EN2340QI Datasheet, PDF (15/23 Pages) Enpirion, Inc. – 204A Voltage Mode Synchronous Buck PWM

the load. In this case, up to 1000µF of bulk
capacitance may be used at the load as long as the
minimum ESR between the device output and the
bulk capacitance is maintained. Table 4 shows the
recommended compensation components for
applications that require bulk capacitance at the
load.
PVIN (V)
4.5 to 14
≥10
<10
VOUT (V)
≥2.5
0.6 to 1.5
1.5 to 2.5
0.6 to 1.5
1.5 to 2.5
Min. ESR
4mΩ
9mΩ
7mΩ
12mΩ
9mΩ
Com pensation
COUT = 2x47µF/1206
Bulk Cap ≤ 1000µF
CA = 100pF
RA = 250kΩ
RCA = 5kΩ
Table 4: Minimum ESR for Bulk Capacitance at Load
Output ripple voltage is determined by the
aggregate output capacitor impedance. Capacitor
impedance, denoted as Z, is comprised of
capacitive reactance, effective series resistance,
ESR, and effective series inductance, ESL
reactance.
Placing output capacitors in parallel reduces the
impedance and will hence result in lower ripple
voltage.
1 ₌ 1 ₊ 1 _{+ ... +} 1
Z_Total Z₁ Z ₂
Z_n
Recommended Output Capacitors
De s cr iption
47µF, 6.3V, X5R,
20%, 1206
M FG
Murata
P/N
GRM31CR6 0J4 76 ME19 L
47µF, 10V, X5R,
20%, 1206
Taiyo
Yuden
LMK316BJ476ML- T
22µF, 10V, X5R,
20%, 0805
Panasonic ECJ-2FB1A226M
22µF, 10V, X5R,
20%, 0805
Taiyo
Yuden
LMK212BJ226MG- T
Table 5: Recommended Output Capacitors
EN2340QI
06878
October 9, 2013
www.altera.com/enpirion, Page 15
Rev E