33886 datasheet(17/25 Pages) FREESCALE

17 / 25 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33886

FUNCTIONAL DEVICE OPERATION

FUNCTIONAL PIN DESCRIPTION

FUNCTIONAL DEVICE OPERATION

SHORT CIRCUIT PROTECTION

If an output short circuit condition is detected, the power

outputs tri-state (latch-OFF) independent of the input (IN1

and IN2) states, and the fault status output flag is set logic

Low. If the D1 input changes from logic High to logic Low, or

if the D2 input changes from logic Low to logic High, the

output bridge will become operational again and the fault

status flag will be reset (cleared) to a logic High state.

The output stage will always switch into the mode defined

by the input pins (IN1, IN2, D1, and D2), provided the device

junction temperature is within the specified operating

temperature.

ACTIVE CURRENT LIMITING

The maximum current flow under normal operating

conditions is internally limited to ILIM (5.2 A to 7.8 A). When

the maximum current value is reached, the output stages are

tri-stated for a fixed time (ta) of 20 µs typical. Depending on

the time constant associated with the load characteristics, the

current decreases during the tri-state duration until the next

output ON cycle occurs (see Figures 9 and 12, page 9 and

page 10, respectively).

The current limiting threshold value is dependent upon the

device junction temperature. When -40

°C < T

J < 160°C, ILIM

is between 5.2 A and 7.8 A. When TJ exceeds 160°C, the ILIM

current decreases linearly down to 2.5 A typical at 175

°C.

Above 175

°C the device overtemperature circuit detects T

LIM

and overtemperature shutdown occurs (see Figure 7,

page 8). This feature allows the device to remain operational

for a longer time but at a regressing output performance level

at junction temperatures above 160

°C.

OVERTEMPERATURE SHUTDOWN AND

HYSTERESIS

If an overtemperature condition occurs, the power outputs

are tri-state (latched-OFF) independent of the input signals

and the fault status flag is set logic Low.

To reset from this condition, D1 must change from logic

High to logic Low, or D2 must change from logic Low to logic

High. When reset, the output stage switches ON again,

provided that the junction temperature is now below the

overtemperature threshold limit minus the hysteresis.

Note Resetting from the fault condition will clear the fault

status flag.

MAIN DIFFERENCES COMPARED TO

MC33186DH1

• COD pin has been removed. Pin 8 is now a Do Not

Connect (DNC) pin.

• Pin 20 is no longer connected in the 20 HSOP package. It

is now a DNC pin.

•RDS(ON) max at TJ = 150°C is now 225 mΩ per each output

transistor.

• Maximum temperature operation is now 160°C, as

minimum thermal shutdown temperature has increased.

• Current regulation limiting foldback is implemented above

160°C TJ.

• Thermal resistance junction to case has been increased

from ~2.0°C/W to ~5.0°C/W.

33886 Datasheet(PDF) 17 Page - Freescale Semiconductor, Inc

33886 Datasheet(HTML) 17 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Datasheet Download

Link URL