C28x core at 40 MHz — real-time control headroom
The TMS320F28021DAS runs a 32-bit C28x core at 40 MHz, giving you about 40 MIPS for the control loop before the interrupt latency eats into the PWM update window. For a 10 kHz current loop, that leaves roughly 4000 cycles per iteration — enough for a PID with feedforward and a Clarke/Park transform without hand-optimising in assembly. On-chip flash is 64 KB (32K x 16), and the RAM is 5K x 16 — the RAM split is the thing to watch: the bootloader and stack carve into that 5K, so a control application with three 1 KB data arrays is already at 60% RAM utilisation before the stack frames. Plan the linker map early.
Peripheral set for motor and power conversion
Seven 12-bit ADC channels are enough to sample three phase currents, the DC bus voltage, and one temperature sensor with a channel to spare for a spare or a second temperature point. The ADC samples at up to 4.6 MSPS in single-sequencer mode, so a 10 kHz current loop with three phases sampled sequentially fits within 1 µs of the PWM cycle. The PWM module on this Piccolo part has the standard C200x timer-compare unit — it generates complementary pairs with dead-band insertion, so you can drive a three-phase inverter directly without external dead-time logic. Connectivity covers I²C, SCI, and SPI — enough for an external EEPROM, a temperature sensor, or a serial LCD. No CAN on this package, so if the application needs a CAN bus, the F2800132PTR peer is the one to look at.
38-TSSOP and the board-level fit
The 38-TSSOP package (0.240" body width, 6.10 mm) has a 0.65 mm pitch — a two-layer board can route the peripheral signals out, but the decoupling caps need to sit within 3 mm of each VDD pin pair to keep the 1.71–1.995 V core rail clean. The supplier device package is the same 38-TSSOP, so no footprint ambiguity between the order code and the reel label. Operating temperature spans -40 to 125 °C, which puts it in the industrial-plus band — it lives in a motor drive enclosure or an engine-bay ECU without derating the clock speed.