CH334

Part: CH334/CH335 — WCH

Type: 4-port USB HUB Controller

Description: A 4-port USB 2.0 HUB controller chip supporting high-speed 480Mbps, full-speed 12Mbps, and low-speed 1.5Mbps, with high-performance MTT mode, industrial-grade design, and minimal external components.

Operating Conditions:

• Supply voltage: 3.3V (internal operating power, can be powered from USB bus)
• Operating temperature: -40 to 85 °C
• USB speed: Up to 480Mbps

Absolute Maximum Ratings:

• Max junction/storage temperature: 85 °C (operating maximum)

Key Specs:

• USB Protocol: USB2.0 compliant, backward compatible with USB1.1
• Upstream Port Speed: 480Mbps (high-speed), 12Mbps (full-speed), 1.5Mbps (low-speed)
• Downstream Port Speed: 480Mbps (high-speed)
• Downstream Ports: 4
• TT Mode: Supports high-performance MTT (4 TTs) and low-cost STT (single TT)
• Clock: Built-in professional high-precision clock, supports external 12MHz input
• ESD Performance: USB pins 6KV enhanced ESD, Class 3A
• Internal LDO: Converts USB bus power voltage to 3.3V operating power

Features:

• Supports independent or GANG overall power control and overcurrent detection for each port.
• Port status LED indicators.
• Configurable via external EEPROM (VID, PID, port configuration) or built-in information memory.
• Crystal-free application option.
• CH335 supports MCU control to swap the upstream port with the 1# downstream port.

Applications:

• Computer and industrial PC motherboards
• Peripherals
• Embedded systems

Package:

• QSOP16
• QSOP28
• SSOP28
• QFN16C_2x2
• QFN16_3x3
• QFN24_4x4
• QFN28_4x4
• QFN28_5x5
• QFN36_6x6
• LQFP48

• 4-port USB hub, providing 4 USB2.0 downstream ports, backward compatible with USB1.1 protocol specification.
• Supports independent power control for each port or GANG overall linked power control.
• Supports independent overcurrent detection for each port or GANG overall overcurrent detection, supports 5V tolerant overcurrent signal input.
• Supports high-performance MTT mode, providing an independent TT for each port to achieve full-bandwidth concurrent transmission, with a total bandwidth 4 times that of STT.
• Supports port status LED indicators.
• Can be configured via external EEPROM to support composite devices, non-removable devices, custom VID, PID, and port configuration.
• Built-in information memory, allowing for batch customization of manufacturer or product information and configuration for special industry needs, without the need for EEPROM.
• Self-developed dedicated USB PHY, LPM low-power consumption technology, significantly reduced compared to the first-generation HUB chips, supports self-powered or bus-powered operation.
• Can be configured for self-powered or bus-powered mode via I/O pins or external EEPROM.
• Provides a crystal oscillator, built-in capacitors, supports external 12MHz input, built-in PLL provides 480MHz clock for USB PHY.
• Built-in professional high-precision clock, allows for removal of external 12MHz crystal, saving cost, reducing size, and lowering EMI.
• Upstream port has a built-in 1.5KΩ pull-up resistor, downstream ports have built-in pull-down resistors required by USB Host, simplifying external components.
• Built-in LDO linear step-down regulator, which can convert the USB bus power voltage to the chip's 3.3V operating power.
• CH335 supports MCU control to swap the upstream port with the 1# downstream port.
• USB pins have 6KV enhanced ESD performance, Class 3A.
• Industrial operating temperature range: -40 ~ 85 °C.
• Available in various package types such as QFN28, QFN24, QFN16, QSOP28.

Table 1-3 Pin Definition