A5974ADTR STMicroelectronics, A5974ADTR Datasheet - Page 28

• Manufacturer Part Number: A5974ADTR
• Description: IC REG SW STEP-DOWN 2A 8SOIC
• Manufacturer: STMicroelectronics
• Series: -r
• Type: Step-Down (Buck), PWMr

Specifications of A5974ADTR

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.235 V ~ 35 V
• Current - Output: 2A
• 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: 497-11423-2

Application information
28/49
where T
switching losses when driving an inductive load (see
switching time.
Figure 14. Switching losses
●
Equation 25
where I
Example:
R
150 °C. We can consider a value of 0.4 Ω.
T
I
The overall losses are:
Equation 26
The junction temperature of the device is:
Equation 27
Q
SW
DS(on)
has a typical value of 5 mA @ V
Quiescent current losses.
–
–
–
is approximately 70 ns.
Q
has a typical value of 0.25 @ 25 °C and increases up to a maximum value of 0.5. @
RISE
is the quiescent current.
V
V
I
OUT
OUT
IN
and T
= 12 V
= 2A
= 3.3 V
=
P
TOT
0.4 2
FALL
⋅
=
2
represent the switching times of the power element that cause the
R
⋅
DSON
0.3
+
Doc ID 018762 Rev 1
⋅
12 2 70 10
(
I
OUT
⋅
T
IN
J
⋅
=
)
= 12 V.
2
P
T
⋅
Q
⋅
D
A
=
+
+
–
R
V
V
9
thJA
IN
IN
⋅
500 10
⋅
⋅
I
I
⋅
Q
OUT
P
⋅
TOT
Figure
⋅
3
T
+
SW
12 5 10
⋅
⋅
F
14). T
SW
⋅
+
–
SW
V
3
IN
≅
is the equivalent
1.38W
⋅
I
Q
=
A5974AD