EP5358XUI Datasheet, PDF (13/16 Pages) Altera Corporation – 600mA PowerSoC Synchronous Buck Regulator with Integrated Inductor

VOUT_OLD is the VID table output voltage.
For a given Rs Value, the VOUT_NEW for VID
settings is determined by the following
equations:
EP5358LUI:
VOUT_NEW
= VOUT_{OLD }
Rs_L
711


+
1_{}Volts
EP5358HUI:
VOUT_NEW
= VOUT_{OLD }
Rs_H
356


+ 1_Volts

NOTE: The amount of adjustment is limited to
approximately 15% of the nominal VID setting.
NOTE: Adjusting VOUT using this method will
increase the tolerance of the output voltage.
The larger the adjustment, the greater the
increase in tolerance.
Power-Up/Down Sequencing
During power-up, ENABLE should not be
asserted before PVIN, and PVIN should not be
asserted before AVIN. The PVIN should never
be powered when AVIN is off. During power
down, the AVIN should not be powered down
before the PVIN. Tying PVIN and AVIN or all
three pins (AVIN, PVIN, ENABLE) together
during power up or power down meets these
requirements.
Pre-Bias Start-up
The EP5358xUI does not support startup into a
pre-biased condition. Be sure the output
capacitors are not charged or the output of the
EP5358xUI is not pre-biased when the
EP5358xUI is first enabled.
EP5358LUI/EP5358HUI
Input Filter Capacitor
For I_LOAD ≤ 500mA, C_IN = 2.2uF
For I_LOAD > 500mA C_IN = 4.7uF.
0402 capacitor case size is acceptable.
The input capacitor must use a X5R or X7R or
equivalent dielectric formulation. Y5V or
equivalent dielectric formulations lose
capacitance with frequency, bias, and with
temperature, and are not suitable for switch-
mode DC-DC converter input filter applications.
Output Filter Capacitor
For VIN ≤ 4.3V, C_{OUT_MIN} = 10uF 0603 MLCC.
For VIN > 4.3V, C_{OUT_MIN} = 10uF 0805 MLCC.
Ripple performance can be improved by using
2x10µF 0603 MLCC capacitors (for any
allowed VIN).
The maximum output filter capacitance next to
the output pins of the device is 60µF low ESR
MLCC capacitance. V_OUT has to be sensed at
the last output filter capacitor next to the
EP5358xUI.
Additional bulk capacitance for decoupling and
bypass can be placed at the load as long as
there is sufficient separation between the V_OUT
Sense point and the bulk capacitance.
Excess total capacitance on the output (Output
Filter + Bulk) can cause an over-current
condition at startup. Refer to the section on
Soft-Start for the maximum total capacitance
on the output.
The output capacitor must use a X5R or X7R
or equivalent dielectric formulation. Y5V or
equivalent dielectric formulations lose
capacitance with frequency, bias, and
temperature and are not suitable for switch-
mode DC-DC converter output filter
applications.
03541
October 11, 2013
www.altera.com/enpirion Page 13
Rev F