Product Errata LTC2000 Start-Up Issue Reported: July 2015 Resolved: September 2015 Update: This LTC2000 issue was corrected beginning with product date code 1536. ISSUE DESCRIPTION In some LTC®2000 devices the clock synchronizer and dynamic linearization circuits may not start-up correctly after supply voltages are first applied. This issue may be diagnosed by reading SPI address 0x05. If these circuits fail to start-up, bit 3 of address 0x05 will read back high. This issue may result in corruption of the data received at the LVDS input ports, resulting in large errors at the DAC output. The issue may further prevent the dynamic linearization circuits from operating, resulting in increased harmonic distortion at the DAC output. Suggested workarounds are described in the following section. The LTC2000 is being revised to correct this issue. Modified Start-Up Sequence using PD pin: 1a. Apply valid supply voltages to AVDD33, DVDD33, AVDD18, DVDD18, and SVDD. 1b.Set the PD pin low to power down the LTC2000. 1c. Set the PD pin high to power up the LTC2000. 2. Write 0x01 to address 0x01 to perform a software reset. 3. Follow steps 3 through 10 of the startup sequence on page 34 of the LTC2000 data sheet. Modified Start-Up Sequence using SPI: 1a. Apply valid supply voltages to AVDD33, DVDD33, AVDD18, DVDD18, and SVDD. 1b.Write 0x04 to address 0x01 to set FULL_PD=1. 2. Write 0x01 to address 0x01 to perform a software reset. WORKAROUNDS It is possible to work around this issue by using a modified version of the sample start-up sequence provided on page 34 of the LTC2000 data sheet. The modified start-up sequence powers down the part after valid supply voltages have been applied, using either the PD pin or the FULL_PD bit in SPI register 0x01. 3. Follow steps 3 through 10 of the startup sequence on page 34 of the LTC2000 data sheet. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 1 Linear Technology Corporation er2000fa LT 0416 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015