Texas Instruments Evaluation Board for the LM21212-2 LM21212-2EVM/NOPB LM21212-2EVM/NOPB Scheda Tecnica
Codici prodotto
LM21212-2EVM/NOPB
FB
PGOOD
VIN
LM21212-2
VOUT
AGND
COMP
PVIN
FADJ
SW
EN
C6
L1
R
C1
C
C1
C
C2
C
C3
R
FB1
R
FB2
R
C2
PGND
AVIN
C1
1
11-16
3
4
17
19
18
20
8,9,10
5,6,7
R1
SS /
TRK
TRK
C
SS
2
eTSSOP-20
C7
C8
Vin
R
PG
C3
C4
C5
SS_TRK
R
AC
ENABLE
R
EN1
R
EN2
GND
GND
C9
PGOOD
SWITCH
AC INJ
VOUT
SENSE+
SENSE+
VOUT
SENSE-
SENSE-
VIN
SENSE-
VIN
SENSE+
V
IN
= 2.95V to 5.5V
V
OUT
= 1.2V, up to 12A
0.1
P
F
820 pF
165
:
10 k
:
49.9
:
10 k
:
11.0 k
:
1800 pF
56 pF
10 k
:
100
P
F
0.56
P
H
100
P
F
open
open
1
:
1
P
F
0.033
P
F
R
ADJ
95.3 k
:
User's Guide
SNVA480A – May 2011 – Revised May 2013
AN-2140 LM21212-2 Evaluation Board
1
Introduction
This evaluation board provides a solution to examine the high efficiency LM21212-2 buck switching
regulator. The LM21212-2 is capable of driving up to 12A of continuous load current with excellent output
voltage accuracy due to its ±1% internal reference. The LM21212-2 is capable of down converting from an
input voltage between 2.95V and 5.5V. Fault protection features include current limit, output power good,
and output over-voltage protection. The LM21212-2 has a programmable switching frequency can be set
between 300 kHz and 1.55 MHz with an external resistor. The dual function soft-start/tracking pin can be
used to control the startup response of the LM21212-2, and the precision enable pin can be used to easily
sequence the LM21212-2 in applications with sequencing requirements.
regulator. The LM21212-2 is capable of driving up to 12A of continuous load current with excellent output
voltage accuracy due to its ±1% internal reference. The LM21212-2 is capable of down converting from an
input voltage between 2.95V and 5.5V. Fault protection features include current limit, output power good,
and output over-voltage protection. The LM21212-2 has a programmable switching frequency can be set
between 300 kHz and 1.55 MHz with an external resistor. The dual function soft-start/tracking pin can be
used to control the startup response of the LM21212-2, and the precision enable pin can be used to easily
sequence the LM21212-2 in applications with sequencing requirements.
The LM21212-2 evaluation board has been optimized to work from 2.95V to 5.5V, achieving a balance
between overall solution size and regulator efficiency. The evaluation board measures just over 2” x 2” on
a four layer PCB, and exhibits a junction-to-ambient thermal impedance (
between overall solution size and regulator efficiency. The evaluation board measures just over 2” x 2” on
a four layer PCB, and exhibits a junction-to-ambient thermal impedance (
θ
JA
) of 24°C/W with no air flow.
The power stage and compensation components of the LM21212-2 evaluation board have been optimized
for an input voltage of 5V, but for testing purposes, the input can be varied across the entire operating
range. The output voltage of the evaluation board is nominally 1.2V, but this voltage can be easily
changed to any voltage between 0.6V and V
for an input voltage of 5V, but for testing purposes, the input can be varied across the entire operating
range. The output voltage of the evaluation board is nominally 1.2V, but this voltage can be easily
changed to any voltage between 0.6V and V
IN
by modifying the feedback resistor network.
2
Evaluation Board Schematic
Figure 1. Evaluation Board Schematic
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1
SNVA480A – May 2011 – Revised May 2013
AN-2140 LM21212-2 Evaluation Board
Copyright © 2011–2013, Texas Instruments Incorporated