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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Diodes Incorporated AP7348D-3318RS4-7

Name: AP7348D-3318RS4-7
Brand: Diodes Incorporated
SKU: AP7348D-3318RS4-7
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7348D-3318RS4-7

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: 8-XFDFN Exposed Pad

Datasheet:: AP7348D-3318RS4-7.pdf

Description:: LDO CMOS LOWCURR X1-DFN1612-8 T&

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7348D-3318RS4-7 from Diodes Incorporated is a quad-channel low-dropout linear regulator IC with independent enable control per pair of outputs (EN1 for VOUT1/VOUT3, EN2 for VOUT2/VOUT4), ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). It delivers 300mA per channel across a 1.7V–5.25V input range and is optimized for RF supply in LPWAN/IoT modules where clean, stable multi-rail power is critical.

For engineers reviewing the AP7348D-3318RS4-7 datasheet, AP7348D-3318RS4-7 pinout, AP7348D-3318RS4-7 application, or AP7348D-3318RS4-7 equivalent, this device supports simultaneous dual-rail sequencing (3.3V/1.8V), thermal shutdown per channel, foldback current limiting, and auto-discharge on disable - key considerations for compact battery-powered communication systems.

Technical Context

The AP7348D-3318RS4-7 integrates two independent CMOS-based LDO regulators per enable input: EN1 controls VOUT1 (3.3V) and VOUT3 (3.3V); EN2 controls VOUT2 (1.8V) and VOUT4 (1.8V). Each channel features its own error amplifier, foldback current limit (~55mA short-circuit clamp), and dedicated discharge path via 10Ω internal N-channel FET when disabled.

Thermal protection operates per-channel with +155°C shutdown threshold and +25°C hysteresis; overtemperature fault disables all four outputs. Input voltage range (1.7V–5.25V), ultra-low quiescent current (160µA total), and high PSRR (75dB @ 1kHz) reflect design intent for noise-sensitive RF and baseband subsystems requiring rail isolation and fast transient response.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	VOUT1/VOUT3 = 3.3V fixed; VOUT2/VOUT4 = 1.8V fixed - enables dual-rail power for SoC core + I/O or RF transceiver + baseband logic
Output Accuracy	±1% at TA = +25°C - ensures reliable operation of 1.8V digital interfaces and 3.3V analog/RF circuitry without margining overhead
PSRR	75dB at 1kHz - suppresses switching noise from upstream DC/DC converters feeding VDD, critical for RF receiver sensitivity
Output Noise	60µV_rms (10Hz–100kHz) - minimizes phase noise contribution in local oscillator supply rails
Dropout Voltage	0.25V max at 300mA (for 3.0–3.6V outputs); 0.28V max (for 2.0–2.5V outputs) - supports operation from single-cell Li-ion or buck converter outputs down to ~2.0V
Quiescent Current	160µA typical total - extends battery life in always-on IoT sensor nodes and standby modes
Enable Logic	EN1 high → VOUT1 & VOUT3 active; EN2 high → VOUT2 & VOUT4 active - allows independent power sequencing and dynamic rail gating

Pinout & Package

X1-DFN1612-8 (Type B) 1.6mm × 1.2mm, 0.4mm pitch, thermally enhanced package with exposed thermal pad (electrically isolated or grounded).

Pin/Terminal	Circuit Role	Design Meaning
1 GND	Power ground reference	Primary return path for all four channels; must connect to low-impedance PCB ground plane
2 VOUT3	Channel 3 regulated output	3.3V fixed output (CH3), shares EN1 control with VOUT1; requires local 1µF ceramic capacitor
3 VOUT4	Channel 4 regulated output	1.8V fixed output (CH4), shares EN2 control with VOUT2; independent from CH1/CH3 rail
4 EN2	Enable input for CH2 & CH4	Active-high logic; drives CH2 (VOUT2) and CH4 (VOUT4) simultaneously; 0–0.5V = disable, 1.3–5.25V = enable
5 VOUT2	Channel 2 regulated output	1.8V fixed output (CH2), shares EN2 control with VOUT4; supports low-voltage logic domains
6 VDD	Main power input	Common input for all four LDOs; requires 4.7µF ceramic decoupling capacitor placed adjacent to pin
7 VOUT1	Channel 1 regulated output	3.3V fixed output (CH1), shares EN1 control with VOUT3; supplies RF front-end or interface peripherals
8 EN1	Enable input for CH1 & CH3	Active-high logic; drives CH1 (VOUT1) and CH3 (VOUT3) simultaneously; enables dual 3.3V rail control

