TS30111 Datasheet, PDF (12/21 Pages) List of Unclassifed Manufacturers – High Efficiency 700mA Current-Mode Synchronous Buck DC/DC Converter, 1MHz

Typical Application Schematic
VCC
CBYPASS
10uF 35V
C BYPASS2
0.1uF
(optional)
VCC
EN
EN
BST
VSW
CBST
22nF
LOUT
3.3uH
DCATCH
(optional)
COUT1
22uF 10V
RTOP
FB
17.8K
VOUT
RBOT
10K
RPUP
10K
(optional)
PG
V_OUT
2.5V
PG
Figure 20: TS30111 Application Schematic
A minimal schematic suitable for most applications is shown on page 1. Figure 22 includes optional components that may be
considered to address specific issues as listed in the External Component Selection section.
PCB Layout
For proper operation and minimum EMI, care must be taken
during PCB layout. An improper layout can lead to issues
such as poor stability and regulation, noise sensitivity and
increased EMI radiation. (figure 23) The main guidelines are
the following:
The inductor must be placed close to the VSW pins and
connected directly to C_OUT in order to minimize the area
between the VSW pin, the inductor, the C_OUT capacitor and the
PGND pins. The trace area and length of the switching nodes
VSW and BST should be minimized.
• provide low inductive and resistive paths for loops with
high di/dt,
• provide low capacitive paths with respect to all the other
nodes for traces with high di/dt,
• sensitive nodes not assigned to power transmission
should be referenced to the analog signal ground (GND)
and be always separated from the power ground (PGND).
The negative ends of C_BYPASS, C_OUT and the Schottky diode D_CATCH
(optional) should be placed close to each other and connected
using a wide trace. Vias must be used to connect the PGND
node to the ground plane. The PGND node must be placed as
close as possible to the TS30111 PGND pins to avoid additional
voltage drop in traces.
The bypass capacitor C_BYPASS (optionally paralleled to a 0.1µF
capacitor) must be placed close to the VCC pins of TS30111.
For the adjustable output voltage version of the TS30111,
feedback resistors R_BOT and R_TOP are required for Vout settings
greater than 0.8V and should be placed close to the TS30111
in order to keep the traces of the sensitive node FB as short
as possible and away from switching signals. R_BOT should be
connected to the analog ground pin (GND) directly and should
never be connected to the ground plane. The analog ground
trace (GND) should be connected in only one point to the
power ground (PGND). A good connection point is under the
TS30111 package to the exposed thermal pad and vias which
are connected to PGND. R_TOP will be connected to the V_OUT
node using a trace that ends close to the actual load.
For fixed output voltage versions of the TS30111, R_BOT and R_TOP
are not required and the FB pin should be connected directly
to the V_OUT.
TS30111
Final Datasheet
June 2, 2015
Rev 1.0
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