SI3402-B-GMR - 802.3af/at PoE+ PD Controller + DC-DC, 20-QFN | Skyworks
MPN: SI3402-B-GMR ✓ فعالSI3402-B-GMR جائزہ
A PoE PD controller is a specialized PMIC that negotiates IEEE 802.3af/at classification with the Power Sourcing Equipment (PSE), controls the hot-swap turn-on sequence with controlled inrush, and then converts the 48 V Ethernet line voltage into one or more usable system rails (commonly 5 V, 12 V, or 3.3 V). Within the broader taxonomy, the SI3402-B sits in the PMIC family of power management ICs, more specifically the Power-over-Ethernet controller sub-category, which in turn belongs to the industrial Ethernet and IP-phone/IoT power-supply hierarchy. Compared with a discrete hot-swap + buck-converter implementation, the SI3402-B reduces BOM count, lowers PCB area, and provides a single silicon reference design that has been pre-qualified for radiated EMI.
Key differentiating features include 100 V absolute-maximum transient survivability on the line side, an internal 0.5 ohm hot-swap switch, an integrated low-EMI switching regulator with synchronous rectifier, and a dedicated maintain-power-signature (MPS) current source. The device implements the full 802.3-2012 Type 1 detection, classification, and operating-mode state machine, and supports both isolated and non-isolated flyback or buck topologies. A thermal-shutdown block and undervoltage lockout complete the protection suite, allowing the IC to be safely deployed on heat-constrained PoE load boards without external supervisory circuitry.
The architecture combines an analog current-mode PWM controller, a 100 V-rated internal hot-swap FET, and a 0.6 A internal switching element, with a precision bandgap-derived reference for the classification signature. The low-EMI gate-drive scheme limits dV/dt on the switching node, allowing designers to meet EN 55022 / FCC Part 15 Class B without complex shielding. Because the switching FET and hot-swap FET are integrated, case-temperature rise is dominated by output power and PCB copper area, making thermal layout the single most critical design variable.
Typical applications include IP phones, wireless access points, PoE-powered security cameras, IoT gateways, and industrial sensors that harvest power from a structured Ethernet cable. Each application benefits from the integrated topology: dropping the part count, shrinking the board, and removing the design risk of a discrete 100 V hot-swap design. The wide input range also supports non-standard 50 V and 54 V rail systems.
When designing with this device, allocate at least 1 square inch of inner-layer copper to dissipate Class-3 full-load power, and follow Skyworks application note AN956 (Using the Si3402-B in Isolated and Non-Isolated Designs) for the recommended transformer, snubber, and feedback component selections. Designers transitioning from the obsolete SI3402-A can reuse the same PCB layout, with only modest resistor and capacitor value changes per the cross-reference guide.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on a typical distributor product listing, and cross-references the part against the published Skyworks datasheet.
کے لیے ڈراپ اِن متبادل SI3402-B-GMR — یکساں پیکیج، پن سے پن مطابقت پذیر۔ مختلف پیکیج والے پرزے جن کے لیے PCB دوبارہ کام درکار ہو، شامل نہیں ہیں۔
اس سیریز میں مختلف ورژن
اسی سیریز کے ماڈلز جو ڈراپ اِن مطابقت رکھتے ہیں SI3402-B-GMR (یکساں فارم فیکٹر اور فٹ پرنٹ) — میں مختلف Maximum Output Power, Package, Product Type, Operating Temperature, Input Voltage Range (PoE).
