Diodes Incorporated AP7340-18FS4-7

Overview

AP7340-18FS4-7 from Diodes Incorporated is a 1.8V fixed-output, 150mA low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, 60µV_RMS output noise (10Hz–100kHz), and 35µA quiescent current. It features CMOS-based architecture, enable control, and is optimized for RF supply and portable media applications requiring stable, low-noise biasing.

For engineers reviewing the AP7340-18FS4-7 datasheet, AP7340-18FS4-7 pinout, AP7340-18FS4-7 application, or AP7340-18FS4-7 equivalent, key selection criteria include dropout voltage (0.34V @150mA for 1.8V output), thermal performance in X2-DFN1010-4, EN logic thresholds (0.5V_IL/1.3V_IH), and compatibility with 0.47µF ceramic input/output capacitors.

Technical Context

The AP7340-18FS4-7 integrates a precision voltage reference, error amplifier, and current-limit circuit in a CMOS process to deliver high PSRR and low noise. Its internal resistor network fixes V_OUT at 1.8V, eliminating external feedback components.

Enable functionality is implemented via a dedicated EN pin with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V) and sub-1µA leakage; shutdown draws only 0.01µA typical standby current. Short-circuit protection limits fold-back current to 55mA when V_OUT is shorted to GND.

Key Specifications

Pinout & Package

The AP7340-18FS4-7 is housed in a 1.0mm × 1.0mm X2-DFN1010-4 package with exposed thermal pad, enabling ultra-compact PCB layouts and efficient heat dissipation in space-constrained handheld designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6206P182MR-G, the AP7340-18FS4-7 uniquely balances 150mA drive capability, 75dB PSRR, and 1.0mm² footprint-making it the only option qualified for compact, high-performance RF and imaging subsystems demanding simultaneous low noise, high current, and minimal area.

Availability

AP7340-18FS4-7 is available at Aetrix Electronics and suitable for smartphone baseband power, RF transceiver bias, camera sensor core supply, and portable media player audio codec applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7340-18FS4-7 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-reliability power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.

The AP7340 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive portable electronics where compact size, battery efficiency, and RF immunity are critical design constraints.

FAQ

What is the minimum input voltage required for AP7340-18FS4-7 to maintain regulation at full 150mA load?

The AP7340-18FS4-7 requires a minimum input voltage of 2.14V to sustain 1.8V output at 150mA, based on its typical 0.34V dropout voltage. At ambient temperatures up to +85°C, the maximum dropout rises to 0.42V, so 2.22V input is recommended for guaranteed operation across full temperature range.

Can the EN pin be left unconnected, or does it require a pull-up/down resistor?

The EN pin must never be left floating. It must be driven actively high (≥1.3V) to enable regulation or low (≤0.5V) to disable it. If unused, tie EN directly to VIN to ensure permanent enable; no external resistor is needed due to internal biasing, and floating EN risks erratic enable/disable behavior.

Is AP7340-18FS4-7 compatible with ceramic output capacitors smaller than 0.47µF?

No-Diodes specifies 0.47µF as the minimum ceramic output capacitance for stability and transient response. Using smaller values may cause oscillation or excessive overshoot during load steps; the device is not characterized for stable operation below this value per DS35282 Rev. 5–2.

Does AP7340-18FS4-7 include reverse-voltage or reverse-current protection?

No-the AP7340-18FS4-7 lacks integrated reverse-voltage or reverse-current protection. If the output voltage exceeds the input (e.g., during hot-swap or backup battery scenarios), current can flow backward through the pass transistor, potentially damaging upstream circuitry unless external protection diodes or MOSFETs are added.