8
6568AX–SMS–23Oct08
AT90SCR100
SUMMARY PRELIMINARY
3.1 Typical Application
Table 3-2. External Components, Bill Of Materials
Reference Description Value Comment
R1, R2
R3, R4
USB Pad Serial Resistor 22Ω +/-10% -
R5 CIO Pull-up Resistor 10KΩ +/-10% (Optional) Can be required for high speed communication
Rs DCDC Sense Resistor
200mΩ +/-2%
125mW
Current Sensing: Overcurrent detection
C1
Power Supply Decoupling
capacitor
4.7μF +/-10%
Maximum application capacitance allowed by USB
standard is 10μF
C2 Power Supply Filter capacitor 100nF -
C3
Internal Core Regulator
Decoupling capacitor
2.2μF +/-10% Used for internal regulator stability
C4
Internal USB Regulator
Decoupling capacitor
2.2μF +/-10% Used for internal regulator stability
C5, C6 PLL Filter capacitors 47pF +/-10% -
C7, C8 RTC Filter capacitors 22pF +/-10% Only if Real Time Counter is used.
C9 DCDC Decoupling Capacitor
10μF +/-10%
esr=100mΩ
Tantalum capacitor is needed
Recommended: AVX: TPSE106-035-200
L1 DCDC inductance
6.8μH
esr=20.2mΩ
Recommended: Gowanda: SMP3316LP-681M
Q1 Crystal 8.0 Mhz
Q2 Real Time Crystal 3.768 Mhz Only if Real Time Counter is used
Rled/Dled LED mechanism -- Depends on the configuration of the Led Controller
Vss
C1
3.3V
C2
R1
R2
C3 C4
Vss2
Vss3
AVss
CVcc
CVsense
CC4
CC8
CIO
CVss
RST
D+
D-
D+
D-
RESET
: As DCDC generates noise, we encourage the use of
another supply power than global Vcc, if possible.
Vcc4
Vcc3
Vcc2
Vcc1
Vdcdc
DVcc
XTAL1 XTAL2
UCAP
Vcc
AT90SCR100
Host
C5 C6
Q1
3.3V
R3
R4
R5
Rs
Rled
Dled
RTC1 RTC2 Led0
Li
Lo
C7 C8
L1
Q2
C9
Card Vcc
Card C4/D+
Card C8/D-
Card IO
(1)
(1)
3.3V
