IFX 80471SK V50 Infineon Technologies, IFX 80471SK V50 Datasheet - Page 23

• Manufacturer Part Number: IFX 80471SK V50
• Manufacturer: Infineon Technologies

Specifications of IFX 80471SK V50

• Packages: PG-DSO-14
• Comment: Vin up to 60V; external MOS; PG-DSO-14
• Vq (max): 5.0 V
• Iq (max): 2,300.0 mA
• Iq (typ): 130.0 µA
• Output: Buck Converter

7.3.1
The formula to calculate the resistor divider for the sense comparator is basically the same as for the feedback
divider in section before. With the selected resistor R
lower sense threshold V
For high accuracy and low ohmic resistor divider values the on-resistance of the SI_GND NMOS (typ. 100Ω) has
to be added to R
7.4
The diagram below shows the typical behavior of the reset output in dependency on the input voltage V
output voltage V
Figure 4
7.5
The IFX80471 operates with a duty cycle up to 100%. This feature allows to operate with the lowest possible drop
voltage at low battery voltage as it occurs at cold cranking. The MOSFET is turned on continuously when the
supply voltage approaches the output voltage level, conventional switching regulators with less than 100% duty
cycle would fail in that case.
Data Sheet
V
V
V
V
V
IN
VOUT
FB
RD
RO
Battery sense comparator - voltage divider
Undervoltage reset - delay time
Reset timing
100% duty-cycle operation and dropout
VOUT
SI2
t
.
rd
or V
SI, low
FB
shutdown
.
thermal
t
rr
the resistor R
t
rd
SI1
R
SI1
is given to:
=
voltage
under
R
SI2
SI2
22
, the desired threshold of the input voltage V
⋅
⎛
⎝
V
------------------ - 1
V
IN UV
SI low
t
< t
rd
,
,
rr
–
⎞
⎠
over
load
t
rd
Application Information
Rev. 1.0, 2011-02-07
V
V
V
V
VOUT, RT
FB,RT
RD, UT
RD, LT
t
t
t
t
IN, UV
IFX80471
and the
IN
, the