Key Features

Feature	Design Value
Per-channel thermal shutdown	+155°C trip with +25°C hysteresis - prevents latch-up during sustained overload while allowing safe recovery after cooling
Independent discharge FETs	10Ω on-resistance per channel during disable - rapidly discharges output capacitors to prevent back-powering or latch-up in sequenced systems
Low-noise CMOS architecture	60µV_rms noise floor - eliminates need for additional post-regulation filtering in sensitive RF/analog signal chains
Foldback current limiting	~55mA short-circuit clamp - limits power dissipation during fault conditions without triggering global thermal shutdown
High PSRR at audio frequencies	75dB @ 1kHz - rejects ripple from switching converters operating at common frequencies (e.g., 500kHz–2MHz with harmonics)

Applications

Smartphone Baseband Power

LPWAN Transceiver Supply

Use Scenario: Dual-rail power for application processor (1.8V core) and RF transceiver (3.3V PA bias) in compact cellular IoT modules.

IC Role / Device Role / Timing Role: Quad-LDO provides isolated, low-noise 1.8V and 3.3V rails with independent enable control for power-state coordination.

Use Value: Eliminates cross-rail coupling; enables fast wake/sleep transitions via EN1/EN2 without external MOSFETs or sequencing ICs.

Use Scenario: Powering sub-GHz LoRa/Wi-SUN transceivers where RF supply cleanliness directly impacts receive sensitivity and BER.

IC Role / Device Role / Timing Role: Delivers ultra-low-noise 3.3V supply to RF synthesizer and 1.8V to digital baseband, rejecting DC/DC switching artifacts.

Use Value: 60µV_rms noise and 75dB PSRR maintain >110dBm receiver sensitivity without added ferrite beads or LC filters.

Wi-Fi 6 IoT Access Point

Industrial Camera Module

Use Scenario: Multi-rail power for Wi-Fi 6 SoC (1.8V MAC, 3.3V PHY/PA) in battery-backed edge gateway devices.

IC Role / Device Role / Timing Role: Provides tightly regulated, sequenced 1.8V and 3.3V outputs with thermal monitoring per channel during burst transmit.

Use Value: Per-channel OTP prevents single-fault propagation; 160µA quiescent current extends battery runtime in low-duty-cycle deployments.

Use Scenario: Powering image sensor (1.8V analog, 3.3V I/O) and ISP (1.2V core, 1.8V memory) in compact surveillance cameras.

IC Role / Device Role / Timing Role: Supplies clean, accurate 1.8V and 3.3V rails with fast load transient response (<50µs settling) for pixel readout stability.

Use Value: Low dropout (0.25V @ 300mA) enables use with 3.6V Li-ion input; 1% accuracy ensures consistent ADC reference and sensor biasing.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6216D3318MR-G	Single enable per channel (4 EN pins), no thermal shutdown per channel, 50µV_rms noise, 70dB PSRR @ 1kHz	Lacks integrated thermal fault coordination across rails; requires external sequencing logic for multi-rail startup	Preferred when discrete enable control per rail is required and per-channel thermal safety is not mandated
Ricoh RP517K3318D-TR	Fixed 3.3V/1.8V outputs, 120µA total IQ, 65dB PSRR @ 1kHz, no auto-discharge FETs	No output discharge on disable - risks back-powering or latch-up in systems with shared ground paths	Selected for cost-sensitive designs where fast rail discharge is handled externally and PSRR >70dB is acceptable

Compared with XC6216D3318MR-G and RP517K3318D-TR, the AP7348D-3318RS4-7 uniquely combines per-channel thermal shutdown, dual-pair enable architecture, and integrated discharge FETs - enabling safer, simpler, and more robust multi-rail power management in space-constrained wireless modules.

