MAX14502AETL+ Maxim Integrated Products, MAX14502AETL+ Datasheet - Page 31

• Manufacturer Part Number: MAX14502AETL+
• Description: IC CARD READER USB-SD 40-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Smart Card Interface ICr

Specifications of MAX14502AETL+

• Applications: USB
• Interface: I²C
• Voltage - Supply: 1.8 V ~ 3.3 V
• Package / Case: 40-TQFN Exposed Pad
• Mounting Type: Surface Mount
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 21. Host Card Detection Schemes
The SD port analog switches change states immediately
whether the MAX14500–MAX14503 are in Sleep mode
(WAKEUP = 0) or awake. If the internal USB Hi-Speed
SD card reader is in operation, the SD card switches for
the selected path are opened automatically. Any writes
to the SD port switch bits for that path are ignored. The
SD port analog switches for the path not being used for
the card reader are controllable by the host µP, and any
writes to these bits affect state changes immediately.
The MAX14500–MAX14503 provide an analog switch to
pass the card present signal on SD card slot 1. This
allows the host µP to continue using the SD slot card
present switch (see Figure 21). The internal analog
switch can be bypassed if an alternate algorithm is
used to detect card data change. The second SD card
path does not provide this analog switch so if this path
is used for another SD card socket, an alternate card-
detection mechanism for the host µP may be needed. If
the second SD card path is used for an SD interface
NAND chip, no card detection is required.
The MAX14500–MAX14503 do not use the SD card slot
switch to detect insertion and removals. Instead, a pro-
______________________________________________________________________________________
SD CARD
SD CARD
MECHANICAL CARD
MECHANICAL CARD
DETECT SWITCH
DETECT SWITCH
SD Port Switches
CCRD_PRST
CDAT1_[3:0]
CDAT2_[3:0]
Card Detection
CCMD1
CCMD2
CCLK1
CCLK2
MAX14500–MAX14503 SD
MAX14500–MAX14503 SD
PORT1 SWITCH
PORT2 SWITCH
Hi-Speed USB-to-SD Card
tocol-based detection mechanism is used that polls for
the presence or absence of an SD card. This allows
both path 1 and path 2 to support an SD card slot with
removable SD cards without a connection between
the MAX14500–MAX14503 and the SD socket card pre-
sent switch. The pullup voltage for the card slot detec-
tion may be any voltage equal to or less than V
The MAX14500–MAX14503 enumerate to the USB
mass storage class and appear as a USB mass stor-
age device on most operating systems.
The MAX14500–MAX14503 support USB Hi-Speed and
full-speed operation. The MAX14500–MAX14503 operate
at 480Mbps when plugged into a Hi-Speed USB host,
and at 12Mbps when plugged into a full-speed host.
Using I
I
identification (PID). The programmed 16-bit default val-
ues are shown in the Register Map section. The factory
default values can be replaced with your company’s VID
and PID.
2
C registers for vendor identification (VID) and product
Readers with Bypass
HCRD_PRST
2
C, the MAX14500–MAX14503 have dedicated
HDAT1_[3:0]
HDAT2_[3:0]
HCMD1
HCMD2
HCLK1
HCLK2
≤ V
≤ V
SD
SD
USB Hi-Speed vs. Full-Speed
CARD PRESENT INPUT
CARD PRESENT INPUT
HOST SD PORT
HOST SD PORT
Enumeration
USB VID/PID
SD
.
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