General Description

The MAX22211 is a dual 36V, 3.8AMAX H-bridge. It can

be used to drive two brushed DC motors or a single stepper

motor. The H-bridge FETs have very low impedance

resulting in high driving efficiency and low heat generation.

The typical total RON (high-side + low-side) is 0.25Ω.

Each H-bridge can be individually pulse-width modulation

(PWM)-controlled using three logic inputs (DIN1, DIN2,

EN).

The MAX22211 features an accurate current drive regulation

(CDR) which can be used to limit the start-up current

of a brushed DC motor or to control the phase current for

stepper operation. The bridge output current is sensed by

a non-dissipative integrated current sensing (ICS) and it

is then compared with user configurable threshold (ITRIP).

When the bridge current exceeds the ITRIP threshold, the

device enforces the decay for a fixed OFF-time (tOFF).

Four different Decay methods are supported (Slow Decay,

Fast Decay, and two Mixed Decay modes). The non-dissipative

ICS eliminates bulky external power resistors which

are normally required for this function resulting in a dramatic

space and power saving compared with mainstream

applications using external sense resistors.

The internally measured current of the two full bridges are

mirrored on pins ISENA and ISENB. By connecting external

resistors to these pins to GND, voltages proportional

to the motor currents are generated. The voltage across

these external resistors can be used as inputs to analogto-

digital converters (ADCs) of an external motor controller

if the motion control algorithm requires the load current or

torque information.

In addition, two open-drain output pins (CDRA, CDRB) are

asserted every time the internal current regulation takes

control of the driver. This allows the external controller to

monitor the activity of the internal current loop.

The maximum user configurable current regulation threshold

(ITRIP_MAX) can be set up to 3.8A and is limited by the

Overcurrent Protection (OCP). The ITRIP current thresholds

can be set independently for the two full bridges by

connecting external resistors from pins REFA and REFB

to GND. Because of thermal considerations, the recommended

maximum RMS current for standard four-layer

PCBs is 2ARMS per H-bridge.

The MAX22211 features OCP, thermal shutdown (TSD),

and undervoltage lockout (UVLO) protection. An opendrain

active low FAULT pin is activated every time a fault

condition is detected. During TSD and UVLO events, the

driver is three-stated until normal operations are restored.

The MAX22211 is available in a small TQFN32 5mm x

5mm package or a TSSOP28 4.4mm x 9.7mm package.

Benefits and Features

● Two H-Bridges with +36V Maximum Operating

Voltage

• Total RON (High-Side + Low-Side): 250mΩ Typical

(TA = 25°C)

● Current Ratings per H-Bridge (Typical at TA = 25°C)

• ITRIP_MAX = 3.8A (Maximum Current Setting for

Internal Current Drive Regulation)

• IRMS = 2ARMS (Recommended Maximum RMS

Current per Full Bridge)

● Integrated Current Drive Regulation

• ICS Eliminates Bulky External Resistors and

Improves Efficiency

• Current Drive Regulation Monitor Output Pins

(CDRA, CDRB)

• Four Decay Modes Supported (Slow Decay, Fast

Decay, and two Mixed Decays)

• Half Full Scale (HFS) Pin to Improve Current

Control Accuracy in the Low Current Range

● Current Sense Output (Current Monitor)

● Fault Indicator Pin (FAULT)

● Low-Power Mode (Sleep Mode)

● Protections

• OCP for Each Individual Channel

• UVLO

• TSD TJ = 165°C

● TQFN32 5mm x 5mm Package and TSSOP28 4.4mm x 9.7mm Package

Applications

● Stepper-Motor Driver

● Brushed DC Motor Driver

● Solenoid Driver

● Latched Valves