SMSC USB2250i User Manual
Page 19
Ultra Fast USB 2.0 Multi-Slot Flash Media Controller
Datasheet
SMSC USB2250/50i/51/51i
19
Revision 1.1 (05-29-08)
DATASHEET
Notes:
1. Hot-insertion capable card connectors are required for all flash media. It is required for the SD
connector to have a Write Protect switch. This allows the chip to detect the MMC card.
2. nMCE is normally asserted except when the 8051 is in standby mode.
3. Refer to PWR_MGMT_CTL1 register for controlling pull-up / down resistors associated with the
pins as well as the individual card control registers.
DIGITAL POWER, and GROUND
1.8V Digital Core
Power
VDD18
49
All VDD18 pins must be connected together
on the circuit board.
+1.8V Core power. If the internal regulator is
enabled, then this pin must have a 1.0
μ
F (or
greater) ±20% (ESR <0.1
Ω) capacitor to
VSS.
3.3V Power &
Voltage
Regulator Input
VDD33
15
50
65
77
104
3.3V Power & Voltage Regulator Input
Ground
VSS
9
17
51
75
81
102
122
126
Ground Reference.
Table 5.1 USB2250/50i/51/51i 128-Pin VTQFP Pin Descriptions (continued)
NAME
SYMBOL
128-PIN
VTQFP
BUFFER
TYPE
DESCRIPTION