IFX 80471SK V50 Infineon Technologies, IFX 80471SK V50 Datasheet - Page 22

• 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
Note: The following information is given as a hint for the implementation of the device only and shall not be
7.1
The IFX80471 step-down DC-DC controllers are designed primarily for use in industrial applications and offer a
large flexibility in the input voltage range they can handle. Using an external P-MOSFET and current-sense
resistor allows design flexibility and the improved efficiencies associated with high-performance P-channel
MOSFETs. The unique, peak current-limited, PWM/PFM control scheme gives these devices excellent efficiency
over wide load ranges, while drawing around 100µA current from the battery under no load condition. This wide
dynamic range optimizes the IFX80471 for applications, where load currents can vary considerably as individual
circuit blocks are turned on and off to conserve energy. Operation to a 100% duty cycle allows the lowest possible
dropout voltage, maintaining operation during cold cranking. High switching frequencies and a simple circuit
topology minimize PC board area and component costs.
7.2
The output voltage is sensed either by an internal voltage divider connected to the VOUT pin (IFX80471SKV50,
fixed 5V version) or an external divider from the Buck output voltage to the FB pin (IFX80471SKV, adjustable
version). The Vout pin has to be connected always to the Buck converter output regardless which output voltage
for the adjustable version is desired.
To determine the resistors of the feedback divider for the desired output voltage V
R
V
be adjusted in a range from 1.25V to 15V. However the integrated Reset function will only be operational if the
output voltage level is adjusted to >7V.
Also the current consumption will be increased in PFM mode in the range between
1.25V and 7V.
7.3
Connecting SI_ENABLE to 5V causes SI_GND to have low impedance. Thus the SI comparator is in operation
and can be used to monitor the battery voltage. SO output signal is valid. Connecting SI_ENABLE to GND causes
SI_GND to have high impedance. Thus the SI comparator is not able to monitor the battery voltage. SO output
signal is invalid.
Data Sheet
FB
FB2
is the threshold of the error amplifier with its value of typical 1.25V which shows that the output voltage can
between 5kΩ and 500kΩ and obtain R
regarded as a description or warranty of a certain functionality, condition or quality of the device.
SI_Enable
Application Information
General
Output voltage at adjustable version - feedback divider
FB1
R
FB1
with the following formula:
=
R
FB2
21
⋅
⎛
⎝
---------------- 1
V
V
FB th
OUT
,
–
⎞
⎠
OUT
at the IFX80471SKV select
Application Information
Rev. 1.0, 2011-02-07
IFX80471