A5975ADTR STMicroelectronics, A5975ADTR Datasheet - Page 32

• Manufacturer Part Number: A5975ADTR
• Description: IC REG SW STEP-DOWN 2.5A 8SOIC
• Manufacturer: STMicroelectronics
• Series: -r
• Type: Step-Down (Buck), PWMr

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

Application information
8.4
8.5
32/50
RMS current of the embedded power MOSFET
As the A5975AD embeds the high side switch, the internal power dissipation is sometimes
the bottleneck for the output current capability (refer to
operating temperature).
Nevertheless, as mentioned in the general description
continuous output current of 2.5 A in most of the application conditions.
However, the rated maximum RMS current of the power elements is 2 A, where:
and the real duty cycle is D:
Fixing the limit of 2 A for I
in
Figure 18. Maximum continuous output current vs. duty cycle
Short-circuit protection
In overcurrent protection mode, when the peak current reaches the current limit, the device
reduces the T
frequency to approximately one third of its nominal value even when synchronized to an
external signal (see
in most applications, this is enough to limit the current to I
short-circuit at the output (V
and parasitic effect of external components), the current peak could reach values higher
than I
Figure
LIM
.
18.
ON
down to its minimum value (approximately 250 nsec) and the switching
Section
RMS HS
D
O
5.4). In these conditions, the duty cycle is strongly reduced and,
=
= 0 V) and depending on the application conditions (V
Doc ID 018761 Rev 1
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V
V
, the maximum output current can be derived, as illustrated
IN
OUT
+
I
(
RMS HS
R
+
DS(on) LS
(
R
DS(on) LS
=
I
LOAD
–
R
+
DS(on) HS
DCR
⋅
D
on page
Section 8.3
) I
LIM
⋅
) I
⋅
LOAD
. In any event, in case of heavy
LOAD
1, the device can manage a
for an estimation of the
A5975AD
CC
value