Datasheet


    
SLIS056A − FEBRUARY 1995 − REVISED MARCH 1996
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
PRINCIPLES OF OPERATION
over-temperature sensing
The TPIC2603 monitors the junction temperature of the die to detect over-temperature conditions which may
damage the device. When the junction temperature goes above approximately 170°C, the fault logic sets the
global over-temperature fault bit. An over-temperature fault is reported using the serial interface on bit 6 (for 8-bit
configuration) or bit 14 (for 16-bit configuration). The global over-temperature fault output in the serial data is
exclusively ORed with the second bit (bit 6 for 8-bit configuration or bit 14 for 16-bit configuration) of data input
to the SDI terminal. Bit 6 or bit 14 of the input data should be set low. Over-temperature faults are for
informational purposes only and do not affect the state of the drains. Figure 8 illustrates device operation under
over-temperature conditions.
160°C
170°C
Junction Temperature
Drains (Not Disabled)
Fault Bit
Figure 8. Over-Temperature Sense
PARAMETER MEASUREMENT INFORMATION
OUTPUT CURRENT
vs
TIME FOR INCREASING LOAD RESISTANCE
O
I − Output Current − A
I − Output Current − A
Region 1
Region 2
t
1
t
2
First output current pulses after turn-on in chopping mode with
resistive load.
0
3
O
0
t
1
≈ 55 µs
t
2
≈ 3.5 ms
t -Time
t - Time
REGION 1 CURRENT WAVEFORM
I
L
t
2
t
1
t
1
2
1
Region 3
T
C
= 25°C
NOTES: A. Region 1 − Analog current limit holds the maximum current while the device runs in chop mode.
B. Region 2 − Analog current limit is removed but device continues in chop mode.
C. Region 3 − Current is below chop mode sense; therefore, it is in normal operation. Variable load is resistance over time.
Figure 9. Chopping-Mode Characteristics