STODD01 STMicroelectronics, STODD01 Datasheet - Page 23

• Manufacturer Part Number: STODD01
• Description: Monolithic power management for high definition ODD with true shut-down, reset, and programmable step-up voltage
• Manufacturer: STMicroelectronics

Specifications of STODD01

• Typical Efficiency: > 90 %
• Low Switching Quiescent Current: max 2.2 mA overtemperature range

STODD01
9.5
Equation 7
where Δ I
The output voltage ripple (V
Equation 8
where F
The use of ceramic capacitors with voltage ratings in the range higher than 1.5 times the
maximum input or output voltage is recommended.
Layout considerations
Due to the high switching frequency and peak current, the layout is an important design step
for all switching power supplies. Important parameters (efficiency, output voltage ripple,
switching noise immunity, etc.) can be affected if the PCB layout is not designed with close
attention to the following DC-DC general layout rules, such as:
●
●
●
●
Moreover, the exposed pad ground connection must be properly designed in order to
facilitate the heat dissipation from the exposed pad to the ground layer using PCB vias, as
shown in the recommended PCB layout of
V
V
OUT
OUT
Short, wide traces must be implemented for mains current and for power ground paths.
The input capacitor must be placed as close as possible to the IC pins as well as the
inductor and output capacitor.
The feedback pin (FB) connection to the external resistor divider is a high impedance
node, so interference can be minimized by placing the routing of the feedback node as
far as possible from the high current paths. To reduce pick up noise the resistor divider
must be placed very close to the device.
A common ground node minimizes ground noise.
The exposed pad of the package must be connected to the common ground node.
_
_
RIPPLE
RIPPLE
SW
L
is the ripple current and F
=
is the switching frequency.
=
Δ
I
OUT
I
L
×
×
⎡
⎢
⎣
ESR
⎡
⎢
⎣
ESR
+
+
8
×
V
C
OUT
OUT_RIPPLE
OUT
(
V
1
Doc ID 17789 Rev 2
OUT
×
×
C
F
OUT
SW
−
V
SW
⎤
⎥
⎦
IN
×
F
)
), in continuous mode, for the step-up channel, is:
SW
is the switching frequency.
⎤
⎥
⎦
Figure
34, 35, and 36.
Application information
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