SETTLING

PHASE

TRACKING DOWN

(STEP DOWN)

PHASE

ISTEP_N+1

ISTEP_N

ON

FAST DECAY

SLOW DECAY

tON =

tON(MIN)

à FD +

10%

tON =

tON(MIN)

à FD +

10%

tON =

tON(MIN)

à FD +

10%

tON > tON(MIN)

à FD - 10%

tON > tON(MIN)

à FD - 10%

tON(FD) > tON(MIN)

KEEP FD = 10%

Figure 3. Adaptive Decay - Algorithm

Protections

Overcurrent Protection

Overcurrent protection protects the device against short circuits to the rails (supply voltage and ground) and between the

outputs (OUT1_ and OUT2_). The OCP threshold is set at 3.8A minimum. If the output current is greater than the OCP

threshold for longer than the Overcurrent Protection Blanking Time (tOCP), then an OCP event is detected.

When an OCP event is detected, the H-bridge is immediately disabled, and a fault indication is output on pin FAULT.

The H-bridge is kept in HiZ mode for 3ms (see tRETRY specification). After that, the H-bridge is re-enabled according to

the current state of the inputs. If the short circuit is still present, this cycle repeats otherwise normal operation resumes.

Prolonged operation in a short-circuit failure mode is not recommended. Prolonged OCP events can affect the device

reliability.

Thermal Shutdown Protection

If the die temperature exceeds 165°C (typical value), a fault indication is output on pin FAULT and the driver is three-

stated until the junction temperature drops below 145°C. After that, the driver is re-enabled.

Undervoltage Lockout Protection

The device features Undervoltage Lockout Protection. The UVLO on VM is set at 4.15V maximum. When a UVLO event

occurs, a fault indication is output on pin FAULT and driver outputs are tristated. Normal operation resumes (and the

FAULT pin deasserts) as soon as the supply voltages are back in the nominal operating range.

MAX22210

36V, 3.8A Stepper Motor Driver

with Integrated Current Sense

and 128 Microstep Indexer

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