Diodes Incorporated AP7173-FNG-7

Overview

AP7173-FNG-7 from Diodes Incorporated is a 1.5A low-dropout linear regulator with programmable soft-start, enable input, and open-drain power-good output. It operates with input voltage as low as 1.0V, delivers output from 0.8V to 3.3V, achieves 165mV typical dropout at 1.5A, and maintains ±2% output accuracy across load, line, and temperature. It supports FPGA/DSP power sequencing in post-regulation and multi-rail embedded systems.

For engineers reviewing the AP7173-FNG-7 datasheet, AP7173-FNG-7 pinout, AP7173-FNG-7 application, or AP7173-FNG-7 equivalent, key selection criteria include its dual-supply architecture (VIN/VVCC), soft-start capacitor programmability, PG threshold hysteresis, thermal shutdown behavior, and stability with ≥2.2µF generic output capacitors - critical for low-VIN, high-current sequencing designs.

Technical Context

The AP7173 employs an NMOS pass FET controlled by a separate bias rail (VVCC), enabling ultra-low dropout operation when VVCC ≥ VIN + 3.25V. Its feedback loop references a precision 0.8V internal bandgap, supporting adjustable output via external resistor divider.

Soft-start is implemented as a voltage-controlled ramp generator with fixed 440nA charging current into CSS, yielding monotonic startup. The open-drain PG output asserts low when VOUT falls below 85–94% of nominal, with 3% hysteresis and requires external pull-up.

Key Specifications

Pinout & Package

AP7173-FNG-7 is packaged in a RoHS-compliant, lead-free DFN3030-10 (3.0mm × 3.0mm, 0.5mm pitch) with exposed thermal pad. The package supports high thermal performance (θJA = 35°C/W) when soldered to a large ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7173-FNG-7, AP7361-SPG-13 sacrifices sequencing capability and current rating for lower cost, while XC6210B122MR-G trades programmability and monitoring for ultra-compact size - making AP7173-FNG-7 uniquely suited for FPGA/DSP multi-rail systems requiring precise control and reliability.

Availability

AP7173-FNG-7 is available at Aetrix Electronics and suitable for FPGA power sequencing, DSP I/O regulation, low-VIN sensor nodes, and set-top box memory rails requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AP7173-FNG-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 semiconductor company specializing in discrete, analog, and mixed-signal devices for power management, signal integrity, and connectivity applications.

The AP7173 belongs to Diodes' high-performance LDO portfolio designed specifically for demanding power sequencing in FPGA, DSP, and multi-voltage embedded systems where low dropout, accuracy, and integrated monitoring are essential.

FAQ

What is the minimum VVCC required for full 1.5A output at 0.8V VOUT?

The AP7173 requires VVCC ≥ VIN + 3.25V to achieve specified 165mV dropout at 1.5A. For 0.8V VOUT, VIN must be ≥ 0.8V + 0.165V = 0.965V; thus VVCC ≥ 0.965V + 3.25V = 4.215V. Operation below this VVCC degrades dropout and may limit output current.

Can the EN pin be left unconnected if always enabled?

No. The EN pin must never float. If always enabled, connect EN directly to VCC or IN (provided VIN ≥ 1.1V) with a 0.1µF ceramic capacitor to GND at the pin to suppress noise and prevent unintended shutdown due to coupling.

How does the soft-start capacitor value affect startup behavior?

Soft-start time tSS ≈ 0.8 × CSS / 440nA. A 2.7nF CSS yields ~4.9ms ramp; open circuit gives ~100µs. Larger CSS extends ramp linearly, reducing inrush into downstream capacitance but increasing total power-up time - critical for meeting FPGA configuration timing windows.

Is the AP7173-FNG-7 stable with ceramic output capacitors below 2.2µF?

No. Stability is guaranteed only with ≥2.2µF total output capacitance, regardless of type. Using smaller values risks oscillation or poor transient response. Parallel combinations (e.g., 1µF + 1.2µF) are acceptable if sum ≥2.2µF and ESR is low.