SNAS833B November   2021  – August 2025 CDCDB400

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Fail-Safe Input
      2. 7.3.2 Output Enable Control
      3. 7.3.3 SMBus
        1. 7.3.3.1 SMBus Address Assignment
    4. 7.4 Device Functional Modes
      1. 7.4.1 CKPWRGD_PD# Function
      2. 7.4.2 OE[3:0]# and SMBus Output Enables
      3. 7.4.3 Output Slew Rate Control
      4. 7.4.4 Output Impedance Control
    5. 7.5 Programming
  9. 8 Register Maps
    1. 8.1 CDCDB400 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Enable Control Method
        2. 9.2.2.2 SMBus Address
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Examples
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 TICS Pro
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

4 Pin Configuration and Functions



Figure 4-1 CDCDB400 RHB Package32-Pin VQFNTop View
Table 4-1 Pin Functions
PINTYPE(2)DESCRIPTION
NAMENO.
INPUT CLOCK
CLKIN_P3ILP-HCSL differential clock input. Typically connected directly to the differential output of clock source.
CLKIN_N4I
OUTPUT CLOCKS
CK0_P13OLP-HCSL differential clock output of channel 0. Typically connected directly to PCIe differential clock input. If unused, the pins can be left no connect.
CK0_N14O
CK1_P19OLP-HCSL differential clock output of channel 1. Typically connected directly to PCIe differential clock input. If unused, the pins can be left no connect.
CK1_N20O
CK2_P22OLP-HCSL differential clock output of channel 2. Typically connected directly to PCIe differential clock input. If unused, the pins can be left no connect.
CK2_N

23

O
CK3_P27OLP-HCSL differential clock output of channel 3. Typically connected directly to PCIe differential clock input. If unused, the pins can be left no connect.
CK3_N28O
MANAGEMENT AND CONTROL(1)
CKPWRGD_PD#1I, S, PDClock Power Good and Power Down multi-function input pin with internal 180kΩ pulldown. Typically connected to GPIO of microcontroller. If unused, the pin can be left no connect. After PWRGD has been asserted high for the first time, the pin becomes a PD# pin and the pin controls power-down mode:
LOW: Power-down mode, all output channels tri-stated.
HIGH: Normal operation mode.
OE0#
15I, S, PDOutput Enable for channel 0 with internal 180kΩ pulldown, active low. Typically connected to GPIO of microcontroller. If unused, the pin can be left no connect.
LOW: enable output channel 0.
HIGH: disable output channel 0.
OE1#
18I, S, PDOutput Enable for channel 1 with internal 180kΩ pulldown, active low. Typically connected to GPIO of microcontroller. If unused, the pin can be left no connect.
LOW: enable output channel 1.
HIGH: disable output channel 1.
OE2#24I, S, PDOutput Enable for channel 2 with internal 180kΩ pulldown, active low. Typically connected to GPIO of microcontroller. If unused, the pin can be left no connect.
LOW: enable output channel 2.
HIGH: disable output channel 2.
OE3#26I, S, PDOutput Enable for channel 3, with internal 180kΩ pulldown, active low. Typically connected to GPIO of microcontroller. If unused, the pin can be left no connect.
LOW: enable output channel 3.
HIGH: disable output channel 3.
SMBUS AND SMBUS ADDRESS

SADR0

5I, S, PU / PDSMBus address strap bit. This is a 3-level input that is decoded in conjunction with pin B8 to set SMBus address. The pin has internal 180kΩ pullup / pulldown network biasing to GND when no connect.
For a high-level input configuration, the pin must be pulled up to 3.3V VDD through an external pullup resistor from 1k to 5k with 5% tolerance.
For a low-level input configuration input, the pin must be pulled down to ground through an external pulldown resistor from 1k to 5k with 5% tolerance.
For a mid-level input configuration, the pin must be left floating and not connected to VDD or ground.
SMBDAT6I / OData pin of SMBus interface. Typically pulled up to 3.3V VDD using external pullup resistor. The recommended pullup resistor value is > 8.5k.
SMBCLK7IClock pin of SMBus interface. Typically pulled up to 3.3V VDD using external pullup resistor. The recommended pullup resistor value is > 8.5k.
SUPPLY VOLTAGE AND GROUND
VDDR2PPower supply input for input clock receiver. Connect to 3.3V power supply rail with decoupling capacitor to GND. Place a 0.1µF capacitor close to each supply pin between power supply and ground.
VDD12, 16, 21, 25, 29, 31P3.3V power supply for output channels and core voltage.
GNDDAPGGround. Connect ground pad to system ground.
NO CONNECT
NC8, 9, 10, 11, 17, 30—Do not connect pins to GND or VDD. Leave floating.
NC32—Pin can be connected to GND, VDD, or otherwise tied to any potential within the Supply Voltage range stated in the Absolute Maximum Ratings.
(1) The “#” symbol at the end of a pin name indicates that the active state occurs when the signal is at a low voltage level. When “#” is not present, the signal is active high.
(2) The definitions below define the I/O type for each pin.
  • I = Input
  • O = Output
  • I / O = Input / Output
  • PU / PD = Internal 180kΩ pullup / Pulldown network biasing to VDD/2
  • PD = Internal 180kΩ pulldown
  • S = Hardware Configuration Pin
  • P = Power Supply
  • G = Ground