Datasheet

( )
MON J JT
10mV
(T ) = 0.47 V + T
°C
200
175
150
125
100
75
50
25
0
0 1 2 3 4 5 6 7 8 9 10
I (A)
OUT
DI=4 A
ΔI
2
ΔI
2
ì ü
ï ï
ï ï
í ý
ï ï
ï ï
î þ
³
D
D
OUT OUT
MON OUT
OUT OUT
μA
20 I If I
A
I (I , I) =
μA μA
10 I + 5 I If I <
A A
UCD7242
SLUS962B –JANUARY 2010–REVISED AUGUST 2012 www.ti.com
IMON
MOSFET current sense monitor output. This pin provides a current source output that is proportional to the
current flowing in the power MOSFETs. The gain on this pin is equal to 20μA/A. The I
MON
pin should be
connected to a resistor to GND to produce a voltage proportional to the power-stage load current. For example, a
value of 10kΩ to ground produces a voltage of 2.0V when the power stage current is 10A.The accuracy of the
reported current is a function of the peak to peak ripple current in the inductor (ΔI). The nominal behavior is
described by Equation 1. The plot illustrates the possible variability in the sensed current as a function of load for
a ΔI=4A. If no PWM is detected for 8µs IMON will report 0V.
(1)
Figure 14. Sensed Current Variability
TMON
The voltage on this pin is proportional to the die temperature with a gain of 10 mV/°C and an offset voltage of
0.47 V at T
J
= 0°C (Equation 2):
(2)
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