UCC3830- Datasheet, PDF (8/10 Pages) Texas Instruments – 5-Bit Microprocessor Power Supply Controller

UCC3830-4/-5/-6
APPLICATION INFORMATION (cont.)
Choosing the Input Capacitor
The input capacitors are chosen primarily based on their
switching frequency RMS current handling capability and
their voltage rating. The input capacitors must handle
virtually all of the RMS current at the switching fre-
quency, even if the circuit does not have an input induc-
tor. The switching current in the input capacitors
appears as shown in Figure 5.
The amount of RMS current in an Aluminum Electrolytic
capacitor has a strong impact on the reliability and life-
time of the capacitor. Other factors which affect the life
of an input capacitor are internal heat rise, external air-
flow, the amount of time that the circuit operates at maxi-
mum current and the operating voltage. The curves in
Figure 6 show the RMS current handled by the total input
capacitance in typical VRM circuits delivering 1.8V to
2.8V and powered from 5V.
Related Publications
U-156 and U-157 are Unitrode Application Notes describ-
ing the operation of the UC3886 and the UC3886/
UC3910 together in a Pentium® Pro application.
Typical Application
The UCC3830-x is ideal for converting the 5.0V system
bus into the required Pentium® Pro bus voltage. The
3.3V system bus can also be converted using the
UCC3830-x when the Pentium® Pro requires lower bus
voltages.
REFERENCE
DESIGNATOR
U1
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
C18
C19
C20
C21
C22
CR1
L1
Table I. Parts list.
DESCRIPTION
Unitrode UCC3830DWP-5 DAC/PWM
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sprague/Vishay 595D475X0016A2B, 4.7µF 16V Tantalum
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sanyo 6MV1500GX, 1500µF, 6.3V, Aluminum Electrolytic
Sprague 593D107X9010D2, 100µF, 6.3V Tantalum
0.10µF Ceramic
0.01µF Ceramic
0.01µF Ceramic
0.01µF Ceramic
1000pF Ceramic
0.10µF Ceramic
33pF NPO Ceramic
1500pF Ceramic
82pF NPO Ceramic
0.10µF Ceramic
0.10µF Ceramic
International Rectifier 32CTQ030 30V, 30A Schottky Diode
Micrometals T50-52B, 10 Turns #16AWG, 4.5µH
8
PACKAGE
SOIC-20 Wide
10x20mm Radial Can
10x20mm Radial Can
10x20mm Radial Can
10x20mm Radial Can
SPRAGUE Size A
10x20mm Radial Can
10x20mm Radial Can
10x20mm Radial Can
10x20mm Radial Can
10x20mm Radial Can
EIA Size D SMD
1206 SMD
0603 SMD
0603 SMD
0603 SMD
0603 SMD
1206 SMD
0603 SMD
0603 SMD
0603 SMD
1206 SMD
1206 SMD
TO-220AB
Toroid