General Description

The MAX22208 provides four individually controllable 65V, 3.8AMAX half H-bridge drivers. It can be used to drive four solenoids, two brushed DC motors, one single stepper motor, or a combination of different loads.

The power FETs have very low impedance, resulting in high driving efficiency and low heat dissipation. The typical total RON (high side plus low side) is 0.3Ω (typ).

Each half bridge can be individually pulse-width modulation (PWM)-controlled with two logic inputs (DIN_, EN_).

The MAX22208 integrates non-dissipative current sensing, which 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.

A current proportional to the internally-sensed load current is output to the external current-monitor pins (ISEN_). By connecting an external resistor to these pins, a voltage proportional to the motor current is generated. The voltage drop across the external resistors can be input into the controller ADC whenever the control algorithm requires the current/torque information.

The maximum output current per half H-bridge is IMAX = 3.8A and is limited by the overcurrent protection (OCP) circuit. This current can be driven for very short transients and aims to effectively drive small capacitive loads.

The maximum RMS current per H-bridge is IRMS = 2A. Since this current is limited by thermal considerations, the actual maximum RMS current depends on the thermal characteristic of the application (PCB ground planes, heatsinks, forced air ventilation, etc.).

The MAX22208 features overcurrent protection (OCP), thermal shutdown (TSD), and undervoltage lockout (UVLO). An active-low, open-drain FAULT pin is activated every time a fault condition is detected.

During TSD and UVLO, the driver outputs are three-stated until normal operating conditions are restored.

The MAX22208 is available in a small, 5mm x 7mm, 38-pin TQFN and 4.4mm x 9.7mm, 38-pin TSSOP package.

Benefits and Features

● Four Independent Half H-Bridge Drivers

• 65V Maximum Operating Voltage

• 0.3Ω (typ) RON (High Side + Low Side) at TA = +25°C

• Fully Independent Half-Bridge Control

● Current Rating per H-Bridge (TA = +25°C):

• IMAX = 3.8A (Impulse Current for Driving Capacitive Loads)

• IRMS = 2A

● Integrated Current Sensing (ICS) Eliminates External Bulky Resistors and Improves Efficiency

● Current-Sense Output Monitor

● Fault Indicator Pin (FAULT)

• Overcurrent Protection for Each Individual Channel (OCP)

• Undervoltage Lockout (UVLO)

• Thermal Shutdown TSD = +155°C

● 5mm x 7mm, 38-Pin TQFN and 4.4mm x 9.7mm, 38-Pin TSSOP Packages

Applications

● Brushed DC Motor Driver

● Stepper Motor Driver

● Solenoid Driver

● Latched Valves