IBIS Macromodel Task Group Meeting date: 15 October 2024 Members (asterisk for those attending): Achronix Semiconductor: Hansel Dsilva Altair: Junesang Lee Amazon: John Yan ANSYS: * Curtis Clark * Wei-hsing Huang Aurora System: Dian Yang Raj Raghuram Cadence Design Systems: * Ambrish Varma Jared James Dassault Systemes: Longfei Bai Google: Hanfeng Wang GaWon Kim Intel: Michael Mirmak [Kinger Cai] * Chi-te Chen Liwei Zhao Alaeddin Aydiner Sai Zhou Keysight Technologies: * Fangyi Rao Majid Ahadi Dolatsara Stephen Slater Ming Yan Rui Yang Marvell: Steve Parker Mathworks (SiSoft): * Walter Katz Graham Kus Micron Technology: Justin Butterfield Missouri S&T: Chulsoon Hwang Yifan Ding Zhiping Yang Rivos: Yansheng Wang SAE ITC: Michael McNair Samsung: Jun-Bae Kim Siemens EDA (Mentor): * Arpad Muranyi * Randy Wolff Signal Edge Solutions * Benjamin Dannan Teraspeed Labs: [Bob Ross] Zuken USA: Lance Wang The meeting was led by Arpad Muranyi. Curtis Clark took the minutes. -------------------------------------------------------------------------------- Opens: - None. ------------- Review of ARs: Yifan: Perform additional investigations into the applicability of BIRD220.1 for devices with independent pre-driver stages. - In progress. Arpad noted that Yifan had created a new draft of BIRD220.1, and he had sent it out with the ATM agenda email. He said Yifan had reported that she was still working on the additional investigations of devices with independent pre-driver stages. Michael: Prepare a new draft BIRD updating the language surrounding Ts4file and Ramp and related cross checking. - In progress. -------------------------- Call for patent disclosure: - None. ------------------------- Review of Meeting Minutes: Arpad asked for any comments or corrections to the minutes of the October 8th meeting. Ambrish moved to approve the minutes. Arpad seconded the motion. There were no objections. -------------- New Discussion: BIRD220.1 update: Arpad encouraged everyone to review Yifan's new (version 7) draft of BIRD220.1. Randy asked to review some of the slides from Yifan's presentation at the ATM meeting on September 10th. Arpad shared the slides, which Yifan had sent to the ATM list after the meeting on September 10th. Randy reviewed slides 8, 9, and 10, which show the gate_p, gate_n, and pad waveforms when driving into 50 Ohms to Vcc, 50 Ohms to GND, and 20pF to GND respectively. He noted that for the two resistive loads (slides 8 and 9) the gate waveforms were essentially identical, but the gate waveforms changed appreciably for the capacitive load (slide 10). Randy said he did not expect to see the change in gate waveforms for the capacitive load. He said that that the only connection to the test load would be through the gate to source or gate to drain capacitance. Fangyi asked about the pad waveforms in slide 8 (50 Ohms to Vcc). He found it odd that the output waveforms at the pad did not diverge until near saturation at the top of their range. The rising edges appeared identical until the values diverged at the top of the range. The group reviewed the test setup information, and Arpad suggested that this behavior likely resulted from the load being 50 Ohms to Vcc nominal, while the Vddq was swept. So, the resulting waveforms were similar to those seen in the "plateau" experiments when driving a load into Vddq/2. The rising edge was largely defined by the turnoff of the pulldown device, at which point the pad waveform was pulled to Vcc nominal by the test load. Once the pullup device turned on, the pad waveform was pulled toward the Vddq value. Randy agreed that this was the likely explanation, but he said that driving into a fixed Vcc nominal likely obscured the PSIJ effects the experiment was trying to demonstrate. Since V_fixture was nominal Vcc not Vddq, you have two different power supplies fighting each other. Randy and Arpad suggested that driving into Vddq or Vddq/2 would be more meaningful. Randy agreed to update Yifan on the discussion and ask her to redo the 50 Ohm to Vcc experiment into Vddq instead. Randy said he would also like to see a 4th column added to the slides to show the output waveforms for a power-aware IBIS [Model] driving into the same loads. - Curtis: Motion to adjourn. - Fangyi: Second. - Arpad: Thank you all for joining. New ARs: Randy: Update Yifan on the discussion in the meeting and ask her to redo the 50 Ohms to Vcc experiment into Vddq instead. ------------- Next meeting: 22 October 2024 12:00pm PT ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives