LT1616ES6#TRM Linear Technology, LT1616ES6#TRM Datasheet - Page 12

• Manufacturer Part Number: LT1616ES6#TRM
• Description: IC SW REG STEP-DN 1.4MHZ SOT23-6
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LT1616ES6#TRM

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 5V
• Current - Output: 600mA
• Frequency - Switching: 1.4MHz
• Voltage - Input: 3.6 ~ 25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Other names: LT1616ES6#TRMTR

APPLICATIO S I FOR ATIO
LT1616
catch diode (D1) and the input capacitor (C1). The loop
formed by these components should be as small as
possible. Furthermore, the system ground should be tied
to the regulator ground in only one place; this prevents the
switched current from injecting noise into the system
ground. These components, along with the inductor and
output capacitor, should be placed on the same side of the
circuit board, and their connections should be made on
that layer. Place a local, unbroken ground plane below
these components, and tie this ground plane to system
ground at one location, ideally at the ground terminal of the
output capacitor C2. Additionally, the SW and BOOST
nodes should be kept as small as possible. Finally, keep
the FB node as small as possible so that the ground pin and
ground traces will shield it from the SW and BOOST nodes.
Figure 9 shows component placement with trace, ground
plane and via locations. Include two vias near the GND pin
of the LT1616 to help remove heat from the LT1616 to the
ground plane.
12
U
U
SHUTDOWN
Figure 9. A Good PCB Layout Ensures Proper, Low EMI Operation
V
IN
W
VIAS TO LOCAL GROUND PLANE
OUTLINE OF LOCAL GROUND PLANE
U
Outputs Greater than 6V
For outputs greater than 6V, connect a diode (such as a
1N4148) from the SW pin to V
from ringing above V
tion. The 12V output circuit below shows the location of
this diode. Also note that for outputs above 10V, the input
voltage range will be limited by the maximum rating of the
BOOST pin. The 12V circuit shows how to overcome this
limitation using an additional Zener diode.
Other Linear Technology Publications
Application notes AN19, AN35 and AN44 contain more
detailed descriptions and design information for Buck
regulators and other switching regulators. The LT1376
data sheet has a more extensive discussion of output
ripple, loop compensation and stability testing. Design
Note DN100 shows how to generate a bipolar output
supply using a Buck regulator.
1616 F09
IN
during discontinuous mode opera-
V
SYSTEM
GROUND
OUT
IN
to prevent the SW pin