2021 - Rtl9210b Datasheet
The RTL9210B is famous in the enthusiast community for its superior power management compared to competitors like the JMicron JMS583.
Since the datasheet is NDA, most users rely on the MP Tool (Mass Production Tool) to configure the chip.
Realtek RTL9210B Go to product viewer dialog for this item. is a high-performance USB 3.1 Gen 2 bridge controller designed to connect M.2 NVMe and SATA SSDs to a host system via a single USB Type-C interface. Released in its primary datasheet revision 1.1 in June 2020 and widely adopted in consumer enclosures throughout 2021, the
stands out for its "dual protocol" capability, allowing it to automatically switch between PCIe and SATA modes based on the installed drive. Key Technical Specifications RTL9210B-CG
acts as a bridge between high-speed USB and internal storage interfaces:
Host Interface: USB 3.2 Gen 2 (formerly USB 3.1 Gen 2), supporting transfer speeds up to 10Gbps. Storage Interfaces:
PCI Express: Compatible with Gen 1/Gen 2/Gen 3, utilizing up to 2 lanes (PCIe Gen3x2) for a maximum link speed of 8GT/s per lane. rtl9210b datasheet 2021
SATA: Compatible with SATA Gen 1/Gen 2/Gen 3, supporting a maximum link speed of 6Gbps. Protocol Support:
NVMe: Supports standard command sets, NVM Express Base Specification Rev. 1.3, and SMART health monitoring.
SATA/AHCI: Supports standard AHCI (Advanced Host Controller Interface) for SATA SSDs.
Form Factor Support: Frequently used in enclosures for M.2 SSD sizes 2230, 2242, 2260, and 2280. Features and Power Management
The controller is designed for efficiency and versatility in portable storage solutions:
Auto-Switching (PEDET): Uses the PEDET interface of the M.2 mechanical connector to automatically detect and switch between USB-to-PCIe and USB-to-SATA modes. The RTL9210B is famous in the enthusiast community
Power Delivery: The RTL9210BPD-CG variant specifically supports Power Delivery 3.0 via the Type-C connector.
Energy Efficiency: Includes built-in switching regulators (5V to 1V) and LDOs (5V to 3.3V) to minimize external component requirements. It supports ASPM L1, CLKREQ, and L1 substate power management to reduce consumption during idle periods.
Customization: Supports 32Mbytes external SPI Flash for firmware, customized LEDs (blinking frequency/duty cycle), and GPIO/UART/I2C interfaces for advanced system integration. Performance and Compatibility
Real-world performance typically reaches read speeds of approximately 930–1000 MB/s for NVMe drives, while SATA drives are capped by the 6Gbps interface (approx. 500–560 MB/s).
Realtek published three errata specific to chips manufactured before Week 24 of 2021:
| Errata ID | Issue | Workaround in 2021 Datasheet | | :--- | :--- | :--- | | RTL9210B-E1 | PCIe link fails to negotiate x2 with some Phison E18 controllers | Force Gen 2 x2 by pulling CFG2 (Pin 2) low via 10k resistor | | RTL9210B-E2 | USB 3.1 eye diagram fails with cables >0.8m | Add 1 pF capacitor to ground on USB_SS_TX+/- | | RTL9210B-E3 | I2C EEPROM corruption at power loss | Enable ferrite bead + 470 µF hold-up capacitor on 3.3V rail | Important: The 2021 datasheet clarifies that these errata
Important: The 2021 datasheet clarifies that these errata are not fixed in the silicon. They are design corrections. For fixed silicon, request RTL9210B-CG (2022 revision).
For designers creating a USB-C SSD enclosure, the datasheet emphasizes:
A full stack-up example for a 4-layer board is provided in the 2021 appendix.
The RTL9210B is firmware-dependent. The 2021 datasheet references firmware version 1.23.x as the initial production release, with key capabilities:
Later 2021 revisions (firmware 1.27+) added:
Flashing procedure (from application note AN-2021-09):
Via USB firmware update mode (hold RESET# and GPIO12 low during power-on) or using the Realtek Flash Tool over UART.