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L8202

6

STEPPER MOTOR DRIVER OPERATIONS

Two H Bridges are provided to implement current control through the two widings of a Bipolar Stepper Mo-

tor.

The phase and current level information are programmed over the serial input port (see Serial Interface

Bits definition section).

Four current levels (0%,33%,66%,100%) are programmable through the status of IN0 and IN1 bits in the

Input Serial Port.

This drive enters the fast current decay mode when both the I0_PH_X and I1_PH_X inputs set to the high

logic level (current is recirculated from GND to Vs supply).

A blanking period following a current turn-on event is included to prevent false current protection.

The H Bridges are protected versus cross-conduction.

Thermal protection with hysteresys is provided to the Motor Drivers.

During thermal protection event the Bridge Outputs are forced into a high impedance status.

Table 14. Truth Table

Notes: 1. The 100% current is fixed by the sense resistor, and the Maximum Threshold of the Voltage Comparator

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Pulsed Output Current

1.5

A

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

ON Resistance

0.55

0.4

W

Comparator High Threshold

Voltage

I0_PH_x = 0

I1_PH_x = 0

500

mV

Comparator Medium Threshold

Voltage

I0_PH_x = 1

I1_PH_x = 0

333

mV

Comparator Low Threshold

Voltage

I0_PH_x = 0

I1_PH_x = 1

167

mV

VoOFF Output Leakage

Current for Stepper Motor

Driver Outputs

VoOFF = 5V

I0_PH_x = 1

I1_PH_x = 1

0.5

mA

Off time

20

30

40

µs

Thermal shutdown

140

°C

hysterisys)

Stepper Motor driver thermal

enable junction temperature

hysterisys

20

°C

I0_PH_x

I1_PH

L

L

100%

HL

66 %

LH

33 %

HH

0 %