SI3402-A-GM
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →SI3402-B-GM
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →SI3402-B-GMR
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →SI3402-B-GMR زیادہ سے زیادہ ریٹنگز اور برقی خصوصیات
| Product Type | PoE PD Controller + DC-DC Switching Regulator |
| Standard Compliance | IEEE 802.3af / 802.3at (PoE+ Type 1) |
| Number of Channels | 1 |
| Input Voltage Range (PoE Line) | 37 V to 57 V |
| Absolute Maximum Input Voltage | 100 V (transient) |
| Maximum Output Power | 13 W (Class 3) |
| Supported PD Classes | Class 0, 1, 2, 3 |
| Hot-Swap FET | Internal, integrated |
| Switching FET | Internal, integrated |
| Output Topology | Isolated or non-isolated flyback/buck (configurable) |
| پیکیج | 20-QFN, 5x5 mm |
| ماؤنٹنگ ٹائپ | Surface Mount |
| آپریٹنگ درجہ حرارت | -40C to +85C |
| MSL لیول | MSL 3 (per JEDEC J-STD-020) |
| RoHS اسٹیٹس | Compliant |
SI3402-B-GMR پن کنفیگریشن
| پن 1 | SP1 — Line-side sense input 1 (return) |
| پن 2 | SP2 — Line-side sense input 2 |
| پن 3 | CT1 — Detection/classification pin 1 |
| پن 4 | CT2 — Detection/classification pin 2 |
| پن 5 | VSS — Ground |
| پن 6 | VDD — Bias supply (decoupled) |
| پن 7 | NC — Not connected (per datasheet) |
| پن 8 | FB — Feedback input for output regulation |
| پن 9 | COMP — Compensation network node |
| پن 10 | RT — Oscillator timing resistor |
| پن 11 | CS — Current sense input |
| پن 12 | GATE — Gate drive for external sync FET (optional) |
| پن 13 | DRAIN — Internal switching FET drain |
| پن 14 | SOURCE — Internal switching FET source |
| پن 15 | PGND — Power ground |
| پن 16 | AUX — Auxiliary winding sense (isolated flyback) |
| پن 17 | VDDH — Hot-swap high-side supply |
| پن 18 | VPORT — Port voltage sense |
| پن 19 | VMAIN — Main rail after hot-swap |
| پن 20 | EP — Exposed pad (thermal/ground) |
عام استعمالات
SI3402-B-GMR کے لیے موزوں ہے 8 ایپلیکیشنs: IP Phones (VoIP Terminals), Wireless Access Points, PoE-Powered Security Cameras, IoT Gateways and Edge Nodes, Industrial PoE Sensors, Point-of-Sale Terminals, Smart Lighting Controllers, Building Automation Controllers.
IP Phones (VoIP Terminals)
The SI3402-B-GMR is purpose-built for IEEE 802.3af Class 0-3 powered IP phones that draw up to 13 W from a structured Ethernet cable. Its integrated hot-swap FET, two-step inrush current limiter, and Class signature generation eliminate the discrete front-end that historically occupied 30-40 percent of IP-phone PCB area. According to the Skyworks datasheet, the part's maintain-power-signature (MPS) current source prevents the PSE from removing power during light-load idle states, which is critical for always-on VoIP endpoints. Designers can run the part in either isolated or non-isolated flyback topology, enabling both safety-isolated and cost-optimized PoE+ phone architectures.
تجویز کردہ
Wireless Access Points
Enterprise Wi-Fi 6/6E access points are routinely powered by PoE+ to avoid separate AC adapters at ceiling-mount locations, and the SI3402-B-GMR targets this exact use case. Its integrated 100 V hot-swap FET tolerates cable discharge transients, and its low-EMI PWM gate-drive scheme meets EN 55022 / FCC Part 15 Class B without complex shielding - critical for access points that mount adjacent to antennas. Per the Skyworks datasheet, the device delivers the full Class 3 (13 W) power envelope needed by dual-radio APs with Bluetooth and Zigbee radios. A single 5x5 mm QFN footprint replaces 15-20 discrete components, freeing board area for RF chains and thermal vias.
تجویز کردہ
PoE-Powered Security Cameras
Outdoor PoE IP cameras typically run on Class 3 (13 W) budgets to drive the image sensor, IR illuminator LEDs, and a small heater fan. The SI3402-B-GMR's integrated hot-swap interface and DC-DC converter collapse the power front-end into a single 5x5 mm footprint, leaving room for the camera's CMOS sensor and lens assembly. According to the manufacturer datasheet, the device's 100 V transient rating and integrated TVS-friendly topology simplify the surge-protection network required by outdoor installations. The MPS current source keeps the PSE connection alive during night-time standby, eliminating the camera-dropout failures that plague discrete designs.
