SE98ATP datasheet(15/43 Pages) NXP

15 / 43 page

SE98A_4

Product data sheet

Rev. 04 — 25 November 2009

15 of 43

NXP Semiconductors

SE98A

DDR memory module temp sensor, 1.7 V to 3.6 V

7.10 Hot plugging

The SE98A can be used in hot plugging applications. Internal circuitry prevents damaging

current backflow through the device when it is powered down, but with the I2C-bus,

EVENT or address pins still connected. The open-drain SDA and EVENT pins (SCL and

address pins are input only) effectively places the outputs in a high-impedance state

during power-up and power-down, which prevents driver conflict and bus contention. The

50 ns noise filter will filter out any insertion glitches from the state machine, which is very

robust and not prone to false operation.

The device needs a proper power-up sequence to reset itself, not only for the device

I2C-bus and I/O initial states, but also to load specific pre-defined data or calibration data

into its operational registers. The power-up sequence should occur correctly with a fast

ramp rate and the I2C-bus active. The SE98A might not respond immediately after

power-up, but it should not damage the part if the power-up sequence is abnormal. If the

SCL line is held LOW, the part will not exit the power-on reset mode since the part is held

in reset until SCL is released.

A = ACK = Acknowledge bit. NA = Not Acknowledge bit. W = Write bit = 0. R = Read bit = 1.

Fig 11. SMBus/I2C-bus word read from register with a pre-set pointer

123456789

D15

D14

D13

D12

D11

D10

returned most significant byte data

ACK

by host

SCL

SDA

123456789

SCL

SDA

device address and read

ACK

by device

(cont.)

002aab414

123456789

returned least significant byte data

STOP

NACK

by host

START

by host

SE98ATP Datasheet(PDF) 15 Page - NXP Semiconductors

SE98ATP Datasheet(HTML) 15 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

Datasheet Download

Link URL