FAN6520AMX Fairchild Semiconductor, FAN6520AMX Datasheet - Page 12

• Manufacturer Part Number: FAN6520AMX
• Description: IC CTRLR PWM SYNC BUCK SGL 8SOIC
• Manufacturer: Fairchild Semiconductor
• Type: Step-Down (Buck)r

Specifications of FAN6520AMX

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 5.5 V
• Frequency - Switching: 300kHz
• Voltage - Input: 4.5 ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Power - Output: 715mW
• Topology: Boost, Buck
• Output Voltage: 0.8 V to 5.5 V
• Switching Frequency: 340 KHz
• Duty Cycle (max): 100 %
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Synchronous Pin: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: FAN6520AMXTR; FAN6520AMX_NL; FAN6520AMX_NLTR; FAN6520AMX_NLTR

©2005 Fairchild Semiconductor Corporation
FAN6520A Rev. 1.0.5
Low-Side Losses
Q2, however, switches on or off with its parallel Shottky
diode conducting, therefore V
proportional to V
and Q2 can be selected based on R
Conduction losses for Q2 are given by:
P
where R
highest operating junction temperature and
Since D
duces a conservative result, simplifying the calculation.
The maximum power dissipation (P
of the maximum allowable die temperature of the low-
D
COND
=
V OUT
-----------------
V IN
= (1-D) × I
MIN
DS(ON)
< 20% for portable computers, (1-D) ≈ 1 pro-
is the minimum duty cycle for the converter.
is the R
DS
OUT
, Q2’s switching losses are negligible
2
× R
DS(ON)
DS(ON)
DS
of the MOSFET at the
Ý 0.5V. Since P
D(MAX
DS(ON)
) ) is a function
only.
SW
(29)
is
side MOSFET, the θ
ambient temperature rise:
depends primarily on the amount of PCB area that can
be devoted to heat sinking. Refer to Fairchild Application
Note AN-1029 Maximum Power Enhancement Tech-
niques for SO-8 Power MOSFETs at
semi.com/an/AN/AN-1029.pdf
P D MAX
12
(
)
=
T J MAX
--------------------------------------------------------- -
(
J-A
θ J A
) T A MAX
–
, and the maximum allowable
–
(
.
)
http://www.fairchild-
www.fairchildsemi.com
(30)