EV1320QI Datasheet, PDF (14/20 Pages) Enpirion, Inc. – The EV1320QI is a DC to DC converter specifically designed for memory termination applications.

Application Information
VDDQ
22µF
OPTIONAL
3.3V
1Ω
10µF
EV1320QI
VREF
DIVIDER
VREF
VDDQ
VOUT
C1P
EV 1320QI
PGND
22µF +
1 x 10µF
ENABLE
C1N
PGND
AVIN
SS
15 nF
AGND
VTT
22µF
Figure 6. General Application Circuit for 2A Operation
General Application Circuit
Figure 6 shows a typical application circuit for the
EV1320QI. The resistor before the AVIN capacitor
is optional, but recommended if AVIN supply is
noisy.
NOTE: The output filter capacitor section assumes
that there is additional decoupling on the VTT
island(s) of approximately 100µF per amp of VTT
current. If this VTT decoupling is not present,
additional bulk capacitance will be required on the
EV1320QI output.
Soft-Start ramp rate is set by choice of the soft start
capacitor (C_SS) as described in the soft start
section.
Power Up Sequence
During power up, neither ENABLE nor VDDQ
should be asserted before AVIN. There are two
common acceptable turn-on/off sequences for the
device. ENABLE can be tied to AVIN and come up
with it, and VDDQ can be ramped up and down as
needed. In this case, the output will attempt to track
VDDQ. Alternatively, VDDQ can be brought high
after AVIN is asserted, and the device can be
turned on and off by toggling the ENABLE pin. In
this case, the output will ramp up as determined by
the soft-start capacitor, and it will turn off as
described in “Enable Operation” section.
Input Capacitors
A 22µF 4V X5R MLCC capacitor is required at the
VDDQ input for 2A applications. A 10µF may be
used for under 1A applications. The input capacitor
must be placed at the position closest to the VDDQ
pins of the EV1320QI. Either 0603 or 0805 case
size is acceptable. The capacitors should be
06831
October 11, 2013
www.altera.com/enpirion, Page 14
Rev B