TXS0108E: May I have some question for the part different ?

Dear SIR:

Thanks for your reply.

regarding "I would like to know more information regarding application, interface involved, voltage translation requirement.if you can provide."

reply as below:

For Micro SD 1.8V/3.3V  card reader translation requirement.

 --------------------Switch between condition1 and condition 2 as below --------------------

Condition 1: VCCA pin is 1.8V  ,VCCB pin is 3.3V 

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 1.8V (External pull High 1.8V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 3.3V  (3.3V Card  Device)

Condition 2: VCCA pin is 1.8V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 1.8V (External pull High 1.8V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 1.8V  (1.8V Card  Device)

Condition 3: VCCA pin is 3.3V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 3.3V (External pull High 3.3V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 3.3V  (3.3V Card  Device)

Condition 4: VCCA pin is 3.3V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 3.3V (External pull High 3.3V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 1.8V  (1.8V Card  Device)

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Or Would you have any advice for above ?

Thanks

Dear SIR:

Thanks for your reply.

regarding "I would like to know more information regarding application, interface involved, voltage translation requirement.if you can provide."

reply as below:

For Micro SD 1.8V/3.3V  card reader translation requirement.

 --------------------Switch between condition1 and condition 2 as below --------------------

Condition 1: VCCA pin is 1.8V  ,VCCB pin is 3.3V 

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 1.8V (External pull High 1.8V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 3.3V  (3.3V Card  Device)

Condition 2: VCCA pin is 1.8V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 1.8V (External pull High 1.8V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 1.8V  (1.8V Card  Device)

Condition 3: VCCA pin is 3.3V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 3.3V (External pull High 3.3V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 3.3V  (3.3V Card  Device)

Condition 4: VCCA pin is 3.3V  ,VCCB pin is 3.3V

Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  signal  is 3.3V (External pull High 3.3V by resistor  for Host Chip)

Pin B1 ,B2, B3, B4, B5, B6, B7,B8  signal  is 1.8V  (1.8V Card  Device)

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Or Would you have any advice for above ?

Thanks

Dear SIR:

Thanks for your reply.

May I double confirming regarding your reply in detail:

(1)As your replay mention that "without external resistors",Is that meaning "Only Condition 3  or for ALL condition (Condition 1,2,3,4) ?"

(2)As your replay mention that "without external resistors",Is that meaning "Only Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8 side   or  for ALL condition A,B Side

     (Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8  and Pin B1 ,B2, B3, B4, B5, B6, B7,B8)?"

(3) Regarding above (1) and (2) ,Is that meaning TXS0108E have "Internal pull High" ,In detail as below ?

     Pin A1 ,A2, A3, A4, A5, A6, A7 ,A8 have internal pull High to VCCA

     Pin B1 ,B2, B3, B4, B5, B6, B7,B8 have internal pull High to VCCB

     Therefore,"without external resistors" meaning "no need add external pull high ,because TXS0108E have internal pull high ,already. ,Right?

(4) Is possible TXS0108E can replace T3GF3WBG  ?

Reply as mention <Reply>

Regarding your  question "what is the max data rate intended? Are all the ports IO or will some of them be designated as clock signals?"

<Reply>I don't understanding the question meaning in detail ,Could you found answer from below table for "what is the max data rate intended?"?

Are all the ports IO or will some of them be designated as clock signals?"

<Reply> That have include data pin and CMD pin and clock pin .

Yes, the TXS has internal pull high resistors which means for all the conditions 1,2,3,4 you do not need external resistors.
The data rate is the max frequency of operation using the device on the IO ports.

The table here has max clk rate of 208Mhz and this cannot be achieved using the TXS device.
would the IO ports be operated at the max rate?

Dear SIR:

Thank for your reply.

Regarding you mention that "The table here has max clk rate of 208Mhz and this cannot be achieved using the TXS device."

Would you have recommend any other  product  replace TXS0108E for max clk rate of 208Mhz ?

[ May I know TXS108E or TXS Device What max data rate can be achieved ? <max clk rate of 208Mhz and this cannot be achieved >]

    (Because "Host side(chip)" datasheet didn't mention that detail information ,but seems that table(from Micro SD spec.) have mention that  max clk rate of 208Mhz.

Therefore,We don't know that IO ports will be operated at the max rate or not.)

For "safe", Is possible "Would you have recommend any other  popular part  as "TXS0108E " and  208Mhz  can be achieved TI product(solution)  replace TXS0108E for meet max clk rate of 208Mhz ?"

Thanks

Alex,

The clock's 208 MHz is 416 Mbps which cannot be supported by auto bidirectional family of devices.

The SN74AVC1T45 is direction controlled translator and it supports up to 500 Mbps which is suitable for the SD3.0 operation.

However, this would be a 2 chip solution. SN74AVC1T45 for clock and TXS0108 for the IOs. The TXS0108 is rated for 110 Mbps data rate support only.

Dear SIR:

Thanks for your advice and recommend. 

May I double confirming regarding "  this would be a 2 chip solution. SN74AVC1T45 for clock and TXS0108 for the IOs."

What's the consider in detail regarding "  this would be a 2 chip solution. SN74AVC1T45 for clock and TXS0108 for the IOs."?

(For example: If  we only use  SN74AVC1T45  x 8 pcs  for replace SN74AVC1T45  x 1 pcs + TXS0108 x1 )

Or SN74AVC1T45  x 8 pcs have any issue  Or..SN74AVC1T45 can't  for the IOs...Or....?

Another Question: Seems TXS0108 datasheet have mention that " Maximum Data Rates – 110 Mbps (Push Pull) – 1.2 Mbps (Open Drain)"

                                 What's or How to Switch(or decide) between  110 Mbps (Push Pull)  and  1.2 Mbps (Open Drain) ?

                                 (Have any Enable pin or Strap pin or .....for  Switch(or decide) between  110 Mbps (Push Pull)  and  1.2 Mbps (Open Drain) ?)

Thanks

Dear SIR:

Thanks for your advice and recommend. 

May I double confirming regarding "  this would be a 2 chip solution. SN74AVC1T45 for clock and TXS0108 for the IOs."

What's the consider in detail regarding "  this would be a 2 chip solution. SN74AVC1T45 for clock and TXS0108 for the IOs."?

(For example: If  we only use  SN74AVC1T45  x 8 pcs  for replace SN74AVC1T45  x 1 pcs + TXS0108 x1 )

Or SN74AVC1T45  x 8 pcs have any issue  Or..SN74AVC1T45 can't  for the IOs...Or....?

Another Question: Seems TXS0108 datasheet have mention that " Maximum Data Rates – 110 Mbps (Push Pull) – 1.2 Mbps (Open Drain)"

                                 What's or How to Switch(or decide) between  110 Mbps (Push Pull)  and  1.2 Mbps (Open Drain) ?

                                 (Have any Enable pin or Strap pin or .....for  Switch(or decide) between  110 Mbps (Push Pull)  and  1.2 Mbps (Open Drain) ?)

Thanks

Alex,

Yes, the suggestion from me was for a 2 chip solution. 

The SN74AVC8T245 or the SN74AXC8T245 doesn't support 208 MHz. The SN74AVC1T45 device can support 500 Mbps for the clock. Since the other IOs you had mentioned, all had pull-up resistors which is supported by TXS. The TXS can handle both unidirectional and bidirectional interface.

SN74AVC1T45 should not be used with external resistors. ( assuming the signals are all open drain bidirectional). The AVC is direction controlled using an external DIR pin and hence the signals cannot be bidirectional which changes at the same time.