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LMK00804B-Q1: Output Drive Current Capability

Cedrick

Expert 8270 points

Part Number: LMK00804B-Q1
Other Parts Discussed in Thread: LMK00804

Hi,

Good day.

Our customer would like to know if there's a published specification for the output (Q0 - Q3) drive current capability of this device?

It is able to drive the standard LVCMOS terminations but they are looking to have a output series termination of 43 Ohms and load termination of 50 Ohms with a 40 MHz clock input.

Regards,

Cedrick

over 2 years ago

0 Julian Hagedorn over 2 years ago

TI__Mastermind 20900 points

Hi Cedrick,

the output swing will be VDD/2 in case of a 50 Ohm termination.

Regards,

Julian

0 Kia Rahbar over 2 years ago in reply to Julian Hagedorn

TI__Expert 8585 points

Hello Cedrick,

IOH = (VOH-VDDO/2) / 50

IOL = (VOL-VDDO/2) / 50.

For example, for a VDDO of 3.3 V:

IOH min = (2.64 - (3.3/2))/50 = 19.8 mA

IOL max = (0.66 - (3.3/2))/50 = -19.8 mA

The recommended LVCMOS output termination for the LMK00804 is as follows:

If a 50 ohm to GND is added, the swing will be reduced in half as Julian has stated.

Regards,

Kia Rahbar