US 7,345,516 B2
Apparatus and method for adjusting slew rate in semiconductor memory device
Jae-Hyuk Im, Ichon-shi (Korea, Republic of); and Kee-Teok Park, Ichon-shi (Korea, Republic of)
Assigned to Hynix Semiconductor, Inc., Kyongki-Do (Korea, Republic of)
Filed on Dec. 28, 2004, as Appl. No. 11/22,840.
Claims priority of application No. 10-2004-0026252 (KR), filed on Apr. 16, 2004.
Prior Publication US 2005/0231251 A1, Oct. 20, 2005
Int. Cl. H03K 5/12 (2006.01)
U.S. Cl. 327—170  [326/86; 326/87] 20 Claims
OG exemplary drawing
 
1. A slew-rate adjusting apparatus for use in a semiconductor memory device, comprising:
a slew-rate modulation signal generator for generating slew-rate modulation signals according to a data signal and the number of control codes, wherein the slew-rate modulation signal generator includes a logic combination unit for combining logic levels of the control codes to output control signals and a switching unit for receiving the data signal and the control signals to generate the slew-rate modulation signals used to adjust a number of switching elements; and
a pre-driver for adjusting a slew rate of an output by changing the number of the switching elements turned on by the slew-rate modulation signals and the data signal.