MLX902xx Name of Sensor

Rev Y.X

22/Aug/98

Page 5

MLX10407

5-Channel Gauge Driver with Serial Link

MLX10407 5-Channel Gauge Driver with Serial Link

Page 5

Rev 1.1

28/Apr/01

Operation

1) 360° logometers

Immediately following a reset, the IC checks if there is any short-circuit or open circuit on each

buffer driver output (This test is not performed for outputs 5, 6 and 7). During this test, each buffer

is held in a high impedance state and large value internal resistors (100kOhm ) are sequentially

connected on each pair of buffers (note : actuator coils must be connected on bridges).

Three tests are performed according to the following figure and table.

Conditions

Test for :

Test 1

S1 closed, S2 open

V1 = VSS

Test 2

S1 open, S2 closed

V1 = VDD

Test 3

S1 and S2 closed

V1 = VDD/2

During the tests the pin ERRB (16) is at logic level 0. After completing the tests, ERRB remains

low if one (or more) test failed.

ERRB returns to high impedance if everything is OK.

These tests last approximately 4 ms with an oscillator clock frequency of 8 MHz.

After testing, all buffers are at VSS. The chip then waits for the MCU to send an angle/quadrant

value to output the PWM signals for each buffer. Every logometer coil is connected in a bridge,

so the current Icoil can be either positive or negative.

The total drop-out of a bridge is :

Test for short and open circuits

One Bridge