Analog Devices MAX22204 Product Info

• Two H-Bridges with +65V Voltage Rating
  • Total Rdson (High-Side + Low-Side): 300mΩ Typical (T_A = 25°C)
• Current Ratings per H-Bridge (Typical at T_A = 25°C):
  • I_MAX = 8A_MAX (Impulsive Current for Driving Capacitive Loads)
  • I_FS(MAX) = 8A (Maximum Full Scale Current Setting for Internal Current Drive Regulation)
  • I_RMS = 2A_RMS per Phase (T_A = 25°C, V_M = +24V)
• Integrated Current Control
  • Full-Scale DAC Current Configurable with External Resistance
  • One Logic Input (TRQ) to Quickly Change the Torque among Two Levels
  • Internal Current Sensing (ICS) Eliminates External Bulky Resistors and Improves Efficiency
  • Built-in-Control with 128-usteps Indexer
    • STEP/DIR Interface
    • Integrated DAC and Sequencer for U-Stepping
  • Multiple Decay Modes (Slow, Mixed, Adaptive)
  • Fixed OFF Time Configurable with External Resistance
• Current-Sense Output (ISENA, ISENB) Current Monitor
• Fault Indicator Pin (FAULT)
• Protections
  • Overcurrent Protection for each Individual Channel (OCP)
  • Undervoltage Lockout (UVLO)
  • Thermal Shutdown T_J = 155°C (TSD)
• Available in TQFN38 5mm x 7mm and TSSOP38 9.7mm x 4.4mm Packages

The MAX22204 is a two-phase stepper motor driver. It integrates two 65V, 3.8A_MAX H-Bridges. The H-Bridge FETs have very low impedance, resulting in high driving efficiency and minimal heat. The typical total R_ON (high- side + low-side) is 0.3Ω. The MAX22204 integrates an accurate current drive regulation circuit and a 128-microstep built-in indexer controlled by a STEP/DIR interface. The high microstep resolution and advanced control technique ensure smooth and quiet operations.

The current flowing into the two low-side FETs is sensed by a non-dissipative Integrated Current Sensing (ICS) and it is then compared with the desired step threshold current. As soon as the bridge current exceeds the threshold (I_TRIP), the device enforces the decay for a fixed OFF-time (t_OFF).

The non-dissipative ICS eliminates the bulky external power resistors normally required for this function, resulting in a dramatic space and power saving compared with mainstream applications based on the external sense resistor. Currents proportional to the internally-sensed bridge currents are output to pins ISENA and ISENB. By connecting external resistors to these pins, voltages proportional to the bridge currents are generated. These can be used for diagnostic purposes.

The maximum output current per H-Bridge is I_MAX = 3.8A_MAX limited by the Overcurrent Protection (OCP). The device delivers up to 2A_RMS per phase at V_M = +24V and T_A = 25°C with proper PCB ground plane for thermal dissipation. The current capability depends on the PCB thermal characteristic (PCB ground planes, heatsinks, ventilation, etc.). The maximum full-scale current per H-Bridge is I_FS = 2.8A and can be set by an external resistor connected from the REF pin to GND. This current is defined as the maximum current setting of the integrated drive regulati