Datasheet

ADP2119/ADP2120 Data Sheet
Rev. A | Page 6 of 24
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
10
EN
ADP2119/ADP2120
EXPOSED
PAD
1
VIN
9
SYNC/MODE
2
PVIN
8
PGOOD
3
SW
7
TRK
4
PGND
6
FB
5
GND
NOTES
1. THE EXPOSED PAD SHOULD BE SOLDERED TO
AN EXTERNAL GROUND PLANE UNDERNEATH
THE IC FOR THERMAL DISSIPATION.
08716-003
Figure 3. Pin Configuration (Top View)
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 VIN Bias Voltage Input Pin. Connect a bypass capacitor (0.1 µF minimum) between this pin and GND and a
small (10 Ω) resistor between this pin and PVIN.
2 PVIN Power Input Pin. Connect this pin to the input power source. Connect a bypass capacitor between this pin and PGND.
3 SW Switch Node Output. Connect this pin to the output inductor.
4 PGND Power Ground. Connect this pin to the power ground plane and to the high current return for the power MOSFET.
5 GND Analog Ground. Connect this pin to the ground plane.
6 FB Feedback Voltage Sense Input. Connect this pin to a resistor divider from V
OUT
. For the fixed output version,
connect to V
OUT
directly.
7 TRK Tracking Input. To track a master voltage, drive TRK from a resistor divider from the master voltage. If the
tracking function is not used, connect TRK to VIN.
8 PGOOD Power-Good Output (Open Drain). Connect this pin to a resistor to any pull-up voltage < 5.5 V.
9 SYNC/MODE Synchronization Input (SYNC). Connect this pin to an external clock between 1 MHz and 2 MHz to synchronize
the switching frequency to the external clock (see the Oscillator and Synchronization section for details).
FPWM/PFM Selection (MODE). When this pin is connected to VIN, the PFM mode is disabled and the part works
in continuous conduction mode (CCM) only. When this pin is connected to ground, the PFM mode is enabled
and becomes active at light loads.
10 EN Precision Threshold Enable Input Pin. An external resistor divider can be used to set the turn-on threshold. To
enable the part automatically, connect the EN pin to VIN. This pin has a 1 MΩ pull-down resistor to GND.
EPAD
Exposed Pad
The exposed pad should be soldered to an external ground plane underneath the IC for thermal dissipation.