Epson Power Supply IC S1F70000 Technical Manual page 161

S1F76300 Series
Notes
100 H L 1mH, C
S1F76310M1A0
• Peff = 70% when L = 220 H (leadless inductor),
f
V = 1.5V, = 32kHz, I
I1 CLK
• Peff = 75% when L = 220 H (drum coil),
f
V = 1.5V, = 32kHz, I
I1 CLK
• Peff = 80% when L = 300 H (toroidal coil),
f
V = 1.5V, = 32kHz, I
I1 CLK
S1F76310M1B0
• Peff = 70% when L = 220 H (leadless inductor),
f
V = 1.5V, = 32kHz, I
I1 CLK
• Peff = 75% when L = 220 H (drum coil),
f
V =1.5V, = 32kHz, I
I1 CLK
• Peff = 80% when L = 300 H (toroidal coil),
f
V = 1.5V, = 32kHz, I
I1 CLK
External components
The performance characteristics of switching regulators
depend greatly on the choice of external components.
Observing the following guidelines will ensure high
performance and maximum efficiency.
4–16
10 F, D = Schottky diode
= 4mA
O
= 6mA
O
= 7mA
O
= 8mA
O
= 9mA
O
= 10mA
O
Inductor
Use an inductor with low direct-current resistance and
low losses.
Leadless
Pre-wound, leadless inductors using surface-mount
technology are the most suitable for portable equipment
and other space-critical applications.
Drum coil
Avoid using drum coils because their magnetic field
can induce noise.
Toroidal coil
Use a toroidal coil to virtually eliminate magnetic field
leakage, reduce losses and improve performance.
Diode
Use a Schottky barrier diode with a high switching
speed and low forward voltage drop, V
Capacitor
To minimize ripple voltages, use a capacitor with a
small equivalent direct-current resistance for smooth-
ing.
EPSON
.
F
S1F70000 Series
Technical Manual