General Description
The MAX22210 is a 2-phase stepper motor driver. It integrates
two 36V, 3.8AMAX H-bridges.
The H-bridge FETs have very low impedance that result
in high driving efficiency and minimal heat generated. The
typical total RON (high side + low side) is 0.25Ω.
The MAX22210 integrates an accurate current drive regulation
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
(ITRIP), the device enforces decay for a fixed OFF time
(TOFF). Three decay modes are supported: slow, mixed,
and adaptive.
The nondissipative integrated current sensing eliminates
the bulky external power resistors that are normally required
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 IMAX =
3.8AMAX, which is limited by the overcurrent protection
(OCP).
The maximum RMS current per H-bridge is IRMS = 2ARMS
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 characteristic
of the application such as PCB ground planes,
heatsinks, ventilation, etc.
The maximum full-scale current per H-bridge is IFS = 3A
that can be set by an external resistor connected to IREF.
This current is defined as the maximum current setting of
the embedded current drive regulation circuit.
In applications where the maximum full-scale current is
less than 1.5A and high-current control accuracy is desired,
the half full scale (HFS) logic input pin can be set
high to halve the current ratings and double the low-side
FET RON. This results in better current control accuracy
especially for values close to the lower boundary of the
current range.
The MAX22210 features overcurrent protection, thermal
shutdown (TSD), undervoltage lockout (UVLO). An opendrain,
active-low FAULT pin is activated every time a fault
condition is detected.
During thermal shutdown and UVLO events, the driver is
disabled until normal operations are restored.
The MAX22210 is available in small, 5mm x 5mm
TQFN32 and 4.4mm x 9.7mm TSSOP28 packages.

Benefits and Features
● Two H-Bridges with 36V Rating
• Total RDS(ON) (HS + LS): 250mΩ at TA = +25°C
(typ)
● Current Ratings per H-Bridge (TA = +25°C, typ)
• IMAX = 3.8AMAX (Impulsive Current for Driving
Small Capacitive Loads)
• IFS = 3AMAX (Full-Scale Current Setting for Internal
Current-Drive Regulation)
• IRMS = 2ARMS
● Integrated Current Control
• 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
● Current-Sense Output (Current Monitor) (ISENA,
ISENB)
● Fault Indicator Pin (FAULT)
● Protections
• Overcurrent Protection (OCP) for Each Power FET
• UVLO
• Thermal Shutdown (TSD) TJ = +165°C
● Available in 5mm x 5mm TQFN32 and 4.4mm x
9.7mm TSSOP28 Packages

Applications
● Stepper Motor Drivers