تجویز کردہ
IoT Gateways and Edge Nodes
Industrial IoT gateways aggregating multiple sensor buses (RS-485, I2C, SPI, GPIO) benefit from PoE power delivery because the Ethernet cable carries both data and 48 V power. The SI3402-B-GMR's 13 W output budget is well matched to gateways with a small cellular modem or LoRa radio, and its -40C to +85C industrial temperature rating supports outdoor enclosure deployment. The device's two-step inrush limiter protects against legacy pre-standard PSE equipment, which is still common in older industrial switches. Per Skyworks AN956, the chip's low-EMI signature eliminates the need for mu-metal shielding around the IoT gateway enclosure.
تجویز کردہ
Industrial PoE Sensors
Factory-floor PoE sensors for vibration, gas, flow, and temperature monitoring run reliably from the SI3402-B-GMR's Class 3 (13 W) output. The device's integrated architecture reduces the sensor enclosure's PCB to a single side, enabling M12-connector form factors that industrial users prefer. According to the Skyworks datasheet, the chip's 100 V line-side transient rating matches the surge-immunity requirements of IEC 61000-4-5 in industrial environments. The internal thermal shutdown and undervoltage lockout blocks free designers from adding external supervisory ICs, shrinking the BOM and improving MTBF.
تجویز کردہ
Point-of-Sale Terminals
Retail point-of-sale (POS) terminals increasingly deploy as PoE-powered countertop devices to remove the AC adapter and simplify cable management. The SI3402-B-GMR's 13 W budget supports terminals with a small thermal printer, magnetic-stripe reader, and 7-inch customer-facing display. Per the Skyworks datasheet, the device's low-EMI gate-drive enables compliance with FCC Part 15 in retail environments where multiple POS terminals share AC outlets with sensitive payment-card equipment. The integrated maintain-power-signature ensures the terminal stays online during idle periods, avoiding customer-visible boot cycles.
تجویز کردہ
Smart Lighting Controllers
PoE-powered smart lighting fixtures and DMX lighting controllers use the SI3402-B-GMR to harvest up to 13 W from structured Ethernet cabling for LED drivers and control electronics. The device's -40C to +85C operating range handles the thermal stress of ceiling-enclosed lighting fixtures, and its 100 V transient rating tolerates the surge events common in building wiring. According to the Skyworks datasheet, the integrated switching regulator drives the LED current-source FETs directly, eliminating a downstream buck stage. Designers can power 5-10 W LED loads with Class 2 (7 W) and Class 3 (13 W) signatures, with the same silicon doing both.
تجویز کردہ
Building Automation Controllers
HVAC controllers, BACnet gateways, and access-control panels mount in building ceilings and benefit from PoE power to avoid separate low-voltage wiring. The SI3402-B-GMR's 13 W Class-3 budget covers a small controller with a wireless transceiver for KNX, Zigbee, or LoRaWAN backhaul. Per the manufacturer datasheet, the chip's two-step inrush limiter is fully compatible with pre-standard PoE switches still deployed in older buildings. The integrated low-EMI signature makes it suitable for installation in proximity to RF antennas and audio/video distribution equipment without additional shielding.
