SC251EVB SEMTECH [Semtech Corporation], SC251EVB Datasheet - Page 7

• Manufacturer Part Number: SC251EVB
• Description: Step-down DC-DC Converter with Bias LDO for WCDMA Amplifi ers
• Manufacturer: SEMTECH [Semtech Corporation]

Pin Description
POWER MANAGEMENT
© 2006 Semtech Corp.
Pin#
10
T
1
2
3
4
5
6
7
8
9
Thermal Pad
Pin Name
VMODE
PGND
VDAC
VOUT
VREF
GND
VIN
GD
EN
LX
Pin Function
Input supply pin.
A 2.85V LDO reference voltage supply - 10mA max load that can be used as a supply
for power amplifi er bias inputs.
A push pull external PFET Gate drive control output - connect to the gate of an external
MOSFET to control a low resistance path between V
drop is needed (optional - if not used leave fl oating). A low state turns on the MOSFET.
Enable pin - controls both the switching converter and the VREF output. Active high.
Input control to select the V
Analog control voltage input - ranges between 0.3 and 1.2V for exponential control of
V
optional low R
System and logic ground.
Output voltage pin.
Ground reference for internal N-channel MOSFET.
Switch node connection to inductor. This pin connects to the drains of the internal
main and synchronous power MOSFET switches.
Pad for heatsinking purposes. Connect to ground plane using multiple vias.
Not connected internally.
OUT
, V
DAC
> 1.28 enables pass-through mode (using internal pass MOSFET or
DSON
MOSFET controlled by GD).
7
DAC
to V
OUT
profi le (high = low power, low = high power).
IN
and V
OUT
when low voltage
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