Availability

AP7348D-3318RS4-7 is available at Aetrix Electronics and suitable for LPWAN transceiver supply, smartphone baseband power, and industrial camera module applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7348D-3318RS4-7 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 ICs for power management, signal integrity, and connectivity applications.

The AP7348 belongs to Diodes' high-PSRR, low-noise LDO family designed specifically for noise-sensitive RF, IoT, and portable communication systems requiring multi-rail precision regulation in ultra-small packages.

FAQ

What are the exact output voltages configured in AP7348D-3318RS4-7?

The suffix "3318" indicates VOUT1 and VOUT3 are factory-set to 3.3V, while VOUT2 and VOUT4 are set to 1.8V. These are fixed-output voltages defined by internal resistor networks; no external feedback components are used or supported. Output accuracy is ±1% at +25°C and maintained across -40°C to +85°C ambient.

How does the dual-enable architecture affect power sequencing?

EN1 independently controls VOUT1 and VOUT3 (both 3.3V), while EN2 controls VOUT2 and VOUT4 (both 1.8V). This allows two-stage sequencing - e.g., powering 3.3V RF circuitry before 1.8V baseband logic - without external timing components. Each enable pin has defined thresholds (0–0.5V low, 1.3–5.25V high) and leakage <±1.0µA.

Can AP7348D-3318RS4-7 operate from a 2.5V input supplying 1.8V outputs?

Yes. At 300mA load, dropout for 1.8V outputs is 0.28V max (2.5V – 1.8V = 0.7V headroom), well above the 0.28V worst-case specification. The device operates down to 1.7V input, supporting single-cell Li-ion (2.7–4.2V) and buck converter outputs. Thermal limits (600mW max PD) must be observed at high IOUT and low V_IN–V_OUT.

Is the thermal pad electrically connected, and how should it be handled in layout?

The thermal pad is electrically isolated from all pins and may be left floating or connected to GND for improved thermal performance. It must be soldered to a PCB copper pour for heat dissipation; θ_JA is 160°C/W with JEDEC High-K board. Do not omit the dedicated GND pin (Pin 1) - the thermal pad supplements, but does not replace, the primary ground connection.

AP7348D-3318RS4-7 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 8-XFDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 4

Voltage - Input (Max):: 5.25V

Voltage - Output (Min/Fixed):: 3.3V, 3.3V, 1.8V, 1.8V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.33V @ 300mA, 0.33V @ 300mA, 0.48V @ 300mA, 0.48V @ 300mA

Current - Output:: 300mA, 300mA, 300mA, 300mA

Current - Quiescent (Iq):: 280 µA

Current - Supply (Max):: -

PSRR:: 75dB (1kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature, Short Circuit

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: X1-DFN1612-8 (Type B)

AP7348D-3318RS4-7 FAQ

1.How can I place an order for AP7348D-3318RS4-7 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7348D-3318RS4-7 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AP7348D-3318RS4-7 reliable?

The price and inventory of AP7348D-3318RS4-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7348D-3318RS4-7 is usually 5 days.

3.What payment methods are accepted for AP7348D-3318RS4-7?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7348D-3318RS4-7 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7348D-3318RS4-7?

AP7348D-3318RS4-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7348D-3318RS4-7 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AP7348D-3318RS4-7?

For technical support, including AP7348D-3318RS4-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7348D-3318RS4-7 requirements.

6.How does Aetrix verify that AP7348D-3318RS4-7 is sourced from the original manufacturer or authorized distributors?

All AP7348D-3318RS4-7 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AP7348D-3318RS4-7 meets industry standards.

7.What is the process for return or replacement of AP7348D-3318RS4-7?

All AP7348D-3318RS4-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP7348D-3318RS4-7, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AP7348D-3318RS4-7 part is unused and in its original packaging.

Return procedure for AP7348D-3318RS4-7:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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