Hi Lee,
"Why are IN 2 and OUT2 different??"
When IN1 is set to a logic 0, the outputs are disabled. Current that was flowing through the FETs now flows through the body diodes of the DRV8837.
To maintain current flow OUT1 goes below ground…
Tom, thank you for the layout and schematic.
What is the "current-COM1" net? The GND pin and Thermal Pad of the device should be directly connected to GND. This is important for voltage levels and thermal dissipation.
You could also order a …
Other Parts Discussed in Thread: DRV8837EVM , DRV8837 Connected Launchpad MSP430G2 to DRV8837EVM to test PWM. Current running through IN1 and IN2 when power is applied via USB or 3V to J1. Reproduce: Connect DRV8837EVM IN1 and GND to Launchpad MSP430G2 P1…
Other Parts Discussed in Thread: DRV8837 , DRV8837EVM Working to understand INx PWM interface on DRV8837. 3V to VM and GND. Hooked up Launchpad MSP430G2 P1.6 to DRV8837EVM IN1. Set max PWM frequency to 250 kHz. Shouldn't the motor rotate clockwise? I'm…
Hi Ryan,
Thanks for your reply. Our customers' EE is toothbrush. The space of PCB is limited. They have made their DRV8837EVM and plan to test.
Here is their schematic. They use M_PWM1 to control both DRV8837. Will it still have the risk of shoot…
Hi Ryan,
With regards to the DRV8837C, I think the Rds has an additional role to play as well. The issue here is not only with the fast rise time but the fast charging of the coil, and I believe, the 8837C does not charge the coil as fast as the 8837…
Gordon,
Please see the following video:
https://training.ti.com/motor-interfaces-and-pwm-frequencies
Also, in section 7.3 of the datasheet there is a truth table. I would recommend operating the motor in either a drive state (CW or CCW) or a BRAKE state…
no i am not using msp fet ,i am tried to to use USB cable to debugging i have only that option.
i am using only msp430g2131 board to debugging,not G2553.
custom board am not using in this case ,
i am using DRV8837evm .
after connecting the DRV8837evm…
Hi Vladislavas,
It was confirmed that there is an issue with the spice model that is causing the spikes to appear at the output. Unfortunately, this is a problem that will not be able to be fixed at this moment.
If you want to test and evaluate the DRV8837…
ear Pablo,
thanks for your reply. from drv8837 datasheet, in brake mode , both input1 and input2 should be high. but in complementary pwm mode ,i think that if input 1 is high, then input 2 should be low, vice versa. if it is this case ,i don't think…
