STLC3055N STMicroelectronics, STLC3055N Datasheet - Page 16

• Manufacturer Part Number: STLC3055N
• Manufacturer: STMicroelectronics

Specifications of STLC3055N

• Number Of Channels: 1
• On-hook Transmission: Yes
• Polarity Reversal: Yes
• On-chip Ring Relay Driver: No
• Longitudinal Balanced: 58
• Operating Supply Voltage (typ): 9V
• Operating Temp Range: -40C to 85C
• Package Type: TQFP
• Loop Current Limit: 40mA
• Operating Temperature Classification: Industrial
• Pin Count: 44
• Mounting: Surface Mount
• Operating Current: 55mA
• Operating Supply Voltage (max): 12V
• Operating Supply Voltage (min): 5.5V
• Lead Free Status / RoHS Status: Not Compliant

Application information
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5.1
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Application information
Layout recommendation
A properly designed PCB layout is a basic issue to guarantee a correct behavior and good
noise performances. Noise sources can be identified in not enough good grounds, not
enough low impedance supplies and parasitic coupling between PCB tracks and high
impedance pins of the device.
Particular care must be taken on the ground connection and in this case the star
configuration allows surely to avoid possible problems (see
Figure 9 on page
The ground of the power supply (VPOS) has to be connected to the center of the star, let’s
call this point Supply GND. This point should show a resistance as low as possible, that
means it should be a ground plane.
In particular to avoid noise problems the layout should prevent any coupling between the
DC/DC converter components that are referred to PGND (CVPOS, CD, L) and analog pins
that are referred to AGND (ex: RD, IREF, RTH, RLIM, VF). AGND and BGND must be
shorter together. The GND connection of protection components have to be connected to
the Supply GDND.
As a first recommendation the components CV, L, D1, CVPOS, RSENSE should be kept as
close as possible to each other and isolated from the other components.
Additional improvements can be obtained:
●
●
decoupling the center of the star from the analog ground of STLC3055N using small
chokes.
adding a capacitor in the range of 100 nF between VPOS and AGND in order to filter
the switch frequency on VPOS.
21).
Figure 8 on page 20
STLC3055N
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