AM2170

Motor Driver ICs

A

s

O

2

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the maximum level (see table). The 0% output current condition turns OFF all drivers in the bridge and can be used as

an OUTPUT DISABLE function.

Current – Control Truth Table

Output Current

L

L

H

L

L

H

H

H

0

These logic level inputs greatly enhance the implementation of μP-controlled drive formats.

in an eight-step sequence. This is a accomplished by digitally selecting 100% drive current when only one phase is

current decay when switching phases. This helps to ensure proper motor operation at high step rates.

The logic control inputs can also be used to select a reduced current level (and reduced power dissipation) for ‘hold’

conditions and/or increased current (and available torque) for start-up conditions.

The PHASE input to each bridge determines the direction of current flow in the motor winding. An internally

generated deadtime (approximately 2μs) prevents crossover currents that can occur when switching the PHASE input.

decay through the internal output clamp and flyback diodes. The fast current decay is desirable in half-step and

high-speed applications. All inputs float high.

applications and DC motor control.

Thermal protection circuitry turns OFF all drivers when the junction temperature reaches +170℃. It is only intended

to protect the device from failures due to excessive junction temperature and should not imply that output short

circuits are permitted. The output drivers are re-enabled when the junction temperature cools to +145℃.

The AM2170 output drivers are optimized for low output saturation voltages – less than 1.8V total (source plus sink)

at 500mA. Under normal operating conditions, when combined with the excellent thermal properties of the batwing

packing design, this allows continuous operation of both bridges simultaneously at 500mA.