ZXLD1370_1103 DIODES [Diodes Incorporated], ZXLD1370_1103 Datasheet - Page 21

• Manufacturer Part Number: ZXLD1370_1103
• Description: 60V HIGH ACCURACY BUCK/BOOST/BUCK-BOOST LED DRIVER-CONTROLLER WITH AEC-Q100
• Manufacturer: DIODES [Diodes Incorporated]

Or in case of separate voltage supply, with V
ZXLD1370
Document number: DS32165 Rev. 4 - 2
Applications Information
Assuming that cumulatively the rise time and fall time can account for a maximum of 10% of the period, the maximum
frequency allowed in this condition is:
This frequency is within the recommended frequency range the device can handle, therefore the ZXMN6A09K is
recommended to be used with the ZXLD1370 for frequencies from 300kHz to 500kHz).
The recommended total gate charge for the MOSFET used in conjunction with the ZXLD1370 is less than 30nC.
Junction temperature estimation
Finally, the ZXLD1370 junction temperature can be estimated using the following equations:
Total supply current of ZXLD1370:
Power consumed by ZXLD1370
Where the total quiescent current IQ
discharge the gate of the power MOSFET. Moreover the part of thermal resistance between case and ambient depends on
the PCB characteristics.
t
I
Where I
P
P
T
PERIOD
QTOT
J
IC
IC
=
= V
= V
Figure 27. Power derating curve for ZXLD1370 mounted on test board according to JESD51
≈ I
IN
IN
= 20*dt
Q
Q
T
T
• (I
• I
= total quiescent current I
A
A
+ f • Q
Q-IN
+ P
+ P
Q
2.5
1.5
0.5
+ f • Qg)
2
1
0
IC
IC
+ V
-40
G
• θ
• (θ
aux
JA
JC
• (I
=
-25
+ θ
Q-AUX
f = 1/ t
CA)
(Continued)
TOT
-10
+ f • Qg)
PERIOD
consists of the static supply current (IQ) and the current required to charge and
AUX
Q-IN
5
< 15V
+ I
= 515kHz
Q-AUX
Ambient temperature (°C)
20
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ZXLD1370
March 2011