Datasheet

Application Information
13−6
SLLS535E − April 2008TUSB6250
13.5 CompactFlashE Storage Card Reader Application
13.5.1 Brief Introduction
CompactFlash storage cards provide a flash-memory-technology-independent interface to access the flash
cards. The CompactFlash storage cards include an on-card intelligent microcontroller subsystem that
provides a high-level interface to the host computer with the following key features:
• Standard ATA register and command set (same as found on most magnetic disk drives)
• Host independence from details of erasing and programming flash memory
• 512-byte sector size of the CompactFlash storage card is the same as that in an IDE magnetic disk drive.
CompactFlash storage cards electrically comply with the PCMCIA ATA (PC card ATA) standard, which is a
superset of the ATA protocol and based on the following standards:
• PC card standard, release 2.01 and
• ATA standard, release 3.1
CompactFlash storage cards are required to support all three types of interface protocols:
• PC card memory mode—The CompactFlash storage card operating in this mode follows PC card ATA
protocol using PCMCIA memory mode.
• PC card I/O mode—The CompactFlash storage card operating in this mode follows PC card ATA protocol
using PCMCIA I/O mode.
• True-IDE mode—The CompactFlash storage card operating in this mode follows IDE protocol and acts
as an IDE disk. The CompactFlash storage card reader implemented based on the TUSB6250, only
supports this mode.
13.5.1.1 Power Supply Requirements
The CompactFlash storage card is a dual-voltage product, which operates in either of the following voltage
ranges:
• 3.3 V ±5%
• 5 V ±10% (±5% for industrial versions)
The CompactFlash storage card reader implemented with the TUSB6250 can support a single voltage of
3.3 V.
Table 13−2. CompactFlashE Power Consumption (Reference Only)
POWER SOURCE FROM READER OPERATING CONDITION
CompactFlashE STORAGE CARD
POWER CONSUMPTION
(SLOW−FAST)
Sleep 200 µA
DC input voltage (V
CC
= 3.3 V)
Reading 32 mA−45 mA
DC input voltage (V
CC
= 3.3 V)
100 mV maximum ripple (p-p)
Writing 32 mA−60 mA
100 mV maximum ripple (p-p)
Read/write peak 150 mA/50 µs
NOTE: These values are for reference purposes only.
NOTE: The CompactFlash storage card reader designer must pay attention to the USB bus power suspend current
limit (500 µA). There is only 300-µA suspend current budget left on the reader when a CompactFlash storage
card remains inserted and operates in a sleep state.
CompactFlash is a trademark of SanDisk Incorporated.