SC2440TETRT Semtech, SC2440TETRT Datasheet - Page 22

• Manufacturer Part Number: SC2440TETRT
• Description: IC SW REG DUAL 2.5MHZ 16-TSSOP
• Manufacturer: Semtech
• Type: Step-Down (Buck)r

Specifications of SC2440TETRT

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 2
• Current - Output: 2A
• Frequency - Switching: 1.4MHz
• Voltage - Input: 2.8 ~ 20 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Power - Output: -
• Other names: SC2440TETR

POWER MANAGEMENT
Applications Information
Figure 15.
2005 Semtech Corp.
V
IN
R1
R1
VOUT1
VOUT1
R2
R2
Figure 16.
L1
L1
Fast Switching Current Paths in a Buck
Regulator. Minimize the size of this loop
to reduce parasitic trace inductance.
D3
D3
R5
R5
C6
C6
C5
C5
C2
C2
D1
D1
C1
C1
R6
R6
Suggested PCB Layout for the SC2440. Notice that there is no via directly under
the device and that the only component on the backside is the frequency-setting
resistor. All vias are 12mil in diameter.
C7
C7
GND
GND
GND
GND
C15
C15
VIN
VIN
(a)
U1
U1
C10
C10
R8
R8
C3
C3
C4
C4
D2
D2
C8
C8
C9
C9
R7
R7
D4
D4
GND
GND
L2
L2
R4
R4
VOUT2
VOUT2
Z
L
V
R3
R3
OUT
22
input pins. Shortening the traces of the SW and BOOST
nodes reduces the parasitic trace inductance at these
nodes. This not only reduces EMI but also decreases
switching voltage spikes at these nodes.
Figures 16(a) and 16(b) shows how various external
components are placed around the SC2440. The
frequency-setting resistor is placed next to the ROSC pin
on the backside. The resistor is grounded to the ground
plane, which is then tied to anodes of the freewheeling
diodes with vias. These precautions reduce switching
noise pickup at the ROSC pin.
To ensure proper adhesion to the ground plane, avoid
using vias directly under the device. In figure 15 two
12mil vias are placed at the edge of the underside pad.
(b)
R9
R9
GND
GND
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