lm21215a-1 National Semiconductor Corporation, lm21215a-1 Datasheet - Page 2

• Manufacturer Part Number: lm21215a-1
• Description: 15a High Efficiency Synchronous Buck Regulator With Frequency Synchronization
• Manufacturer: National Semiconductor Corporation

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LM21215AMHX-1
LM21215AMHE-1
Connection Diagram
Ordering Information
Pin Descriptions
LM21215AMH-1
Order Number
8,9,10
11-16
5,6,7
Pins
EP
17
18
19
20
1
2
3
4
Package Type
eTSSOP-20
eTSSOP-20
eTSSOP-20
Exposed Pad
PGOOD
SS/TRK
COMP
PGND
AGND
Name
SYNC
AVIN
PVIN
SW
EN
FB
Description
Frequency Synchronization input pin. Applying a clock signal to this pin will force
the device to switch at the clock frequency. If left unconnected, the frequency will
default to 500 kHz.
Soft-start control pin. An internal 2 µA current source charges an external capacitor
connected between this pin and AGND to set the output voltage ramp rate during
startup. This pin can also be used to configure the tracking feature.
Active high enable input for the device. If not used, the EN pin can be left open,
which will go high due to an internal current source.
Analog input voltage supply that generates the internal bias. It is recommended to
connect PVIN to AVIN through a low pass RC filter to minimize the influence of
input rail ripple and noise on the analog control circuitry.
Input voltage to the power switches inside the device. These pins should be
connected together at the device. A low ESR input capacitance should be located
as close as possible to these pins.
Power ground pins for the internal power switches.
Switch node pins. These pins should be tied together locally and connected to the
filter inductor.
Open-drain power good indicator.
Compensation pin is connected to the output of the voltage loop error amplifier.
Feedback pin is connected to the inverting input of the voltage loop error amplifier.
Quiet analog ground for the internal reference and bias circuitry.
Exposed metal pad on the underside of the package with an electrical and thermal
connection to PGND. It is recommended to connect this pad to the PC board
ground plane in order to improve thermal dissipation.
NSC Package Drawing
eTSSOP-20 Package
MYB20A
MYB20A
MYB20A
Top View
2
Package Marking
LM21215AMH-1
LM21215AMH-1
LM21215AMH-1
30152102
2500 Units Per Reel
250 Units Per Reel
73 Units per Rail
Supplied As