LM629: What is the connection between LM629's PID output and LM629's PWM output?

Hi user5351218,

For the LM629, the control output signal appears to be a signed value. The sign should appear on the PWM Sign output, and the magnitude should appear as a PWM frequency on the PWM Mag pin.

This is consistent with the LM628 DAC output port, as described in "Motor Outputs" section, where values less than 80hex is negative torque and values greater than 80hex is positive torque.

The LM628 DAC output port can be configured to provide either a latched eight-bit parallel output or a
multiplexed 12-bit output. The 8-bit output can be directly connected to a flow-through (non-input-latching) D/A
converter; the 12-bit output can be easily demultiplexed using an external 6-bit latch and an input-latching 12-bit
D/A converter. The DAC output data is offset-binary coded; the 8-bit code for zero is 80 hex and the 12-bit code
for zero is 800 hex. Values less than these cause a negative torque to be applied to the motor and, conversely,
larger values cause positive motor torque. The LM628, when configured for 12-bit output, provides signals which
control the demultiplexing process.

Sorry to continue bother you.
I‘ using LM629 's velocity mode mode to drive a motor to maintain a certain speed.Incremental encoder was used to gain the speed of motor.
So I was wondering,is the PID's output directly becomes the PWM's singal,and when the motor's speed beyond the speed I set,PID's output becomes a minus number,the PWM sign signal reverse?
Or the PWM singal is the sum of every sampling cycle's PID output,when the PID output becomes a minus number,PWM's duty cycle will reduce bit by bit,and when the PID output becomes a positive number,the PWM's duty cycle increase bit by bit?
I'm only consider the velocity mode.