A5975ADTR STMicroelectronics, A5975ADTR Datasheet - Page 40
A5975ADTR
Manufacturer Part Number
A5975ADTR
Description
IC REG SW STEP-DOWN 2.5A 8SOIC
Manufacturer
STMicroelectronics
Series
-r
Type
Step-Down (Buck), PWMr
Datasheet
1.A5975ADTR.pdf
(50 pages)
Specifications of A5975ADTR
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.235 V ~ 35 V
Current - Output
2.5A
Frequency - Switching
500kHz
Voltage - Input
4 V ~ 36 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (0.154", 3.90mm Width) Exposed Pad
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
497-11425-2
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
A5975ADTR
Manufacturer:
ST
Quantity:
20 000
Application information
Figure 29. 350 mA LED boost current source
40/50
The device is powered from the output voltage so the maximum voltage drop across the
LEDs and resistor sense is 36 V.
The output voltage is given by:
Equation 42
where the ideal duty cycle D for the boost converter is:
Equation 43
As for positive and inverting buck-boost (see
real duty cycle must be used to calculate the switch current level.
The peak current flowing in the embedded switch is:
Equation 44
while its average current is equal to:
Equation 45
This is due to the fact that the current flowing through the internal power switch is delivered
to the output only during the OFF phase.
I
SW
=
Doc ID 018761 Rev 1
I
-------------- -
1 D
LOAD
–
+
D
V
I
------------------- -
I
RIPPLE
SW
OUT
=
2
V
----------------------------- -
=
OUT
Section 8.7
=
V
I
-------------- -
1 D
LOAD
OUT
------------ -
1 D
=
V
–
–
–
IN
I
-------------- -
V
1 D
LOAD
IN
–
+
and
---------- -
2 L
V
⋅
IN
Section
⋅
---------
f
SW
D
8.8.) the measured
A5975AD