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