Enpirion
®
Power Evaluation Board User Guide
EN2340QI
PowerSoC
Alternatively, you can control the ENA jumper with an external source. For dual supply
mode, you can also tie Enable to AVIN by removing NR1 from the back side, putting a
short across the FB1 footprint, and connecting the middle point of J3 to the left pin using
a shorting jumper. Please review the Power Up Sequence section in the datasheet
before experimenting with various turn on/off combinations.
CAUTION: Please refer to the datasheet for the maximum voltages on the 12V
(PVIN) and AVIN inputs, and maximum slew rates for the PVIN input.
STEP 6A: Power Up/Down Behavior
– Connect a pulse generator (output disabled)
signal to the clip-on test point below ENA and Ground. Set the pulse amplitude to swing
from 0 to 2.5 volts. Set the pulse period to 10msec. and duty cycle to 50%. Hook up
oscilloscope probes to ENA, SS, POK and VOUT with clean ground returns. Apply
power to evaluation board. Enable pulse generator output. Observe the SS capacitor
and VOUT voltage ramps as ENA goes high and again as ENA goes low. The device
when powered down ramps down the output voltage in a controlled manner before fully
shutting down. The output voltage level when POK is asserted /de-asserted as the
device is powered up / down may be observed as well as the clean output voltage ramp
and POK signals.
STEP 7: External Clock Synchronization / Spread Spectrum Modes
: In order to
activate this mode, it may be necessary to a solder a SMA connector at J4. Alternately
the input clock signal leads may be directly soldered to the through holes of J4 as
shown below.
Figure 3: SMA Connector for External Clock Input
GND
Ext. Clock
Page 4 of 10