Analog Devices MAX22210 Product Info

• Total R_DS(ON) (HS + LS): 250mΩ at TA = +25°C (typ)

• I_MAX = 8A_MAX (Impulsive Current for Driving Small Capacitive Loads)
• I_FS = 3A_MAX (Full-Scale Current Setting for Internal Current-Drive Regulation)
• I_RMS = 2A_RMS

• Full-Scale Current Configurable with External Resistance
• One Logic Input (HFS) to Improve Current-Control Accuracy for Low Current Values
• Internal Current Sensing (ICS) Eliminates External Bulky Resistors and Improves Efficiency
• Built-In Control with 128 Microstep Indexer
  • STEP/DIR Interface
  • Integrated DAC and Lookup Table for Microstepping
• Multiple Decay Modes (Slow, Mixed, Adaptive)
• Configurable PWM OFF Time with External Resistance

• Overcurrent Protection (OCP) for Each Power FET
• UVLO
• Thermal Shutdown (TSD) T_J = +165°C

The MAX22210 is a 2-phase stepper motor driver. It inte- grates two 36V, 3.8A_MAX H-bridges.

The H-bridge FETs have very low impedance that result in high driving efficiency and minimal heat generated. The typical total R_ON (high side + low side) is 0.25Ω.

The MAX22210 integrates an accurate current drive reg- ulation circuit and a 128-microstep built-in indexer controlled by a STEP/DIR interface. The high microstepping resolution and advanced control technique ensure smooth and quiet operation.

The current flowing into the two low-side FETs is sensed by a nondissipative integrated current sensing (ICS) and it is then compared with the desired step threshold current. As soon as the bridge current exceeds the setpoint (I_TRIP), the device enforces decay for a fixed OFF time (T_OFF). Three decay modes are supported: slow, mixed, and adaptive.

The nondissipative integrated current sensing eliminates the bulky external power resistors that are normally re- quired for this function resulting in a dramatic space and power saving compared with mainstream applications based on external sense resistors.

The internally sensed phase currents are mirrored on two pins (ISENA, ISENB) to allow the external controller to keep monitoring the currents and can use this information for diagnostic purposes.

The maximum output current per H-bridge is I_MAX = 3.8A_MAX, which is limited by the overcurrent protection (OCP).

The maximum RMS current per H-bridge is I_RMS = 2A_RMS at room temperature, assuming a 4-layer PCB. Since this current is limited by thermal considerations, the actual maximum RMS current depends on the thermal charac- teristic of the application such as PCB ground planes, heatsinks, ventilation, etc.

The maximum full-scale current per H-bridge is I_FS = 3A that can be