This user's guide describes the characteristics, operation, and use of the TPS212xEVM (EVM). This
document contains the EVM schematics, board layout, bill of materials (BOM), and necessary instructions
on how to properly operate the EVM.
The TPS212x EVM is an evaluation module for TI's TPS212x family of two-input, one-output power
multiplexers. This device automatically detects, selects, and seamlessly transitions between two power
supplies, each operating from 2.7 V to 22 V. The TPS2121 device, the VSON hot-rod package, can deliver
up to 4 A while the TPS2120, WCSP package, can handle up to 3 A. This user's guide contains the EVM
schematics, board layout, list of materials, and necessary instructions on how to properly operate the
EVM.
The EVM has test points for convenient access to all critical voltages and pins, and jumpers to configure
the different modes of operation. There are also jumpers to configure input and output capacitance, output
load resistance, current limit, and the adjustable soft-start time.
1.1Features
The TPS212x EVM offers many features including:
•Uninterrupted system power with seamless switchover
•Overvoltage protection
•Low RONresistance at both inputs: 50 mΩ typical
•Multiple configurations for different modes of operation
1.2Applications
The TPS212x power multiplexer can be used in many applications, including:
•Add-on cards (PCIE, RAID, Network)
•ePos
•Video surveillance
•ORing controllers
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1.3Description
The TPS212x EVM power MUX evaluation board enables evaluation of the TPS212x family of Power
MUX devices. Although both variants (TPS2121EVM-042 or TPS2120EVM-023) contain different jumpers
and connectors, they will function almost identically. Both EVMs allow operation at different input voltages,
although the resistors and jumpers are configured for operation at 3.3 V, 5 V, and 12 V. See the TPS212x
data sheet for more information regarding these settings.
The TPS212x EVMs also allow multiple modes of operation. By configuring the jumpers, the EVMs
automatically detect, select, and seamlessly transition between available inputs. The different modes of
operation are explained in Table 1.
This section provides an overview of the TPS212x evaluation board input and output jumpers. Table 2
describes the input and output connectors on the EVM. Table 3 describes the different test points and
functionality, while Table 4 describes the jumper functionality and configurations.
Table 2. TPS2121 Input and Output Connector Functionality
InputConnectorLabelDescription
J21VIN1 + , GND -Input block header for VIN1
VIN1
VIN2
VOUT
GND
TP12, TP13, TP14, TP15,
TP16, TP17, TP18, TP19
TP8VIN1Input test point for VIN1
TP6VIN1_SNSInput sense connector for VIN1
J14VIN2 + , GND -Input block header for VIN2
TP11VIN2Input test point for VIN2
TP6VIN2_SNSInput sense connector for VIN2
J15VOUT +, GND -Output block header for VOUT
TP9VOUTOutput test point for VOUT
TP7VOUT_SNSOutput sense connector for VOUT
General Configurations
GNDTest point for GND
Table 3. TPS2121 Test Points Description
InputConnectorLabelDescription
VIN1
VIN2
VOUTTP5STStatus test point
TP1OV1Overvoltage test point for VIN1
TP4PR1Priority test point for VIN1
TP2OV2Overvoltage test point for VIN2
TP3CP2Comparator test point for VIN2
This section provides an overview of the TPS212x evaluation board input and output jumpers. Table 2
describes the input and output connectors on the EVM. Table 3 describes the different test points and
functionality, while Table 4 describes the jumper functionality and configurations.
Table 5. TPS2120 Input and Output Connector Functionality
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Female header for custom output resistance,
capacitance
Sets adjustable hysteresis
Position 1-2 sets ST, 2-3 disables (GND)
Current limit control
Position 1-2 position sets 4.5 A maximum
Position 2-3 sets 2 A maximum
No jumper sets 1.5 A maximum
InputConnectorLabelDescription
J10VIN1 + , GND -Input block header for VIN1
VIN1
VIN2
VOUT
GND
TP12, TP13, TP14, TP15,
TP16, TP17, TP18, TP19
TP7VIN1Input test point for VIN1
TP5VIN1_SNSInput sense connector for VIN1
J17VIN2 + , GND -Input block header for VIN2
TP11VIN2Input test point for VIN2
TP10VIN2_SNSInput sense connector for VIN2
J11VOUT +, GND -Output block header for VOUT
TP8VOUTOutput test point for VOUT
TP6VOUT_SNSOutput sense connector for VOUT
GNDTest point for GND
Table 6. TPS2120 Test Points Description
InputConnectorLabelDescription
VIN1
VIN2
VOUTTP4STStatus test point
TP1OV1Overvoltage test point for VIN1
TP3PR1Priority test point for VIN1
TP2OV2Overvoltage test point for VIN2
TP9SELSelect test point
This chapter describes the proper setup for the TPS212x power MUX EVM. This section explains the
different configuration modes present on each EVM, and the required jumper positions to enable each
configuration.
3.1TPS212x EVM Test Equipment
Read the TPS212x data sheet before using the EVM.
The following test equipment is recommended:
•Storage oscilloscope
•Current problem
•Two adjustable power supples, 0 V–22 V at 4 A maximum
•A passive or active load
3.2Setting up the TPS2121 EVM
Make sure the TPS2121 evaluation board has the default jumper settings as Table 8 shows.
Table 8. Default Jumper Settings for TPS2121 Evaluation Board
J2010 ΩInstall
J22SS (10 nF)Install
JP1PR1Jump pins 2 and 3
JP2STJump pins 2 and 3
JP3ILIM (4.5 A maximum)Jump pins 1 and 2
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The default jumper configuration sets the Internal Voltage Reference (VREF) configuration. Since the
voltage on the priority pin is set for 3.3-V operation and CP2 is grounded, priority will be given to VIN1.
Therefore, VIN1 can be set to 3.3 V, and the device will prioritize VIN1 even if VIN2 is at a higher voltage.
See the data sheet for more information regarding the configuration settings.
3.3Setting up the TPS2120 EVM
Make sure the TPS2120 evaluation board has default jumper settings as Table 9 shows.
Table 9. Default Jumper Settings for TPS2120 Evaluation Board
The default jumper configuration sets the Internal Voltage Reference (VREF) configuration. Since the
voltage on the priority pin is set for 3.3-V operation and SEL is grounded, the priority is given to VIN1.
Therefore, VIN1 can be set to 3.3 V, and the device will prioritize VIN1 even if VIN2 is at a higher voltage.
See the data sheet for more information regarding the configuration settings.
4Board Layout
Figure 1 and Figure 2 show the test equipment setup for the TPS2121 and TPS2120, respectively.