SLVSH22 May 2024 DRV8000-Q1
ADVANCE INFORMATION
The device features an output for current sensing, voltage node monitoring, and die temperature on the IPROPI pin. This information can be used for status or regulation of loads (on OUTx), check die temperature, or to provide local motor voltage. These integrated features eliminate the need for multiple external sense resistors or sense circuitry, reducing system size, cost and complexity.
The load currents are sensed by using a shunt-less high-side current mirror topology. The output is a fixed ratio of the instantaneous current of the enabled driver (OUTx). The signal at the output IPROPI is blanked for tIPROPI_BLKafter switching on the driver to allow time for the circuitry to settle. Bit IPROPI_SEL defines which of the outputs is multiplexed to the IPROPI pin, the control values shown in the table below:
IPROPI_SEL | Output |
---|---|
00000b | No output |
00001b | OUT1 Current Sense |
00010b | OUT2 Current Sense |
00011b | OUT3 Current Sense |
00100b | OUT4 Current Sense |
00101b | OUT5 Current Sense |
00110b | OUT6 Current Sense |
00111b | OUT7 Current Sense |
01000b | OUT8 Current Sense |
01001b | OUT9 Current Sense |
01010b | OUT10 Current Sense |
01011b | OUT11 Current Sense |
01100b | OUT12 Current Sense |
01101b | RSVD |
01110b | RSVD |
01111b | RSVD |
10000b | PVDD Output voltage |
10001b | Thermal Cluster 1 |
10010 | Thermal Cluster 2 |
10011 | Thermal Cluster 3 |
10100 | Thermal Cluster 4 |
Since the IPROPI pin is a multi-purpose pin which can also be used as second PWM pin control input option for half-bridges, the IPROPI/PWM2 pin mode is controlled with bit IPROPI_MODE in register IC_CTRL.
The diagram below shows the simple block diagram for the selectable IPROPI output:
For current output, the IPROPI output analog current is scaled by AIPROPI as follows:
For voltage output of PVDD, the voltage is scaled down by a factor of 32 from a range of 4.5V to 40V. The PVDD voltage output is as follows:
VIPROPI = VPVDD / 32For example:
The IPROPI output can also provide analog voltage representation of any single of the four thermal cluster temperature. This is intended for use in testing and evaluation, but not during device run-time.
For voltage conversion of thermal cluster temperature output reading, the voltage is scaled according to the temperature range -40°C to 185°C and output voltage range of 0V to 3V. The voltage read out :
VIPROPI = A + B*Cluster Temperaturewhere A is offset roughly equal to 980mV, and B is slope of 2mV/°C.
When the cluster temperature is -40°C, the IPROPI output voltage will be 980mV. At 185°C the IPROPI voltage will be 1.35V.
The IPROPI pin must be connected to an external resistor (RIPROPI) to ground in order to generate proportional voltage VIPROPI. This allows for the load current to be measured as a voltage-drop across the RIPROPI resistor in the application so that the full range of the controller ADC is utilized.
When the output is switched off, the current monitor output is in high impedance mode. The IPROPI output also has an optional sample and hold circuit that can be enabled with bit IPROPI_SH_EN in register HB_OUT_CNFG1.