Technical FAQ
Plain-language answers to common semiconductor sourcing and technology questions.
What is hardwired TCP/IP?
Hardwired TCP/IP means the entire TCP/IP protocol stack is implemented directly in chip hardware instead of running as software on the MCU. With a chip like the WIZnet W5500, the MCU just moves data over SPI without spending CPU or memory on protocol processing — giving more stable links and simpler development.
View W5500 →What is the difference between W5500 and W5100S?
Both are WIZnet hardwired TCP/IP Ethernet controllers. The W5500 uses an SPI interface with a 32KB buffer and 8 sockets; the W5100S supports both SPI and a parallel interface with a 16KB buffer and 4 sockets. Choose W5100S when you need a parallel bus, otherwise the W5500 is the mainstream choice.
What is Power over Ethernet (PoE)? 802.3af vs at?
PoE delivers both data and power over a single RJ45 cable, removing separate power wiring. IEEE 802.3af supplies about 13W and 802.3at (PoE+) about 25W. A powered device (PD) such as the WIZnet WIZPoE-P1 module takes 36–57V from the cable and outputs a regulated 5V.
PoE design guide →What is a real-time clock (RTC) module?
An RTC module is a dedicated timekeeping chip that continuously tracks date and time on very little current, even when the main system is off. The Micro Crystal RV-3028-C7, for example, integrates a temperature-compensated crystal and draws only about 45nA — ideal for wearables, meters, and battery-powered IoT timekeeping.
View RV-3028-C7 →What is a SiC Schottky diode and why use it?
A silicon-carbide (SiC) Schottky diode is a power diode made from SiC, with virtually no reverse-recovery loss and high temperature and voltage tolerance. Compared with traditional silicon diodes, it cuts losses and raises efficiency in high-frequency, high-efficiency circuits such as PFC, SMPS, solar, and EV charging.
View HSC04065AC →What is LoRaWAN?
LoRaWAN is a low-power wide-area network (LPWAN) protocol built on LoRa radio technology, characterized by long range, low power, and low data rate — ideal for battery-powered sensor nodes. A LoRaWAN gateway such as the KIWI TLG8411V1 aggregates data from many end devices, widely used in smart cities, smart metering, and environmental monitoring.
View LoRaWAN gateway →What is an LDO regulator?
An LDO (low-dropout) regulator is a linear voltage regulator that maintains a stable output even when the input and output voltages are very close, while providing low noise. Simple and clean, LDOs are commonly used for noise-sensitive analog/RF circuits and battery-powered devices, such as the TAEJIN TJ5205.
What is EEPROM?
EEPROM is electrically erasable and writable non-volatile memory that retains data after power-off and can be rewritten byte by byte. It is commonly used to store configuration parameters, calibration data, and serial numbers. The FMD FT24C series, for example, uses a standard I²C interface with capacities from 2K to 256K bit.
Is GigaDevice GD32 compatible with STM32?
The GigaDevice GD32 series (such as GD32F103) uses the same Arm Cortex-M cores and is highly pin-compatible with the corresponding STM32 parts, so in most cases it drops in directly. The GD32F103 runs up to 108MHz with largely compatible peripherals and registers — a common alternative for shortages or cost.
View GD32F103 →What is an ultra-low-power MCU?
An ultra-low-power MCU is a microcontroller designed to maximize battery life, focusing on extremely low sleep-mode current (down to the nA range) and efficient wake mechanisms. The EM Microelectronics EM6819, for example, operates from as low as 0.9V with nA-level sleep current — suited to wearables, smart cards, and IoT sensor nodes.
Who is the authorized distributor for these brands in Taiwan?
JLink Technology is the authorized distributor for WIZnet, EM Microelectronics, DAVICOM, GigaDevice, Micro Crystal, FMD, On-Bright, TAEJIN, KIWI Technology, and Huixin in Taiwan, Mainland China, and Hong Kong, providing genuine parts, datasheets, samples, and technical support.
How do I request a quote, datasheet, or samples?
Fill in the RFQ form on the site with the part number and quantity; JLink Technology typically replies with pricing, lead time, and datasheets within one business day. You can also contact sales directly at +886-2-2228-1559 or [email protected]. Both samples and mass production are supported.
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