FAN5092MTC Fairchild Semiconductor, FAN5092MTC Datasheet - Page 17

• Manufacturer Part Number: FAN5092MTC
• Description: IC CTRLR DC/DC SYNC BUCK 28TSSOP
• Manufacturer: Fairchild Semiconductor
• Type: Step-Down (Buck)r

Specifications of FAN5092MTC

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.1 ~ 5 V
• Frequency - Switching: 200kHz ~ 2MHz
• Voltage - Input: 12V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP
• Output Voltage: 17 V
• Mounting Style: SMD/SMT
• Operating Temperature Range: 0 C to + 70 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: FAN5092MTC_NL; FAN5092MTC_NL

PRODUCT SPECIFICATION
ESR. The only type of aluminum capacitor used should be
those that have an ESR rated at 100kHz. Consult Application
Bulletin AB-14 for detailed information on output capacitor
selection.
For higher frequency applications, particularly those running
the FAN5092 oscillator at >1MHz, Oscon or ceramic capaci-
tors may be considered. They have much smaller ESR than
comparable electrolytics, but also much smaller capacitance.
The output capacitance should also include a number of
small value ceramic capacitors placed as close as possible to
the processor; 0.1µF and 0.01µF are recommended values.
Input Filter
The DC-DC converter design may include an input inductor
between the system main supply and the converter input as
shown in Figure 4. This inductor serves to isolate the main
supply from the noise in the switching portion of the DC-DC
converter, and to limit the inrush current into the input capac-
itors during power up. A value of 1.3µH is recommended.
It is necessary to have some low ESR capacitors at the input
to the converter. These capacitors deliver current when the
high side MOSFET switches on. Because of the interleaving,
the number of such capacitors required is greatly reduced
from that required for a single-slice buck converter. Figure 5
shows 3 x 1000 F, but the exact number required will vary
with the output voltage and current, according to the formula
REV. 1.0.7 6/20/02
I
rms
=
I
-------- - 4DC 16DC
out
4
–
2
for the four slice FAN5092, where DC is the duty cycle,
DC = Vout / Vin. Capacitor ripple current rating is a function
of temperature, and so the manufacturer should be contacted
to find out the ripple current rating at the expected opera-
tional temperature. For details on the design of an input filter,
refer to Applications Bulletin AB-16.
Design Considerations and Component
Selection
Additional information on design and component selection
may be found in Fairchild’s Application Note 59.
+12V
Figure 4. Input Filter
1.3 H
1000 F, 16V
Electrolytic
Vin
FAN5092
17