Texas Instruments LM21212-1EVM Evaluation Board LM21212-1EVM/NOPB LM21212-1EVM/NOPB Datenbogen
Produktcode
LM21212-1EVM/NOPB
Powering and Loading Considerations
Table 1. Connection Descriptions
Terminal Silkscreen
Description
VIN
This terminal is the input voltage to the device. The evaluation board will operate over the input voltage
range of 2.95V to 5.5V.
range of 2.95V to 5.5V.
GND
These terminals are the ground connections to the device. The input power ground should be connected
next to the input V
next to the input V
IN
connection, and the output power ground next to the V
OUT
connection.
VOUT
This terminal connects to the output voltage of the power supply and should be connected to the load.
ENABLE
This terminal connects to the enable pin of the device. This terminal can be left floating or driven
externally. If left floating, a 2µA current source will pull the pin high, thereby enabling the device. If driven
externally, a voltage typically less than 1.2V will disable the device.
externally. If left floating, a 2µA current source will pull the pin high, thereby enabling the device. If driven
externally, a voltage typically less than 1.2V will disable the device.
SS/TRK
This terminal provides access to the SS/TRK pin of the device. Connections to this terminal are not
needed for most applications. The feedback pin of the device will track the voltage on the SS/TRK pin if
it is driven with an external voltage source that is below the 0.6V reference.
needed for most applications. The feedback pin of the device will track the voltage on the SS/TRK pin if
it is driven with an external voltage source that is below the 0.6V reference.
PGOOD
This terminal connects to the power good output of the device. This pin is pulled up through a 10 k
Ω
pull-up resistor to V
IN
.
AC INJ
This terminal block allows the user to insert an AC injection signal across a 49.9
Ω
resistor for open-loop
gain bode measurements. A jumper shorts out this resistor when it is not needed.
SWITCH
This terminal allows easy probing of the switch node. Do not apply any external voltage source to this
pin.
pin.
SYNC
This terminal connects to the SYNC pin of the device. The LM21212-1 can synchronize the SWITCH pin
to a SYNC signal with a frequency between 300kHz and 1.5MHz. If this pin is left open, the switching
frequency will default to 1MHz.
to a SYNC signal with a frequency between 300kHz and 1.5MHz. If this pin is left open, the switching
frequency will default to 1MHz.
VIN_SENSE+,
These terminals allow a sense connection on the board for accurate V
IN
and V
OUT
measurements,
VIN_SENSE-
respectively.
VOUT_SENSE+,
VOUT_SENSE-
3
SNVA467B – February 2011 – Revised May 2013
AN-2107 LM21212-1 Evaluation Board
Copyright © 2011–2013, Texas Instruments Incorporated