Datasheet

PGND/EP
Connect to AGND
5
FB
6
SS/TRK
3
EN
1
VIN
2
SYNC
4
AGND
7
VOUT
V
IN
C
IN
22 PF
Enable
R
FBT
See Table
C
SS
0.47 PF
R
FBB
See Table
Co
220 PF
LMZ23603
VOUT SS/TRK
SYNC
FB
VIN
EN
PGND
V
OUT
@ 3A
5V 5.62k 1.07k 9...36V
V
OUT
R
FBT
R
FBB
V
IN
Range
3.3V 3.32k 1.07k 7...36V
2.5V 2.26k 1.07k 6...36V
1.8V 1.87k 1.50k 6...36V
1.5V 1.00k 1.13k 6...36V
1.2V 1.07k 2.05k 6...36V
0.8V 0 8.06K 6...36V
AGND
6V 15.4k 2.37k 10...36V
1.0V 1.62k 6.49k 6...36V
LMZ23603
www.ti.com SNVS711I –MARCH 2011–REVISED OCTOBER 2013
Simplified Application Schematic
Connection Diagram
Figure 5. Top View - 7-Lead PFM
PIN DESCRIPTIONS
Pin Name Description
1 VIN Supply input — Nominal operating range is 6V to 36V . A small amount of internal capacitance is contained within the
package assembly. Additional external input capacitance is required between this pin and exposed pad (PGND).
2 SYNC Sync Input — Apply a CMOS logic level square wave whose frequency is between 650 kHz and 950 kHz to synchronize
the PWM operating frequency to an external frequency source. When not using synchronization connect to ground. The
module free running PWM frequency is 812 kHz (Typ).
3 EN Enable — Input to the precision enable comparator. Rising threshold is 1.279V typical. Once the module is enabled, a
21 uA source current is internally activated to facilitate programmable hysteresis.
4 AGND Analog Ground — Reference point for all stated voltages. Must be externally connected to EP/PGND.
5 FB Feedback — Internally connected to the regulation, over-voltage, and short-circuit comparators. The regulation
reference point is 0.796V at this input pin. Connect the feedback resistor divider between the output and AGND to set
the output voltage.
6 SS/TRK Soft-Start/Track — To extend the 1.6 mSec internal soft-start connect an external soft start capacitor. For tracking
connect to an external resistive divider connected to a higher priority supply rail. See Design Steps for the LMZ23603
Application section.
7 VOUT Output Voltage — Output from the internal inductor. Connect the output capacitor between this pin and exposed pad.
EP/PG EP/PG Exposed Pad / Power Ground Electrical path for the power circuits within the module. — NOT Internally connected to
ND ND AGND / pin 4. Used to dissipate heat from the package during operation. Must be electrically connected to pin 4
external to the package.
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