US6617891B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slew rate at buffers by isolating predriver from driver
Assignee: Intel Corp
•
Filing: 2001-09-26
•
Granted: 2003-09-09
•
Expires: 2021-09-26
Abstract
Abstract In one embodiment, a pre-driver generates pre-driving signals based on control signals provided by a control circuit. The pre-driver has pre-driver power and ground connections. The pre-driving signals operate at a frequency band. A driver generates an output signal based on the pre-driving signals at an output pad. The output signal has a slew rate. The driver has driver power and ground connections. A low pass filter is coupled between the pre-driver and the driver power and ground connections to reduce the effect of noise at the pre-driving signals. The low pass filter has a cut-off frequency corresponding to the frequency of noise. In another embodiment, a plurality of pre-drivers generates pre-driving signals based on control signals provided by a control circuit. The pre-drivers have pre-driver power and ground connections. A plurality of drivers generates a plurality of output signals based on the pre-driving signals at output pads of an integrated circuit. Each of the output signals has a slew rate. The drivers have driver power and ground connections. On-die pre-driver power and ground planes are coupled to the pre-driver power and ground connections on die of the integrated circuit, respectively. On-die driver power and ground planes are coupled to the driver power and ground connections on-die of the integrated circuit, respectively. The driver power and ground planes are separated from the pre-driver power and ground planes on the die, and/or on the package to maintain the desired slew rate.
Inventors
- 👤 Adhiveeraraghavan Srikanth
- 👤 Navneet Dour
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:34
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/16; H03K17/161; H03K17/162; H03K17/163
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
112 words
An apparatus comprising: a pre-driver coupled to a control circuit to generate pre-driving signals based on control signals provided by the control circuit, the pre-driver having pre-driver power and ground connections; a driver coupled to the pre-driver to generate an output signal based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections; and a low pass filter coupled between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connections connection to reduce noise at the pre-driver, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 2
Independent Claim
112 words
An apparatus comprising: a pre-driver coupled to a control circuit to generate pre-driving signals based on control signals provided by the control circuit, the pre-driver having pre-driver power and ground connections; a driver coupled to the pre-driver to generate an output signal based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections; and a low pass filter coupled between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connections connection to reduce noise at the pre-driver, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein the low pass filter maintains the slew rate.
Claim 4
Dependent Claim
66 words
The apparatus of claim 1 wherein the low pass filter comprises: a resistor connected between the pre-driver and driver power connections, the resistor having a resistance selected according to a pre-determined voltage drop and a current limit of the pre-driver; and a capacitor connected between the pre-driver power and ground connections, the capacitor having a capacitance selected according to the selected resistance and the cut-off frequency.
Claim 5
Dependent Claim
28 words
The apparatus of claim 1 further comprising: a ground resistor coupled between the pre-driver ground and the driver ground to isolate the pre-driver ground from the driver ground.
Claim 6
Dependent Claim
24 words
The apparatus of claim 4 wherein the ground resistor has a resistance selected according to a pre-determined voltage drop and a ground current limit.
Claim 7
Independent Claim
103 words
A method comprising: generating pre-driving signals using a pre-driver based on control signals provided by a control circuit, the pre-driver having pre-driver power and ground connections; generating an output signal using a driver based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections; and reducing noise at the pre-driving signals using a low pass filter placed between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connection, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 8
Independent Claim
103 words
A method comprising: generating pre-driving signals using a pre-driver based on control signals provided by a control circuit, the pre-driver having pre-driver power and ground connections; generating an output signal using a driver based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections; and reducing noise at the pre-driving signals using a low pass filter placed between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connection, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 9
Dependent Claim
14 words
The method of claim 6 wherein reducing the noise comprises maintaining the slew rate.
Claim 10
Dependent Claim
67 words
The method of claim 6 wherein reducing the noise comprises: providing a resistor connected between the pre-driver and driver power connections, the resistor having a resistance selected according to a pre-determined voltage drop and a current limit of the pre-driver; and providing a capacitor connected between the pre-driver power and ground connections, the capacitor having a capacitance selected according to the selected resistance and the cut-off frequency.
Claim 11
Dependent Claim
19 words
The method of claim 6 further comprising: isolating the pre-driver ground from the driver ground using a ground resistor.
Claim 12
Dependent Claim
24 words
The method of claim 9 wherein the ground resistor has a resistance selected according to a pre-determined voltage drop and a ground current limit.
Claim 13
Independent Claim
155 words
A device comprising: a package having package power and ground planes and output pins to interface to a board having board power and ground planes; an integrated circuit on a die coupled to the package, the integrated circuit having a buffer circuit, the buffer circuit comprising: a pre-driver coupled to a control circuit to generate pre-driving signals based on control signals provided by the control circuit, the pre-driver having pre-driver power and ground connections, a driver coupled to the pre-driver to generate an output signal based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections, and a low pass filter coupled between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connection to reduce noise at the pre-driving signals, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 14
Independent Claim
155 words
A device comprising: a package having package power and ground planes and output pins to interface to a board having board power and ground planes; an integrated circuit on a die coupled to the package, the integrated circuit having a buffer circuit, the buffer circuit comprising: a pre-driver coupled to a control circuit to generate pre-driving signals based on control signals provided by the control circuit, the pre-driver having pre-driver power and ground connections, a driver coupled to the pre-driver to generate an output signal based on the pre-driving signals at an output pad, the output signal having a slew rate, the driver having driver power and ground connections, and a low pass filter coupled between the pre-driver power connection and the driver power connection and between the pre-driver ground connection and the driver ground connection to reduce noise at the pre-driving signals, the low pass filter having a cut-off frequency corresponding to noise frequency.
Claim 15
Dependent Claim
14 words
The device of claim 11 wherein the low pass filter maintains the slew rate.
Claim 16
Dependent Claim
66 words
The device of claim 11 wherein the low pass filter comprises: a resistor connected between the pre-driver and driver power connections, the resistor having a resistance selected according to a pre-determined voltage drop and a current limit of the pre-driver; and a capacitor connected between the pre-driver power and ground connections, the capacitor having a capacitance selected according to the selected resistance and the cut-off frequency.
Claim 17
Dependent Claim
28 words
The device of claim 11 further comprising: a ground resistor coupled between the pre-driver ground and the driver ground to isolate the pre-driver ground from the driver ground.
Claim 18
Dependent Claim
24 words
The device of claim 14 wherein the ground resistor has a resistance selected according to a pre-determined voltage drop and a ground current limit.
References Cited (Backward Citations)
US4559507A
Cited
US4972436A
Cited
US5734285A
Cited
US5963057A
Cited
US5959492A
Cited
US6285214B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-09-08 | 2007-03-10 | 2007-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-09-08 | 2011-03-10 | 2011-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-09-08 | 2015-03-10 | 2015-09-09 | $7700.00 | Window Closed / Lapsed |