Diodes Incorporated AP4306AKTR-G1

Overview

AP4306AKTR-G1 from Diodes Incorporated is a constant voltage/constant current (CV/CC) controller IC for offline SMPS applications, integrating dual op-amps, a 1.21V voltage reference, and a 70mV current-sense reference. It operates from 2.5V to 18V supply, consumes 0.5mA typical supply current, and delivers precision CV regulation (±1.2% VREF tolerance at +25°C) and CC limiting via low-side sensing - used in USB wall adapters and portable battery chargers.

For engineers reviewing the AP4306AKTR-G1 datasheet, AP4306AKTR-G1 pinout, AP4306AKTR-G1 application, or AP4306AKTR-G1 equivalent, this page provides verified functional identity, validated SOT26 pin mapping, confirmed CV/CC loop parameters, thermal performance data (θJA = 250°C/W), and direct alternatives with documented electrical differences for charger design validation.

Technical Context

The AP4306AKTR-G1 implements two independent control loops: a voltage loop using an internal 1.21V reference and transconductance gain of 3.5 mA/mV (Gmv), and a current loop using a 70mV reference with 7 mA/mV transconductance (Gmi). Both loops drive a single open-drain VOUT pin capable of sinking up to 50mA.

It supports primary-side regulation in flyback converters without optocoupler feedback, enabling simplified adapter designs. The device features rail-to-rail input common-mode range on VCTRL and ICTRL pins, and operates across –40°C to +105°C ambient temperature with guaranteed VREF drift ≤ ±40mV over full range.

Key Specifications

Pinout & Package

SOT26 (K package), 6-pin surface-mount, 2.82mm × 2.65mm footprint, matte tin-plated leads, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant voltage/constant current controller applications.

Compared with AP4305AKTR-G1, AP4306AKTR-G1 delivers tighter CC regulation and lower standby loss; versus UCC28704DR, it offers simpler implementation and lower system-level component count at the expense of valley-switching optimization.

Availability

AP4306AKTR-G1 is available at Aetrix Electronics and suitable for USB wall adapters, smartphone battery chargers, and IoT power supplies requiring stable component supply, RoHS/Green compliance, and production-ready lead times.

Supply support for AP4306AKTR-G1 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 solutions, with manufacturing certified to IATF 16949 and quality systems aligned to AEC-Q200.

The AP4306 belongs to Diodes' AC-DC controller product line, designed specifically for cost-sensitive, high-volume offline SMPS applications demanding integrated CV/CC regulation without secondary-side feedback.

FAQ

What is the function of the VSENSE pin on AP4306AKTR-G1?

The VSENSE pin provides a fixed 70mV internal reference voltage used to set the current limit threshold in the current control loop. It connects to the inverting input of the current-sense op-amp, enabling precise low-side current sensing via an external sense resistor (RSS). This reference remains stable across temperature (±7mV from –40°C to +105°C), ensuring consistent CC regulation in battery charging applications.

Can AP4306AKTR-G1 replace AP4305AKTR-G1 without circuit changes?

Yes - AP4306AKTR-G1 is pin-compatible and functionally identical to AP4305AKTR-G1 except for its lower 70mV current reference (vs. 100mV), which improves CC accuracy and reduces standby power. No schematic or layout changes are needed; only the current-sense resistor (RSS) value must be adjusted to maintain the same current limit, per RSS = 70mV / I_LIM.

What is the maximum sink current capability of the VOUT pin?

The VOUT pin is an open-drain N-channel output capable of sinking up to 50mA at +25°C (35mA minimum over –40°C to +105°C). This drives optocoupler LEDs or PWM controller enable inputs directly. Its low VOL (≤100mV at 10mA) ensures strong logic-low assertion, and thermal derating is defined by θJA = 250°C/W - limiting continuous 50mA operation to ≤50°C ambient without heatsinking.

Does AP4306AKTR-G1 support primary-side constant current regulation in flyback converters?

Yes - AP4306AKTR-G1 implements primary-side constant current regulation using reflected voltage sampling and the ICTRL/VSENSE loop. By monitoring auxiliary winding voltage proportional to output current, it adjusts VOUT sink current to maintain precise CC without secondary-side current sensing. This is validated in Diodes' Typical Application 2 (DS36792 Rev. 3-2, p.3), supporting 5–20W USB-C chargers.