UG-883
ADP1974-EVALZ User Guide
Rev. 0 | Page 4 of 12
EVALUATION BOARD SETUP PROCEDURES
The
ADP1974-EVALZ
has many features that are customizable
via the resistors and capacitors on the evaluation board. Other
features are observable by adjusting the voltages applied to several
of the pins. Most features can be initially observed without making
any physical changes to the board, with the exception of R
S
. If
no R
S
is added, CL must be shorted to GND for most tests. If
testing the current-limit functionality, R
S
must be mounted to
the evaluation board. The steps in the following sections describe
how to use the
ADP1974-EVALZ
evaluation board.
QUICK START STEPS
To begin using the evaluation board, connect the external
equipment as described in the following sections.
GNDx Test Loop
The GND1 and GND2 test loops are the power ground
connection for the device via the GND pin and the external
bypass capacitors. Connect the ground connections from the
external equipment to this bus.
VIN Test Loop
Connect an external power supply from to VIN to GND1 or
GND2. The VIN test loop connects the positive input supply
voltage to the VIN pin. Connect the power supply to this bus
and keep the wires as short as possible to minimize the EMI
transmission.
EN Test Bus
The EN test bus is used to enable/disable the
ADP1974
via
the EN pin. Use one of the following methods to control the
ADP1974
. Do not leave the EN pin floating.
•
Use a jumper to connect the top two pins of the EN test
bus. This jumper connects EN to VIN and enables the
ADP1974
(see Figure 2).
PLACE
JUMPER
HERE
13517-
002
Figure 2. Enabled Jumper Position
•
Use a jumper to connect the bottom two pins of the EN test
bus. This jumper connects EN to GND and disables the
ADP1974
(see Figure 3).
PLACE
JUMPER
HERE
13517-
003
Figure 3. Disabled Jumper Position
•
Alternatively, connect a voltage between 0 V and 60 V to
the center pin of the EN test bus for independent control of
the EN pin voltage (see Figure 4). The
ADP1974
is enabled
when V
EN
≥ 1.25 V (typical).
CONNECT
EXTERNAL
SIGNAL
HERE
13517-
004
Figure 4. EN Pin Direct Connection
VREG Test Point
Connect a multimeter from VREG to GNDx. When V
EN
≥
1.25 V (typical), VREG rises to 5 V (typical).
MODE Test Bus
The MODE test bus is used to set the
ADP1974
in buck or
boost mode. Do not leave the MODE pin floating.
The state of the MODE pin can only be changed when the
ADP1974
is disabled via the EN pin or disabled due to a fault
condition.
•
Use a jumper to connect the top two pins of the MODE
bus. This jumper connects MODE to VREG and places
the
ADP1974
in buck/charge mode (see Figure 5).
PLACE
JUMPER
HERE
13517-
005
Figure 5. Enabled Jumper Position
•
Use a jumper to connect the bottom two pins of the MODE
test bus. This jumper connects MODE to GND and places
the
ADP1974
in boost/recycle mode (see Figure 6).
PLACE
JUMPER
HERE
13517-
006
Figure 6. Disabled Jumper Position
•
Alternatively, connect a voltage between 0 V and 5.5 V
to the center pin of the MODE test bus for independent
control of the MODE pin voltage (see Figure 7). The
MODE pin is logic high when V
MODE
≥ 1.20 V (typical).
CONNECT
EXTERNAL
SIGNAL
HERE
13517-
007
Figure 7. MODE Pin Direct Connection
