Datasheet

31
621
UCD7242
V
IN
V
GG
Generator
V
GG
DIS
V
GG
Thermal
Sense
T
MON
22
BP3GND
32
25
18
26
BST-B
BSW-B
SW-B
12
10
11
PGND
I
MON
-B
FLT -B
SRE-B
PWM-B
8
Testmode
30
2
9
1
7
3
4
5
Current
Sense
Processor
20
28
29
27
19
Drive
Logic
13
Driver
Driver
V
IN
BST-A
BSW-A
SW-A
24
23
14
Driver
Driver
V
IN
V
DD
LDO
I
MON
-A
FLT -A
SRE-A
PWM-A
Current
Sense
Processor
Drive
Logic
V
IN
V
IN
V
IN
V
OUT
-AV
OUT
-B
Short
V
IN
15
16
PGND
17
UCD7242
SLUS962B –JANUARY 2010–REVISED AUGUST 2012 www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION (CONTINUED)
On-board comparators monitor the current through the high side switch to safeguard the power stage from
sudden high current loads. Blanking delay is set for the high side comparator to avoid false reports coincident
with switching edge noise. In the event of an over-current fault, the high-side FET is turned off and the Fault Flag
(FLT) is asserted to alert the controller.
MOSFET current is measured and monitored by a precision integrated current sense element. This method
provides an accuracy of ±5% over most of the load range. The amplified signal is available for use by the
controller on the I
MON
pin.
An on-chip temperature sense converts the die temperature to a voltage at the T
MON
pin for the controller’s use.
If the die temperature exceeds 170°C, the temperature sensor initiates a thermal shutdown that halts output
switching and sets the FLT flag. Normal operation resumes when the die temperature falls below the thermal
hysteresis band.
Figure 1. Typical Application Circuit and Block Diagram
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