Diodes Incorporated AP7343-12FS4-7B

Overview

AP7343-12FS4-7B from Diodes Incorporated is a 300mA, 1.2V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Built on a CMOS process, it features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails in compact portable electronics.

For engineers reviewing the AP7343-12FS4-7B datasheet, AP7343-12FS4-7B pinout, AP7343-12FS4-7B application, or AP7343-12FS4-7B equivalent, key selection criteria include its 1.7V–5.25V input range, ultra-low 35µA quiescent current, X2-DFN1010-4 (Type B) package footprint, and guaranteed 300mA output under tight thermal constraints.

Technical Context

The AP7343-12FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and CMOS pass transistor-enabling stable 1.2V regulation with dropout as low as 0.46V at 300mA. Its enable input (EN) provides precise on/off control with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and internal thermal shutdown activates at +150°C with +20°C hysteresis.

Designed for high-PSRR, low-noise operation, it achieves 75dB ripple rejection at 1kHz and maintains stability with only 1µF ceramic output capacitance. The device supports fast load transient response (e.g., 1mA ↔ 300mA steps) and exhibits <±30ppm/°C output voltage temperature coefficient across –40°C to +85°C ambient.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - requires PCB copper area connected to GND for optimal thermal performance (R_θJA = 237°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1202E/TO and XC6210B122MR-G, the AP7343-12FS4-7B delivers superior noise/PSRR performance in the smallest footprint while integrating essential system-level features-enable control, thermal shutdown, and short-circuit protection-without increasing bill-of-materials count.

Availability

AP7343-12FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, mobile baseband core supplies, camera sensor analog rails, and wireless adapter PHY supplies requiring stable component supply and long-term production continuity.

Supply support for AP7343-12FS4-7B 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 manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The AP7343 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for low-power, noise-sensitive portable electronics where small size, high PSRR, and ultra-low quiescent current are mandatory.

FAQ

What is the maximum allowable input voltage for AP7343-12FS4-7B?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V risks violating safe operating area limits and may trigger thermal shutdown or degrade long-term reliability-even if within absolute maximum ratings.

Does AP7343-12FS4-7B include an output discharge function?

No-the "7B" suffix and absence of "D" in the part number indicate the non-discharge variant. When disabled via EN, the output remains floating; an external pull-down resistor is required if rapid VOUT discharge is needed for system safety or sequencing.

Can AP7343-12FS4-7B operate with only 0.47µF input capacitance?

Yes-a minimum 0.47µF ceramic capacitor is specified between VIN and GND. However, for loads with fast transients (e.g., burst-mode RF transmission), a 1µF or larger input capacitor improves stability and reduces input voltage droop during high di/dt events.

How does the exposed pad (EP) affect thermal performance?

The EP is a thermal-only pad-not electrically connected. Soldering it to a ≥25mm² GND copper pour reduces R_θJB to 85.7°C/W. Leaving it unconnected raises junction temperature by up to 45°C at full 300mA load, risking thermal shutdown in enclosed environments.