EP5358XUI Datasheet, PDF (12/16 Pages) Altera Corporation – 600mA PowerSoC Synchronous Buck Regulator with Integrated Inductor

V_IN
4.7uF
PVIN
AVIN
VSENSE
VOUT
ENABLE
Ra
VFB
VSO
VS1
Rb
VS2 _{PGND AGND}
V_OUT
10µF
Figure 8: EP5358LUI using external divider
The output voltage is selected by the following
formula:
( ) V_OUT
= 0.6V
1+
Ra
Rb
R_a must be chosen as 237KΩ to maintain loop
gain. Then R_b is given as:
R ^{= 142.2x103 Ω}
b _{VOUT − 0.6}
V_OUT can be programmed over the range of
0.6V to (V_IN – 0.25V).
NOTE: Dynamic Voltage Scaling is not allowed
between internal preset voltages and external
divider.
EP5358HUI High VID Range Programming
The EP5358HUI V_OUT settings are optimized
for higher nominal voltages such as those
required to power IO, RF, or IC memory. The
preset voltages range from 1.8V to 3.3V.
There are eight (8) preset output voltage
settings. The EP5358HUI does not have an
external divider option. As with the
EP5358LUI, the VID pin settings can be
changed while the device is enabled.
Table 2 shows the VS0-VS2 pin logic states for
the EP5358HUI and the associated output
voltage levels. A logic “1” indicates a
connection to AVIN or to a “high” logic voltage
level. A logic “0” indicates a connection to
AGND or to a “low” logic voltage level. These
pins can be either hardwired to AVIN or AGND
or alternatively can be driven by standard logic
EP5358LUI/EP5358HUI
levels. Logic levels are defined in the electrical
characteristics table. Any level between the
logic high and logic low is indeterminate.
These pins must not be left floating.
Table 2: EP5358HUI VID Voltage Select Settings
VS2
VS1
VS0
VOUT
0
0
0
3.3
0
0
1
3.0
0
1
0
2.9
0
1
1
2.6
1
0
0
2.5
1
0
1
2.2
1
1
0
2.1
1
1
1
1.8
Custom VID Setting Adjustment
4.7uF
AVIN
PVIN
VOUT
EP5358xUI
VSO
VS1
VS2
ENABLE
PGND
VSENSE
AGND
Rs
5.0pF
10uF
Figure 9: EP5358xUI with RC inserted in VSENSE
path to modify VID output voltages.
It is possible to adjust VOUT for a given VID
setting by inserting a parallel RC combination
in the VSENSE path as shown in figure 9. The
capacitor value is 5.0pF to ensure stability.
Note that the value of VOUT can only be
increased from its nominal setting
(VOUT_NEW>VOUT_OLD):
For EP5358LUI:
Rs_L
= 711* _{}^{VVOOUUTTNOELWD}

−1_kOhms

For EP5358HUI:
Rs_H
= 356 * _{}^{VVOOUUTTNOELWD}

−1_kOhms

VOUT_NEW is the desired “new” VOUT.
www.altera.com/enpirion Page 12
03541
October 11, 2013
Rev F