Datasheet

V
CC2
V
C
V
OUT
V
EE-P
ISO5500
15 V
R
G
Q
G
15 V
r
on-max
r
off-max
( )
on-max off-max
OL-WC IN P G CC2 EE-P
on-max G off-max G
r r
P = 0.5 f Q V V +
r + R r + R
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ISO5500
www.ti.com SLLSE64C –SEPTEMBER 2011–REVISED JUNE 2013
DETERMINING THE MAXIMUM AVAILABLE, DYNAMIC OUTPUT POWER, P
OD-max
The ISO5500 total power consumption of P
D
= 592 mW consists of the total input power, P
ID
, the total output
power, P
OD
, and the output power under load, P
OL
:
P
D
= P
ID
+ P
OD
+ P
OL
(2)
With: P
ID
= V
CC1-max
× I
CC1-max
= 5.5 V × 8.5 mA = 47 mW, (3)
and: P
OD
= (V
CC2
– V
EE-P
) x I
CC2-q
= 30 V × 14 mA = 420 mW, (4)
then: P
OL
= P
D
– P
ID
– P
OD
= 592 mW – 47 mW – 420 mW = 125 mW. (5)
In comparison to P
OL
, the actual dynamic output power under worst case condition, P
OL-WC
, depends on a variety
of parameters:
(6)
Where
f
INP
= signal frequency at the control input V
IN(±)
Q
G
= power device gate charge
V
CC2
= positive output supply with respect to V
E
V
EE-P
= negative output supply with respect to V
E
r
on-max
= worst case output resistance in the on-state: 4Ω
r
off-max
= worst case output resistance in the off-state: 2.5Ω
R
G
= gate resistor
Once RG is determined, Equation 6 is to be used to verify whether P
OL-WC
< P
OL
. Figure 69 shows a simplified
output stage model for calculating P
OL-WC
.
Figure 69. Simplified Output Model for Calculating P
OL-WC
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