تجویز کردہ
تجویز کردہ پروڈکٹس کا خلاصہ
کے لیے انجینئرنگ ریفرنس ڈیٹا SI3402-B-GMR — موازنہ، ڈیزائن رہنمائی، اور تعمیل کی معلومات۔
انتخاب کی گائیڈ
متبادلات کے ساتھ موازنہ
| پیرامیٹر | یہ پروڈکٹ | SI3402-A-GM | SI3402-B-GM | SI3402-B-GMR |
|---|---|---|---|---|
| Package | 20-QFN (5x5 mm) | 20-QFN (5x5 mm) - same | 20-QFN (5x5 mm) - same | 20-QFN (5x5 mm) - same |
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions |
| Standard Compliance | IEEE 802.3af/at Type 1 | IEEE 802.3af | IEEE 802.3af/at Type 1 | IEEE 802.3af/at Type 1 |
| Maximum Output Power | 13 W (Class 3) | 13 W (Class 3) | 13 W (Class 3) | 13 W (Class 3) |
| Input Voltage Range | 37 V to 57 V | 37 V to 57 V | 37 V to 57 V | 37 V to 57 V |
| Hot-Swap FET | Integrated | Integrated | Integrated | Integrated |
| Lifecycle Status | Active | Obsolete | Active | Active |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
اہم امتیازی خصوصیات
- Fully-integrated hot-swap FET + switching FET in a single 5x5 mm QFN (بمقابلہTI TPS2373)
- Pin-compatible upgrade path for obsolete SI3402-A designs (بمقابلہSI3402-A-GM)
- Two-step inrush limiter for legacy pre-standard PSE compatibility (بمقابلہON Semi NCP1090)
ڈیزائن نوٹس
Because the Si3402-B integrates both the hot-swap FET and the switching FET, case temperature rise is dominated by output power and PCB copper area rather than by ambient airflow. At Class 3 full-load (13 W), allocate at least 1 square inch of inner-layer copper connected to the exposed pad (EP) to keep junction temperature below the 150 C shutdown threshold. Estimate: with 0.5 W internal dissipation at Class 3 and the QFN-20 5x5 mm thermal pad, junction-to-ambient theta-JA is roughly 35 C/W on a 2-layer 1-oz board, and 25 C/W on a 4-layer 1-oz board. Designers targeting enclosed IP-camera housings should measure case temperature with a thermocouple on EP at worst-case ambient.
Follow Skyworks application note AN956 (Using the Si3402-B in Isolated and Non-Isolated Designs) for the recommended transformer, snubber, and feedback component selections. Place the 0.1 uF VDD decoupling capacitor within 2 mm of the VDD pin, and route the CS (current sense) trace as a Kelvin connection directly to the SOURCE pin to avoid ground bounce errors. Keep the switching-node copper area minimal to reduce radiated EMI; the integrated low-EMI gate drive helps meet EN 55022 / FCC Part 15 Class B but does not eliminate the need for careful PCB layout.
When migrating from the obsolete SI3402-A to the SI3402-B, do NOT assume the PCB will work unmodified. The Skyworks cross-reference guide explicitly states that some external resistor and capacitor value changes are required, particularly around the CT1/CT2 detection pins and the FB feedback divider. Also, do not exceed the 100 V absolute maximum input voltage during cable discharge events - always include a TVS diode (e.g., SMAJ58CA) on the line side for surge protection per IEC 61000-4-5.
The SI3402-B implements the IEEE 802.3-2012 detection signature (25 kohm resistor) and 4-class classification signature (Class 0-3). For designs that may connect to pre-standard PoE equipment, the integrated two-step inrush current limiter protects the hot-swap FET from the high di/dt that legacy PSEs apply. Maintain-power-signature (MPS) is generated automatically by the chip, preventing the PSE from removing power during light-load idle states - critical for always-on VoIP phones and IP cameras that sleep between transactions.
The Si3402-B uses a proprietary low-EMI gate-drive scheme that limits switching-node dV/dt, enabling Class B EMI compliance without complex mu-metal shielding. For designs near sensitive RF or audio circuits, use a common-mode choke (e.g., PFL2015-682ME) on the line side to suppress common-mode noise, and place the bootstrap capacitor close to the integrated switching FET drain-source pins. Spectrum spreading is not user-configurable on this part; for more demanding EMI environments, consider a discrete PoE controller with adjustable frequency jitter.
تعمیل کی معلومات
RoHS compliant per Skyworks product page and DigiKey listing. REACH compliance status not explicitly listed by the manufacturer; consult Skyworks SVHC declaration. AEC-Q100 qualification is not applicable - this is a PoE PD controller for industrial/commercial Ethernet applications, not an automotive-grade IC. JEDEC J-STD-020 MSL 3 moisture-sensitivity-level rating applies per the manufacturer datasheet.
