AN11001
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© NXP B.V. 2011. All rights reserved.
Application note
Rev. 1 — 7 March 2011
3 of 17
NXP Semiconductors
AN11001
CBTL02042A switching application for mSATA, PCIe Mini-Card
1. Introduction
NXP’s CBTL02042A (shown in
) is a 3.3 V, 2-to-1 multiplexer/de-multiplexer
specially designed for switching between PCIe Gen 2 (up to 5 Gbit/s) and SATA Gen 2
(up to 3 Gbit/s) signals, with features such as low insertion loss (
1.2 dB at 2.5 GHz),
low crosstalk (
30 dB at 2.5 GHz), and low operating power consumption (< 1 mA). A
motherboard manufacturer can use CBTL02042A for multiplexing between PCIe Gen 2
and SATA signals connecting to an mSATA/Mini-Card socket. This document discusses
system level design guidelines and considerations while using CBTL02042A in a
Mini-Card/mSATA sub-system.
2. Mini-Card and mSATA applications
Both mSATA (from SATA-IO) and Mini-Card (from PCI SIG) share the same form-factor
and similar electrical pinout assignments on their connectors. Mini-Cards are PCI Express
(or PCIe)-based devices, and PCIe interface signals are accessible on the connectors. An
mSATA device’s connector replaces PCIe interface signals with SATA interface, but with
power and ground signals assigned to the same connector pins as Mini-Card’s. There
was no clear mechanism to distinguish if a mSATA drive or a Mini-Card device is plugged
into the socket until recently that SATA-IO issued an ECN change (ECN #45) to re-define
pin 43 on mSATA connector as ‘no connect’ instead of ‘return current path’ (or GND).
Fig 1.
CBTL02042A functional block diagram
002aaf875
CBTL02042A
B0_P
B0_N
B1_P
B1_N
C0_P
C0_N
C1_P
C1_N
A0_P
A0_N
A1_P
A1_N
SEL
XSD
Table 1.
mSATA and Mini-Card pin assignments
Pin
mSATA
Description
Mini-Card
P1
reserved
no connect
WAKE#
P2
+3.3 V
3.3 V source
+3.3 V
aux
P3
reserved
no connect
COEX1
P4
GND
return current path
GND
P5
reserved
no connect
COEX2
P6
+1.5 V
1.5 V source
+1.5 V
P7
reserved
no connect
CLKREQ#
