Diodes Incorporated AP7340-185FS4-7

Overview

AP7340-185FS4-7 from Diodes Incorporated is a fixed-output 1.85V, 150mA 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, low 35µA quiescent current, and operates from 1.7V to 5.25V input - optimized for RF supply rails in portable wireless communication devices.

For engineers reviewing the AP7340-185FS4-7 datasheet, AP7340-185FS4-7 pinout, AP7340-185FS4-7 application, or AP7340-185FS4-7 equivalent, key selection criteria include dropout voltage at 150mA (0.21–0.27V for 1.85V output), EN logic thresholds (0.5V_IL/1.3V_IH), thermal performance in X2-DFN1010-4, and stability with 0.47µF ceramic C_IN/C_OUT.

Technical Context

The AP7340-185FS4-7 integrates a precision voltage reference, error amplifier, and current-limit circuit in a single CMOS LDO architecture. Its non-discharge output stage eliminates automatic V_OUT discharge during shutdown, preserving downstream capacitor charge for fast wake-up sequences in battery-powered systems.

It delivers regulated 1.85V output with line regulation of ≤0.1%/V and load regulation of ≤1.0%/A across –40°C to +85°C ambient. The EN pin supports direct microcontroller GPIO control with leakage <±1.0µA and defined turn-on/turn-off thresholds, enabling precise power sequencing in multi-rail portable designs.

Key Specifications

Pinout & Package

The AP7340-185FS4-7 is housed in a 1.0mm × 1.0mm, 0.4mm height X2-DFN1010-4 package with exposed thermal pad. This ultra-compact lead-free RoHS-compliant package supports high-density PCB layouts and requires thermal copper pour connected to GND for optimal power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6210B185MR-G, the AP7340-185FS4-7 uniquely combines exact 1.85V output, integrated EN, 75dB PSRR, and thermal-pad-enhanced package - making it optimal for RF-critical, space-constrained portable designs requiring precise voltage matching and active power control.

Availability

AP7340-185FS4-7 is available at Aetrix Electronics and suitable for RF supply, camera ISP, and portable media player applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7340-185FS4-7 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 communications markets.

The AP7340 series belongs to Diodes' high-PSRR, low-noise LDO portfolio designed specifically for noise-sensitive RF and imaging subsystems in battery-powered portable electronics.

FAQ

What is the maximum input voltage rating for AP7340-185FS4-7?

The absolute maximum input voltage is 6.0V per the datasheet Absolute Maximum Ratings table. Operation beyond 5.25V violates Recommended Operating Conditions and risks permanent damage. For reliable long-term use, VIN must remain between 1.7V and 5.25V, with 1.85V + dropout (≥2.12V) as the practical minimum under 150mA load.

Does AP7340-185FS4-7 include output discharge functionality?

No. AP7340-185FS4-7 is the non-discharge variant (standard AP7340). It lacks an internal pull-down transistor on VOUT; during EN=low shutdown, the output remains floating at its last charged voltage. The discharge version is designated AP7340D-185FS4-7 and actively discharges VOUT via a 30Ω internal NMOS when disabled.

Can AP7340-185FS4-7 operate with ceramic capacitors smaller than 0.47µF?

The datasheet specifies 0.47µF as the minimum recommended value for both C_IN and C_OUT to guarantee stability and transient response across temperature and load. Using smaller values may cause oscillation or degraded PSRR/noise performance, especially under 100mA+ dynamic loads. No smaller-value validation is provided in DS35282 Rev. 5–2.

How is thermal performance affected by the X2-DFN1010-4 package's thermal pad?

The exposed thermal pad significantly improves θ_JA - when soldered to ≥100mm² of 1oz copper connected to GND, junction-to-ambient thermal resistance drops to ~200°C/W (vs. >300°C/W without pad connection). This allows continuous 150mA operation at +85°C ambient, whereas omitting pad connection limits safe current to ~90mA at same temperature.