ATEVK527 Atmel, ATEVK527 Datasheet - Page 9

• Manufacturer Part Number: ATEVK527
• Description: KIT EVAL PWM AVR USB 4 SERIES
• Manufacturer: Atmel
• Series: AVR®r

Specifications of ATEVK527

• Main Purpose: Power Management, Battery Charger
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega16U4, ATmega32U4
• Primary Attributes: 1 Cell- Li-Ion
• Secondary Attributes: Graphical User Interface, USB Interface
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.5 EVK527 Revision
3.6 Buck converter
7801A-AVR-06/08
• Self-Power Self powered functions can draw up to 100mA from VBUS and the
The current to power the EVK527 and to charge the battery comes from VBUS. The
EVK527 must limit the charge current if needed.
An easy solution is to modify the I charge parameter in the lookup table.
For example, a 550mAh battery allows a 260mA charging current. A modification of
this parameter to 90mA (for example) allows connecting the charger on a Low Power
Bus, knowing that the EVK527 consumption with an 8MHz oscillator is about 10mA.
In this case, the prequalification current must also be limited to 90mA.
The EVK527 Rev1.0.0 must be updated as follows:
• The shunt resistor must be connected between PF0 and PF1 to use the differential
• Gate pin and Source pins of Q1A must be disconnected.
• R6 and R7 new values are 13kOhms
• R3 new value is 1Ohm
Schematics given in §6 don’t show these modifications.
A buck converter is integrated on EVK527 to control the battery voltage and the
battery current. The switch is controlled by the High speed PWM output.
Figure 3-2. Buck converter schematic.
rest from another source.
input mode. PF0 must replace PD4 and SP6 must be “without solder” (different of
default configuration).
BATTERY
AVR146
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