IC BUCK SYNC ADJ 6A 25MLP

FAN2106MPX

Manufacturer Part NumberFAN2106MPX
DescriptionIC BUCK SYNC ADJ 6A 25MLP
ManufacturerFairchild Semiconductor
SeriesTinyBuck™
TypeStep-Down (Buck)
FAN2106MPX datasheet
 


Specifications of FAN2106MPX

Internal Switch(s)YesSynchronous RectifierYes
Number Of Outputs1Voltage - Output3 ~ 21 V
Current - Output6AFrequency - Switching300kHz ~ 600kHz
Voltage - Input3 ~ 24 VOperating Temperature-10°C ~ 85°C
Mounting TypeSurface MountPackage / Case25-MLP
Power - Output2.8WMounting StyleSMD/SMT
Operating Temperature Range- 10 C to + 85 COutput Voltage0.4 V to 3.2 V
Primary Input Voltage24VNo. Of Outputs1
Output Current6ANo. Of Pins25
Filter TerminalsSMDOutput Current Max6A
Rohs CompliantYesInput Voltage Primary Max24V
For Use WithFEB167 - BOARD EVAL FOR FAN2106Lead Free Status / RoHS StatusLead free / RoHS Compliant
Other namesFAN2106MPXTR  
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MOSFET is fully enhanced. The fault latch is set
immediately upon detection.
The OV and high-side short fault protections are active
all the time, including during soft-start.
Over-Temperature Protection (OTP)
The chip incorporates an over-temperature protection
circuit that sets the fault latch when a die temperature of
about 150°C is reached. The IC restarts when the die
temperature falls below 125°C.
Auto-Restart
After a fault, EN pin is discharged by a 1µA current sink
to a 1.1V threshold before the internal 800KΩ pull-up is
restored. A new soft-start cycle begins when EN
charges above 1.35V.
Depending on the external circuit, the FAN2106 can be
configured to remain latched-off or to automatically
restart after a fault.
Table 1. Fault / Restart Configurations
EN Pin
Controller / Restart State
Pull to GND
OFF (Disabled)
No Restart – Latched OFF
Pull-up to V
with 100K
CC
(After V
Open
Immediate Restart After Fault
New Soft-Start Cycle After:
Cap. to GND
t
DELAY
When EN is left open, restart is immediate.
If auto-restart is not desired, tie the EN pin to the VCC
pin or pull it HIGH after V
comes up with a logic gate
CC
to keep the 1µA current sink from discharging EN to
1.1V. Figure 23 shows one method to pull up EN to V
for a latch configuration.
15
100K
14
3.3n
Figure 23.
Enable Control with Latch Option
Power-Good (PGOOD) Signal
PGOOD is an open-drain output that asserts LOW
when V
is out of regulation, as measured at the FB
OUT
pin.
Thresholds
are
specified
Specifications section. PGOOD does not assert HIGH
until the fault latch is enabled (T1.0) (see Figure 22).
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.0
Application Information
Bias Supply
The FAN2106 requires a 5V supply rail to bias the IC
and provide gate-drive energy. Connect a ≥ 1.0µf X5R
or X7R decoupling capacitor between VCC and PGND.
Since V
supply current is frequency and voltage dependent.
Approximate V
I
CC
(
mA
)
where frequency (f) is expressed in KHz.
Setting the Output Voltage
The output voltage of the regulator can be set from 0.8V
to 80% of V
R
in Figure 1). For output voltages > 5V, output
BIAS
current rating may need to be de-rated depending upon
the ambient temperature, power dissipated in the
package and the PCB layout.
The external resistor divider is calculated using:
0
8 .
V
Comes Up)
CC
R
BIAS
Connect R
(ms)=3.9 • C(nf)
If R1 is open (see Figure 1), the output voltage is not
regulated eventually causing a latched fault after the
soft start is complete (T1.0)
If the parallel combination of R1 and R
internal SS ramp is not released and the regulator does
not start.
CC
Setting the Switching Frequency
Switching frequency is determined by an external resistor,
VCC
R
connected between the R(T) pin and AGND:
T,
FAN2106
R
Ω
T
K (
)
where R
EN
The regulator cannot start if R
Calculating the Inductor Value
Typically the inductor value is chosen based on ripple
current (ΔIL), which is chosen between 10 to 35% of the
maximum DC load. Regulator designs that require fast
transient response use a higher ripple-current setting,
while regulator designs that require higher efficiency
keep ripple current on the low side and operate at a
lower switching frequency. The inductor value is
calculated by the following formula:
in
the
Electrical
11
is used to drive the internal MOSFET gates,
CC
current (I
) can be calculated using:
CC
CC
V
5
=
+
+
CC
. 4
58
[(
. 0
013
)
f (
128
227
by an external resistor divider (R1 and
IN
V
0
8 .
V
=
OUT
+
650
nA
R
1
between FB and AGND.
BIAS
is ≤ 1KΩ, the
BIAS
6
(
10
/
) f
135
=
65
is in KΩ and frequency (f) is in KHz.
T
is left open.
T
(1)
)]
(2)
(3)
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