outputs, while the non-D version lacks discharge capability. Pin assignments and package are identical, but discharge functionality alters the VOUT behavior during shutdown-requiring layout verification if substituting between versions.

What is the maximum allowable input voltage for continuous operation?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V risks exceeding power dissipation limits and degrading long-term reliability-even if within absolute maximum ratings-due to increased thermal stress on the CMOS pass elements.

Can EN1 and EN2 be tied together and driven by a single GPIO?

Yes. EN1 and EN2 are CMOS inputs with negligible leakage (<1.0µA), so they can be paralleled and driven by one microcontroller pin. This simplifies control logic but eliminates independent rail sequencing-use only when simultaneous enable/disable is acceptable for the target application.

Does the thermal pad require an electrical connection to GND?

No. The thermal pad is not an electrical terminal. It must be soldered to a PCB copper pour for thermal conduction, and connecting that pour to GND improves EMI performance-but the pad itself has no GND function. Using it solely as a GND electrode without thermal design compromises junction temperature and reliability.